JP4416831B1 - Inspection device, inspection method, and inspection program - Google Patents

Abstract

An object of the present invention is to make it possible to perform a covering inspection of a covering wire more easily.
In an inspection apparatus 100 for inspecting the presence or absence of a dielectric flaw or a pinhole in an electric wire C coated with a dielectric, a TM01 mode microwave standing wave is excited by a cavity resonator 11 and a TM01 mode is excited. By passing the electric wire C through the center of the rotating magnetic field, an alternating current I having a microwave frequency is passed through the electric wire C. And the microwave radiated | emitted from the electric wire C which continues from the inside of the cavity resonator 11 to the exterior is received, and two antennas offset in the length direction of the electric wire C are made with respect to the axis of the electric wire C, etc. Adjacent to the angle, the phase velocity of the alternating current I is obtained based on the differential signal. When a part where the phase velocity is not constant is detected, it is determined that the covering is abnormal for the part.
[Selection] Figure 1

Description

  The present invention relates to an inspection apparatus, an inspection method, and an inspection program, and more particularly to an inspection apparatus, an inspection method, and an inspection program for inspecting a state of a dielectric covering a conductor wire.

  A coated wire whose conductor surface is covered with a dielectric material such as an electric wire is inspected for the presence of scratches, pinholes, peeling, etc. before shipment. This is because the pressure resistance is affected if the coating is insufficient. The coating inspection methods include a method of irradiating the coating with laser light and utilizing the reflected light, a method of detecting a coating abnormality by processing the image of the coating taken with a high-sensitivity camera, There is known a method of detecting ultraviolet rays that emit light by energizing a voltage to cause insulation breakage or air ionization in a pinhole.

In the above-described coating inspection using laser light, laser light is irradiated to a point to be inspected, and abnormality of the coating is inspected based on the intensity of the reflected light. At this time, the laser beam must be accurately applied to the inspection point, and the reflected light of the inspection point must be accurately incident on the light receiving unit. Therefore, it is not suitable for the inspection of the coated wire which is shaken or vibrated.
In addition, in the coating inspection using laser light, only the irradiated surface can be inspected, so if you want to inspect the entire surface of the electric wire etc., you can scan the surface of the conductive wire with laser light, or use the laser light source It must be prepared in a plurality of directions around the axis of the conductive wire to be inspected. Therefore, when the coating inspection is performed with the laser beam, the inspection apparatus is inevitably large and expensive.

  Even when covering inspection is performed using a high-sensitivity camera, the inspection apparatus becomes too large and the apparatus becomes expensive. High-sensitivity cameras are expensive in the first place, and in order to acquire images so as to cover the entire circumference of the coated wire moving at high speed, multiple high-sensitivity cameras are prepared, or the high-sensitivity camera is installed around the coated wire. This is because a device for taking a picture while moving in the direction is required. In addition, a processing apparatus capable of executing high-speed image processing is also required in order to detect a covering abnormality from the captured image. In particular, if you want to perform coating inspection on wires that move at a high speed as described later, in addition to high sensitivity, you will need a high-speed camera that can take high-speed images, and images taken sequentially at high speed will be imaged at high speed. A processing device is also required.

  The method for detecting the ozone concentration is dangerous because a high voltage needs to be applied to the electric wire, and a device for detecting the absorbance of ultraviolet rays irradiated to ozone is also required. Therefore, the inspection apparatus becomes large and the apparatus becomes expensive.

  By the way, it is necessary to inspect the coating of the electric wire C at a factory before shipment. In order to complete the inspection in a practical time while accurately inspecting an electric wire of several tens to several hundreds of meters, it is preferable to inspect in the middle of the production line. This is because there is no need to provide a separate inspection process, so that production efficiency is improved. However, the electric wires in the production line are moving at a high speed of several hundreds m / min in the length direction, and the above-described technology has not been able to meet such a demand.

  In addition, in the coating inspection, not only the presence of defects such as coating scratches, pinholes, peeling, etc., but also the uniformity of coating and the degree of adhesion between coatings when multiple types of coatings are stacked, etc. It is preferable that the performance of the coating can be inspected. However, since the uniformity and the degree of adhesion of the coating cannot be measured from the surface, the above-described laser light, high-sensitivity camera, and method using ozone concentration cannot be used. Of course, although it is possible to inspect using a large-scale apparatus such as CT (Computed Tomography), development of a simpler inspection method has been desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an inspection apparatus, an inspection method, and an inspection program that can inspect the state of a dielectric covering a conductive wire more easily.

In order to solve the above problems, an inspection apparatus of the present invention is an inspection apparatus for inspecting a state of a dielectric covering a conductive wire, and a standing wave of an electromagnetic wave having a predetermined frequency is applied to a cavity resonator in a TM01 mode. An excitation unit that excites and passes the alternating current of the predetermined frequency to the conductive wire penetrating the cavity resonator by electromagnetic induction; and an electromagnetic wave radiated from the conductive wire by the alternating current flowing through the conductive wire , The state of the dielectric is determined based on at least one of a receiving unit that receives the electromagnetic wave of the predetermined frequency radiated through the dielectric and an amplitude intensity and a phase around the electromagnetic wave received by the receiving unit. And a determination unit.

  In the above configuration, it is assumed that the conductive wire is covered with a dielectric, the conductive wire is basically uniform and uniform, and the phase is constant. In addition, the coating is basically prepared in advance so as to be in a homogeneous state, but depending on the creation situation, the coating may be in a non-homogeneous state that deviates from a state in which a certain amount of error is taken into consideration. In other words, the coating in the cross section perpendicular to the conductive wire shows almost the same cross section wherever the conductive wire is cut if it is in a homogeneous state, but it looks different from other cross sections in a non-homogeneous state. Presents.

  The inspection apparatus can inspect the state of such a cross section from the outside of the coating in a nondestructive manner. That is, the excitation unit excites a standing wave of an electromagnetic wave having a predetermined frequency in the cavity resonator in the TM01 mode, and causes the alternating current having the predetermined frequency to flow through the conductive wire passing through the cavity resonator by electromagnetic induction. . An electromagnetic wave radiated from the conductive wire through the dielectric by the alternating current is received by the receiving unit. The receiving unit can selectively receive the electromagnetic wave having the predetermined frequency.

  As the predetermined frequency, a frequency band in which an alternating current having the frequency becomes a skin current, such as a microwave frequency band, is particularly suitable. It is better that the state of the coating greatly affects the alternating current, and the greater the influence of the state of the coating on the alternating current, the more strongly the electromagnetic wave radiated from the conductive wire by the alternating current is more strongly affected by the state of the coating. is there. That is, it can be said that the S / N ratio of information corresponding to the state of the coating is improved in the electromagnetic wave.

As information indicating the state of the coating, the amplitude intensity and the phase around the electromagnetic wave can be used, and the determination unit determines the state of the coating using any of these. If the amplitude intensity is used, for example, the amplitude intensity differs between the electromagnetic wave radiated from the part where the covering is missing and the electromagnetic wave radiated from the part where the defect is not, so the difference is detected by setting a predetermined threshold value. it can. Further, for example, the same applies to electromagnetic waves radiated through a portion where foreign matters such as bubbles are contained in the coating.

Also, around the phase is the transmission medium is constant if homogeneous, are known to be unstable without constant as long as it is a non-homogeneous poor quality of the transmission medium. The transmission medium referred to here includes not only a conductor portion through which current actually flows, but also the influence of a coating covering the periphery thereof. That is, if the coating is homogeneous, the phase rotation is constant, but if the coating is not homogeneous, the phase rotation is indefinite. Therefore, if the surroundings of the phase are utilized, if the coating is lost or foreign matter is mixed in the coating, a change occurs in the phase of the electromagnetic wave radiated from the part, so that the abnormality of the coating can be detected.

In addition, when the conductive wire is moving in the length direction of the conductive wire, the determination unit determines the state of the dielectric based on the fluctuation around the phase of the electromagnetic wave received by the reception unit. You may comprise. This is because the amplitude intensity of the electromagnetic wave received by the receiving unit cannot be accurately measured if a conductive wire to be inspected is moved, causing a spatial variation factor due to vibration or vibration. In this respect, since the phase is not affected by the spatial variation factor, it is possible to accurately measure the circumference of the phase . Therefore, the covering state of the moving conductive wire can be accurately detected.

The receiving unit may receive the electromagnetic wave while scanning the conductive line in a predetermined direction. Of course, if the electromagnetic wave intensity radiated through the coating in the reference state is known, the normality / abnormality of the coating can be determined based on the electromagnetic wave intensity received at a specific point. However, for example, when there are multiple types of inspection objects, it is necessary to make a determination based on the reception intensity relative to the periphery of the inspection point, or to determine the reception intensity relative to the average value of the reception intensity received at each inspection point. is there. At this time, the determination unit can determine the state of the dielectric based on at least one change in amplitude intensity and phase around the electromagnetic wave received by the reception unit.

In this way, when using the phase rotation , the receiving unit detects the phase rotation of the electromagnetic wave having the predetermined frequency radiated from the conductive wire, and the determination unit detects the phase rotation of the electromagnetic wave. It can comprise so that it may judge that the said coating | cover has abnormality about the site | part exceeding the predetermined amount. In other words, on the premise that a certain level of quality is maintained in advance, a predetermined amount (threshold value) is determined in advance that the phase does not exceed this level if the quality is the same. Then, the determination unit detects around the position phase, can be around the phase to determine the state of the coating on whether more than the predetermined amount.

  By the way, as a selective aspect of the present invention for efficiently flowing an alternating current to the conductive line by the cavity resonator, the conductive line is arranged along the approximate center of the rotating magnetic field of the TM01 mode. Also good. In the TM01 mode, the center of the rotating magnetic field has the strongest electric field, and the electric field vector at the center of the rotating magnetic field is determined in one direction. In other words, if the conductive line is arranged along the center of the rotating magnetic field, the sum of the electric field vectors passing through the conductive line is maximized, so that the standing wave of the cavity resonator is changed to the alternating current flowing through the conductive line. Conversion efficiency is maximized.

  As another optional aspect of the present invention for enhancing the influence of the state of the coating on the alternating current, the excitation unit excites the standing wave in the microwave frequency band to the cavity resonator, thereby An alternating current having a microwave frequency may be passed through the wire. The alternating current of microwave frequency becomes a skin current in the conductive wire. When the alternating current becomes a skin current, most of the current flows in the vicinity of the coating, so that the interaction between the coating and the alternating current is maximized. That is, the influence of the coating state becomes more prominent due to the alternating current.

In addition, as a selective aspect of the present invention that is suitable when spatial vibration occurs in the conductive wire, the receiving unit is equiangular with respect to the axis of the conductive wire and in the length direction of the conductive wire. At least two electric field sensors arranged in an offset manner are provided, and the above-mentioned phase rotation can be detected based on a differential signal between the electric field sensors. As a method of detecting the rotation of the phase, there is a method of detecting a phase fluctuation per predetermined length of the conductive line by scanning the conductive line in the length direction and measuring the electromagnetic wave intensity at each part of the conductive line. However, in this method, the electromagnetic wave intensity varies due to the spatial vibration. Therefore, the rotation of the phase is detected by the differential of the electromagnetic wave intensity received by the two or more electric field sensors arranged offset. If it is around the phase, it does not depend on the amplitude intensity, and if it is a differential signal between adjacent electric field sensors, the gain around the phase that eliminates the influence of the spatial vibration of the conductive wire can be obtained by performing simple gain adjustment. be able to. The electric field sensor may measure a current or voltage generated according to the electric field strength of the electromagnetic wave such as an antenna antenna, or may be a refraction generated according to the electric field strength of the electromagnetic wave, like an optical electric field sensor. Any device may be used as long as it is a device that measures fluctuations in physical quantities generated in response to electric field strength.

  It should be noted that the offset distance of the electric field sensor needs to be changed so that the relative distance from the conductive wire that vibrates in space changes equally in the electric field sensor that forms a group for obtaining a differential signal. In other words, it is desirable that the offset interval between the paired electric field sensors is the shortest distance that can avoid interference between the electric field sensors. The interference referred to here is physical interference or electromagnetic interference. The closer the electric field sensor is, the smaller the spatial variation factor that occurs in the differential signal of the adjacent electric field sensor, thereby improving the reliability of the inspection result.

  The electric field sensor is preferably disposed close to the antinode of the standing wave formed when the dielectric is in a reference state. This is because the electric field strength is strongest at the antinode of the standing wave, and the fluctuation of the electric field strength can be detected with the highest sensitivity. In addition, the reference | standard state said here means the said homogeneous state.

  In addition, the said receiving part has received the said electromagnetic wave from the site | part different from the site | part which passes the inside of the cavity resonator of the said excitation part about the said conductive wire. However, when an electric field is generated between the cavity resonator and the receiving unit, the electric field distribution generated from the conductive wire is disturbed. Therefore, as an optional aspect of the present invention, it is preferable that the excitation unit and the reception unit are configured separately, and a shielding plate made of a conductor is disposed between the excitation unit and the reception unit. By arranging the shielding plate, the excitation unit and the reception unit are electromagnetically isolated from each other, so that the electric field of the conductive wire in the part where the reception unit receives the electromagnetic wave is not affected by the remote action from the excitation unit. As a result, the S / N ratio of information relating to the state of coating in the electromagnetic wave radiated from the conductive wire is improved.

  In addition, the inspection apparatus demonstrated above contains various aspects, such as being implemented in the state integrated in another apparatus, or being implemented with another method. The present invention also includes an inspection system including the above-described inspection device, an inspection method having a process corresponding to the configuration of the above-described device, an inspection program for causing a computer to realize a function corresponding to the above-described device configuration, and the inspection program recorded therein It can also be realized as a computer-readable recording medium. The inventions of these inspection system, inspection method, inspection program, and medium on which the inspection program is recorded also have the above-described operations and effects. Of course, the configurations described in claims 2 to 10 are also applicable to the system, the method, the program, and the recording medium.

As described above, according to the present invention, it is possible to provide an inspection apparatus capable of performing a conductive wire coating inspection more simply.
According to the invention of claim 2, it is possible to accurately detect the covering state of the moving conductive wire.
Moreover, according to the invention concerning Claim 3, even when there exist multiple types of test object, a covering state can be test | inspected.
Moreover, according to the invention concerning Claim 4, the receiving efficiency of the electromagnetic waves received by a conductive wire from a cavity resonator can be improved.
Moreover, according to the invention concerning Claim 5, the influence of the coating | cover with respect to the alternating current which flows into a conductive wire can be heightened.
According to the sixth and seventh aspects of the present invention, the state of the coating can be inspected without being affected by the spatial vibration even if the conductive wire generates the spatial vibration.
Moreover, according to the invention concerning Claim 8, the detection sensitivity of the fluctuation | variation of an electric field strength can be improved.
According to the invention of claim 9, it is possible to easily detect the abnormality of the coating.
According to the invention of claim 10, it is possible to improve the detection accuracy of the coating abnormality by electromagnetically separating the excitation unit and the reception unit.
According to the invention of claim 11, it is possible to provide an inspection method corresponding to the above-described inspection apparatus.
According to the invention of claim 12, it is possible to provide an inspection program for controlling the above-described inspection apparatus.

It is a block diagram which shows the structure concerning one Embodiment of this invention. It is a figure explaining the skin current of the electric wire C. FIG. It is explanatory drawing of the electromagnetic field distribution of TM01 mode. It is a perspective view which shows the structure of a cavity resonator. It is an example of a structure for exciting the TM01 mode. It is a graph explaining the circumference of a phase. It is a figure explaining the method of using the uniformity of a single section, It is a figure explaining the method of using the uniformity of an axial direction. It is a block diagram which shows the hardware constitutions of a receiving part and an analysis process part. It is a perspective view explaining the modification of antenna arrangement | positioning. It is the figure which showed notionally the electric field distribution and the positional relationship of an antenna. It is a figure which shows an example of the board | substrate structure which arrange | positions a receiving part and an analysis process part. 3 is a diagram showing an instantaneous value distribution of an electric field formed along an electric wire C. FIG. This is a test configuration for testing the detection sensitivity. It is the test result performed with the structure of FIG. It is a flowchart of a covering inspection process. It is a block diagram which shows the structure of the inspection apparatus of the modification 1. It is a side view of the uniaxial mechanical turning mechanism with which the detector of the modification 1 is provided. It is the partial sectional view which looked at the reverse feed rotation mechanism with which the rotation drive part of modification 1 is provided from the side. It is principal part sectional drawing of the fusion | fusion part of the hemostatic balloon. It is an instantaneous value of the electric field distribution of a stainless steel wire. It is a flowchart of an inspection process. It is a figure which shows the structure of the receiving part concerning the modification 2.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of the present invention:
(2) Cover inspection processing:
(3) Modification 1:
(4) Modification 2:
(5) Modification 3:
(6) Summary:

(1) Configuration of the present invention:
<Outline configuration>
FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention. As shown in the figure, the inspection apparatus 100 includes an excitation unit 10 for supplying an alternating current of a predetermined frequency to an electric wire covered with a dielectric, and a predetermined frequency radiated from the electric wire in which the alternating current of the predetermined frequency is supplied. Receiving unit 20 for receiving the electromagnetic wave, a transport mechanism 30 for transporting the electric wire in the length direction, and an analysis processing unit 40 for analyzing the electromagnetic wave received by the receiving unit 20 and inspecting the state of the covering of the electric wire. It has. Hereinafter, the structure of each part 10-40 is demonstrated in detail.

<Generate skin current with microwaves>
The excitation unit 10 generates an alternating current I having a predetermined frequency in the electric wire C. In the present embodiment, the frequency of the alternating current I is in the microwave frequency band. However, as long as the alternating current I is a frequency at which the skin current is changed, the same effect as that of the present embodiment can be obtained even if another frequency band is adopted. Further, even if the electromagnetic wave has a frequency band that does not become a skin current, the degree of influence of the dielectric state on the AC current I is reduced, but the influence is not lost. I do not care. When the alternating current I becomes a skin current, as shown in FIG. 2, the current concentrates from the conductor surface to a depth of δ.

FIG. 2 is a diagram for explaining the skin current flowing in the electric wire C. FIG. As shown in the figure, since the skin current is concentrated within the range of δ from the dielectric, the alternating current I is physical / chemical such as coating thickness, scratches, quantity, type, and homogeneity. Susceptible to condition. Therefore, these physical and chemical states are reflected around the amplitude intensity and phase of the alternating current I. Further, since the alternating current I flows through the electric wire C, an electromagnetic wave corresponding to the frequency of the alternating current I is radiated from the electric wire C. Since this electromagnetic wave is also affected by the dielectric like the alternating current I, the state of the coating can be grasped by analyzing the electromagnetic wave radiated from the electric wire C. The electromagnetic wave generation method, reception method, and analysis method will be described below.

<Non-contact current generation by cavity resonator>
When the alternating current I is passed through the electric wire C by the excitation unit 10, it is desirable to perform it in a non-contact manner. This is for preventing the coating from being damaged by the contact, and for surely passing an electric current through the electric wire C vibrating perpendicularly to the length direction as will be described later. The excitation unit 10 of the present embodiment includes a cavity resonator 11 in order to flow an alternating current I through the electric wire C in a non-contact manner.

  The cavity resonator 11 can excite a standing wave in a specific microwave frequency band inside. If a part of the electric wire C is allowed to pass through the cavity resonator 11, the electric wire C receives this standing wave. At this time, if the sum of the electric field vectors passing through the electric wire C has a component in the length direction of the electric wire C, an alternating current having a microwave frequency flows through the electric wire C by electromagnetic induction. That is, the standing wave excited in the cavity resonator 11 is converted into an alternating current I flowing through the electric wire C. In the present embodiment, in order to efficiently convert the standing wave into the alternating current I, the standing wave mode excited in the cavity resonator 11 is the TM01 mode.

<TM mode>
FIG. 3 is a diagram showing an electromagnetic field distribution in the cavity resonator 11 in which the standing wave of the TM01 mode is generated. In the figure, the electric field vector is indicated by a solid line, and the magnetic field vector is indicated by a dotted line.
As shown in FIG. 3, a rotating magnetic field around the axis of the cylinder is generated in the cavity resonator 11 in which the standing wave of the TM01 mode is excited, and at the same time, it has a vector in the axial direction of the rotating magnetic field. An electric field is generated. In the standing wave of the TM01 mode, the electric field strength increases as it approaches the center of the rotating magnetic field. Therefore, in the present embodiment, the electric wire C is disposed along the axis of the cylinder that is the center of the rotating magnetic field in the TM01 mode in FIG. Therefore, the conversion efficiency from the microwave to the alternating current I is further improved while using the cavity resonator 11 with low radiation loss and high energy efficiency.

<Configuration of cavity resonator>
Here, a more specific structure of the cavity resonator 11 will be described with reference to FIG. Although FIG. 4 shows a cylindrical cavity resonator as an example, it goes without saying that a rectangular cavity resonator or a spherical cavity resonator can also be used.
As shown in FIG. 4, the cavity resonator 11 includes a metal cylindrical side wall 11 a and end side walls 11 b and 11 c that close both ends in the axial direction. In the end side walls 11b and 11c, openings 11b1 and 11c1 are formed at substantially central portions including a portion through which the cylindrical axis passes, respectively. The end side walls 11b and 11c electromagnetically seal both ends of the cylindrical side wall 11a except for the openings 11b1 and 11c1. The interval L between the end side walls 11b and 11c is L = (λ / 2) × n (n is a natural number) with respect to the wavelength λ of the microwave standing wave to be generated in the cavity resonator 11. It is decided to meet.

<Excitation method>
Microwaves are introduced into the cavity resonator 11 configured as shown in FIG. 4 from a predetermined transmission line. As the predetermined transmission line, a coaxial line, a strip line, a waveguide, a dielectric waveguide, or the like can be used. Further, in order to couple a predetermined transmission line to the cavity resonator 11, loop coupling, probe coupling, hole coupling, slit coupling, or the like can be used. In the present embodiment, for example, a loop antenna is arranged as shown in FIG. 4, and the TM01 mode is excited in the cavity resonator 11 by exciting a rotating magnetic field.
In addition, for example, even if the TE01 mode excited in the rectangular waveguide is introduced into the cylindrical resonant cavity by joining the rectangular waveguide and the cylindrical resonant cavity as shown in FIG. 5, the TM01 mode standing wave is introduced into the cylindrical resonant cavity. Can be excited.

<Microwave radiated from electric wire>
The electric wire C is transported in the length direction by the transport mechanism 30, introduced from the opening 11 b 1 of the cavity resonator 11, and pulled out from the opening 11 c 1. Since this transport path passes through the center of the TM01 mode rotating magnetic field inside the cavity resonator 11 as described above, an AC current traveling in the transport direction is induced in the electric wire C by electromagnetic induction. . That is, since the alternating current I generated in the electric wire C travels in the length direction of the electric wire C, the alternating current I also flows through the electric wire C outside the cavity resonator 11, and the outside of the cavity resonator 11. Microwaves are also radiated from the electric wire C located at.

The microwave radiated from the electric wire C is affected by the covering state of the electric wire C as described above, and the phase around the microwave and the amplitude intensity depend on the covering state at the radiation position. For example, since the microwave radiated from the electric wire C is absorbed when passing through the coating, the radiation intensity is stronger at the portion where the coating is missing than at the portion where the coating is not missing. Also, for example, if the electric wire C is homogeneous, the phase of the transmitted microwave is constant, but the transmission medium is not homogeneous at the portion where the coating of the electric wire C is missing, and the coating is not missing. The way the phase of the microwave is different from the part. That is, if the microwaves radiated from the respective parts of the electric wire C are received and the phase around and the amplitude intensity can be analyzed, information quantifying the covering state can be obtained. In particular, since the alternating current I is a skin current, it is strongly influenced by the state of the adjacent coating as compared to a current that is not a skin current. That is, in the microwave radiated from the electric wire C, the covering state at the portion where the microwave is radiated is reflected deeply.

<Conveyance of electric wires>
By the way, if the electric wire C is conveyed in the length direction at high speed, the electric wire C is vibrated or shaken. When vibration occurs, the distance between the electric wire C and the antenna of the receiving unit 20 also fluctuates, so that the accurate intensity of the microwave cannot be received. Of course, if the antenna is brought into contact with the electric wire C, the fluctuation of the reception intensity due to the spatial fluctuation does not occur. However, if the antenna is brought into contact with the electric wire C so as to suppress vibration and blurring, the covering of the electric wire C may be damaged. Since the time and labor for fixing the electric wire and the inspection device increase every time of inspection, it is desirable to receive the microwave in a non-contact manner in order to simplify the inspection process.

  Of course, since the electric wire C passing through the cavity resonator 11 also vibrates, the electric wire C varies in the degree of coincidence between the center and the axis of the rotating magnetic field, so that the intensity of the alternating current I is also affected by the spatial vibration. Move up and down. In order to eliminate the influence of the fluctuation of the alternating current I, for example, the gain of the receiving unit 20 may be adjusted in synchronization with the intensity of the alternating current I. However, this leads to an increase in the scale of the apparatus. . In order to prevent vibration, for example, it is conceivable to reduce the vibration of the electric wire C by arranging a core blur preventing member such as a guide roller in the conveyance path of the electric wire C. Of course, it is effective in the present embodiment to suppress the spatial vibration of the electric wire C as much as possible with the guide roller, but it is difficult to completely suppress the vibration only by such mechanical anti-vibration measures.

Therefore, in the present embodiment, the information received by the receiving unit 20 and used by the analysis processing unit 40 is not the amplitude information of the microwave but the phase information of the microwave, thereby rejecting the influence of the spatial vibration. To. Since the phase information is not influenced by the reception intensity, the fluctuation of the alternating current I received from the cavity resonator 11 to the electric wire C and the influence of the spatial vibration on the reception intensity of the reception unit 20 are effectively eliminated as described later. Because it can. Note that the phase information to be used in the present embodiment, it is around Rino phase variations.

<Around phase>
FIG. 6 is a graph for explaining about the phase. As shown in the figure, the phase shift Δv of the alternating current I traveling on the electric wire C is equal between AB and other parts . The transmission medium referred to here includes not only the conductor portion through which current actually flows, but also the influence of a coating covering the periphery thereof. In particular, in this embodiment, since the alternating current I is a skin current, the state of the coating greatly affects the current flowing through the conductor. In this sense, the transmission medium includes the coating. Therefore, for example, if there is an abnormality such as a flaw or a pinhole between the points A and B and the transmission medium cannot be regarded as homogeneous, the phase around the phase of the alternating current I changes at that part. The phase rotation Δv during this time becomes not constant as it becomes larger or smaller than other parts. In order to detect such a phase shift Δv, two methods, a method shown in FIG. 7 and a method shown in FIG. 8, can be considered.

<Cancel signal fluctuation due to spatial vibration>
FIG. 7 is a diagram for explaining a method using uniformity of a single section, and FIG. 8 is a diagram for explaining a method using uniformity in the axial direction.
In FIG. 7, a plurality of antennas are arranged around the electric wire C at a constant angle in the vertical cross section of the electric wire C. In this way, by receiving the intensity of the electromagnetic wave radiated by a plurality of antennas arranged equiangularly in one vertical section, the intensity of the electromagnetic wave radiated from the electric wire C in the vertical section is acquired over time. By analyzing the change over time in the intensity of the electromagnetic wave, the change in the phase of the alternating current I flowing through the electric wire C can be tracked. However, with this method, it is difficult to absorb the influence due to the spatial vibration of the electric wire C, and it is difficult to grasp the exact phase change.

On the other hand, in FIG. 8, two antennas offset in the length direction of the electric wire C are disposed adjacent to each other, and the phase around is obtained based on the differential signal. If the distance between adjacent two antennas is sufficiently short, the distance of each antenna with respect to the wire C changes in conjunction. Therefore, in the differential signal of the microwave intensity received by the two antennas, the influence on the reception intensity due to the vibration of the electric wire C is canceled out. That is, it can be seen that the method of FIG. 8 is preferable in order to measure the phase rotation Δv without being affected by the spatial vibration of the electric wire C. Therefore, in the present embodiment, information on the phase is obtained by the latter method. Hereinafter, the latter method is referred to as “adjacent differential”.

<Two antennas are offset in the axial direction>
FIG. 9 is a block diagram illustrating a hardware configuration of the receiving unit 20 and the analysis processing unit 40 of the present embodiment used in the differential between adjacent portions. As shown in the figure, the receiving unit 20 includes two antennas 21a and 21b, BPFs (Band Pass Filters) 22a and 22b, LNAs (Low Noise Amplifiers) 23a and 23b, and BPFs (Band Pass Filters) 24a, 24b and detectors 25a and 25b. The antenna 21a and the antenna 21b are arranged at an equal angle with respect to the axis of the electric wire C and are arranged with a predetermined interval offset in the axial direction of the electric wire C.

The microwave received by the antenna 21a is input to the BPF 22a, and is converted into a microwave MW1 amplified by a predetermined amplification degree while removing unnecessary frequency components and noise components other than the desired microwave frequency by the BPF 22a, the LNA 23a, and the BPF 24a. Is done. The intensity of the microwave MW1 is detected by the detector 25a.
Similarly, the microwave received by the antenna 21b is also input to the BPF 22b, and the microwave amplified by a predetermined amplification degree while removing unnecessary frequency components and noise components other than the desired microwave frequency by the BPF 22b, the LBA 23b, and the BPF 24b. MW2. The intensity of the microwave NW2 is detected by the detector 25b.
The detected microwaves MW1 and MW2 are input to the analysis processing unit 40.

In this embodiment, the differential between adjacent antennas is performed by two antennas. However, a modification such as processing differential signals between the antennas by offsetting three or more antennas at predetermined intervals in the axial direction. Examples are naturally included in the scope of the present invention. If the number of antennas is increased in the axial direction in this way, the observation area in the axial direction is expanded, so that the conveying speed of the electric wire C can be increased.
Further, as shown in FIG. 10, the same number of antennas are arranged at equal angles in each of adjacent vertical sections offset by a predetermined distance, and each pair of antennas adjacent in the axial direction is subjected to inter-adjacent differential. Naturally, a modification for detecting the rotation of the phase is also included in the scope of the present invention. When the antenna is arranged as shown in the figure, since the antenna is arranged in an axial symmetry, the electric field distribution shown later is also in the axial symmetry, and the measurement accuracy is improved. The variation around the phase is measured for each set of antenna is also improved measurement accuracy around the phase by averaging them.

<Place antenna on belly of standing wave>
FIG. 11 is a diagram conceptually showing the electric field distribution of electromagnetic waves radiated by the alternating current I and the positional relationship between the antennas 21a and 21b. In the upper part of the figure, a standing wave of the electric field intensity distribution generated by the alternating current I when the covering state of the electric wire C is normal is shown. The standing wave of the electric field intensity distribution generated by the alternating current I at a certain time is shown. As shown in the upper diagram of FIG. 11, when the antennas 21a and 21b are arranged at positions corresponding to antinodes of standing waves when the covering is normal, fluctuations in the electric field intensity can be detected with the highest sensitivity. This is because the S / N ratio is improved because the electric field strength is strongest in the antinode portion of the standing wave. In addition, since the differential signal is minimum at the antinode, it is possible to easily detect an abnormality in the covering depending on whether the differential signal has risen to a predetermined amount or more.

  Since there are two antennas in the case of differential between adjacent areas, it is conceivable to arrange one of the antennas so as to match the peak of the standing wave. The selection of which antenna to match with the belly should be selected so that the differential signal appears more greatly when the rotation around the phase fluctuates. In the example shown in FIG. 11, since there is a flaw around the phase when there is a flaw, the left antenna should be substantially coincident with the center of the belly. This is because the detection sensitivity is improved because the differential signal changes significantly when the phase is rotated. Of course, even when the antenna is arranged as shown in FIG. 7, if the antenna is arranged so as to coincide with the antinode of the standing wave, the detection sensitivity is improved.

<Analysis processing unit>
In FIG. 11, the analysis processing unit 40 includes amplifiers 42a and 42b, a differential amplifier 43, a differential amplifier 44, a variable gain amplifier 45, and a comparator 46. The microwave MW1 and the microwave MW2 are amplified by the amplifier 42a and the amplifier 42b, respectively. The amplified microwave MW1 is input to the non-inverting input terminal of the differential amplifier 43. Further, the amplified microwave MW2 is input to the inverting input terminal of the differential amplifier 43. As a result, the differential amplifier 43 outputs a differential signal Def1 of the microwaves MW1 and MW2.

  In the differential amplifier 44, both the microwave MW1 and the microwave MW2 are input to the inverting input terminal of the differential amplifier 44, and a predetermined comparison voltage (fixed value) is input to the non-inverting input terminal. . As a result, the differential amplifier 44 outputs a differential signal Def2 having an average value of the microwaves MW1 and MW2 and a predetermined comparison voltage. The differential signal Def2 is input to the variable gain amplifier 45 as a gain control signal. That is, the variable gain amplifier 45 adjusts the gain of the differential signal Def1 to a signal level that would be obtained when the microwaves MW1 and MW2 are normalized to a constant value.

  The differential signal Def1 gain-adjusted by the variable gain amplifier 45 is input to the inverting amplification terminal of the comparator 46 and compared with a predetermined voltage (threshold value) input to the non-inverting input terminal of the comparator 46. The predetermined threshold value is a reference voltage for determining whether or not there is an abnormality in the covering, and is set by experimental calculation in advance. As a result, the comparator 46 outputs a predetermined voltage when the differential signal Def is larger than a predetermined threshold, and does not output a predetermined voltage when the differential signal Def is smaller than the predetermined threshold. Therefore, the operator can grasp the abnormality of the covering of the electric wire C based on the presence or absence of the output voltage of the comparator 46.

  In the above-described embodiment, the analysis processing unit 40 is configured by an analog circuit. However, the microwaves MW1 and MW2 output from the reception unit 20 are input to a predetermined program execution environment, converted into digital signals, and the above-described embodiments. Analysis processing similar to that of the analog circuit may be executed programmatically. As a program execution environment, at least an A / D conversion unit that receives a differential signal Def1 and A / D converts the differential signal Def1, a ROM (Read Only Memory) that stores an analysis processing program, and an analysis processing program from the ROM as appropriate It is only necessary to have a CPU (Central Processing Unit) that reads and executes the data and a RAM (Random Access Memory) that is used as a work area of the CPU.

<Effect of differential between adjacent>
By detecting the progress of phase per predetermined length of the wire C on the basis of the differential signal between the adjacent antennas as described above, around the phase while offsetting changes in signal strength due to the amplitude of the electric wire C Can be detected.
<Miniaturization of phase shift>
The offset interval between the antennas is preferably the shortest distance that can avoid physical interference between the antennas. If the offset interval between the antennas is set to a short distance, even if the electric wire C vibrates, the interval between the antenna and the electric wire C changes in the same way, so that the influence of spatial vibration on the microwave intensity received by each antenna is the same. To change. Therefore, the differential signal Def1 can accurately cancel the fluctuations in the reception intensity caused by the spatial vibration. More specifically, for example, in the case of a microwave, 1/10 or less of the wavelength is desirable, and when using a 5.8 GHz microwave having a wavelength of 51.7 mm, the distance between the antennas is 5.17 mm or less. Good.

<Frequency band to be used>
The microwave excited in the cavity resonator 11 of the present embodiment is particularly preferably an ISM band (Industry-Science-Medical Band) microwave. This is because the use in the ISM band has a small effect on existing communications, and is relatively lenient with respect to electromagnetic interference (Electro Magnetic Interference) and the like. More specifically, the 2.4 GHz band (2400-2500 MHz), 5.8 GHz band (5725-5875 MHz), 10.8 GHz, which are defined by the ITU (International Telecommunication Union) in the microwave band. It is preferable to use a band, 24 GHz band (24-24.25 GHz).

<Board with antenna and analysis unit mounted>
The receiving unit 20 and the analysis processing unit 40 described above are easy to handle when arranged on one substrate as shown in FIG. As shown in the figure, a hole penetrating from the front to the back is formed in the substrate P, and the electric wire C is passed through this hole. Around the hole, an antenna is arranged at an equiangular angle around a point through which the electric wire C passes.
A predetermined range around the hole is a high frequency area, and the outside of the high frequency area is a data processing area. The boundary between both areas is provided outside the distance at which the electromagnetic wave intensity radiated from the electric wire C is attenuated to a predetermined intensity. The predetermined strength mentioned here is determined so that each element arranged in the data processing area does not cause malfunction and is sufficiently lower than the signal strength transmitted through the signal transmission line in the data processing area. it can. The elements 21 to 44 of the receiving unit 20 are arranged in the high frequency area thus determined, and the elements 46 to 49 of the analysis processing unit 40 and the CPU, RAM, and ROM for performing data processing are arranged in the data processing area. An element having a high possibility of malfunctioning due to a high-frequency signal is arranged.
When the receiving unit 20 and the analysis processing unit 40 are arranged on the substrate P as described above, the equiangular arrangement of the antenna is very easy, and the data processing unit, the antenna, and the detector can be handled integrally. Workability such as assembly is improved.

<Shielding plate>
Furthermore, it is preferable to arrange a shielding plate between the excitation unit 10 and the receiving unit 20 because the influence of the leakage wave from the opening of the cavity resonator is reduced. FIG. 13 is a diagram showing an instantaneous value distribution of the electric field formed along the electric wire C. FIG. In the same figure, the figure shown above is the figure which showed electric field distribution when not arrange | positioning a shielding board, and the figure shown below has arrange | positioned the shielding board made from aluminum between the excitation part 10 and the receiving part 20. FIG. It is the figure which showed the electric field distribution in the case.

  The electric wire C used for the measurement in FIG. 13 is a copper wire of φ = 1 mm coated with PTFE with a thickness of 0.1 mm, and the shielding plate has an opening of φ = 10 mm for allowing the electric wire C to pass through. Yes. When comparing the electric field distribution with and without the shielding plate, the axial symmetry of the electric field is not established without the shielding plate, but when the shielding plate is placed, the part shielded from the cavity resonator by the shielding plate Shows that the electric field is axisymmetric.

<Example: Sensitivity>
In order to test the detection sensitivity of the configuration described above, the detection sensitivity test of the covering state was performed with the experimental configuration shown in FIG. 14, and the result shown in FIG. 15 was obtained. In the test configuration shown in FIG. 14, the electric wire C is a copper wire of φ = 1 mm coated with 0.1 mm of PTFE, and a coating missing portion of 0.5 mm is formed in the coating. Further, two antennas separated by 2.5 mm in the axial direction of the electric wire C are arranged at a position 5 mm from the electric wire C. The cavity resonator 11 oscillates a 5.8 GHz TM01 mode microwave.

  FIG. 15 is a plot of the electric field strength received by each antenna while sweeping the detection frequency from 0 GHz to 8 GHz with the antennas aligned with the unscratched part and the scratched part in the experimental configuration shown in FIG. It is. From the figure, it can be read that the difference in the reception intensity of each antenna in the vicinity of 5.8 GHz is larger by 0.3 to 0.6 dB when there is a flaw than when there is no flaw. It can also be read that the electric field measured at a position 5 mm away from the electric wire C is -47 dB. Therefore, it can be seen that the lack of coating can be detected at a practical level based on the electric field intensity radiated from the electric wire C.

(2) Cover inspection processing:
Here, a covering inspection process when the circuit processing performed by the analysis processing unit 40 described above is realized in a program execution environment will be described. In the following description, a program execution environment including, for example, a CPU, a RAM, and a ROM will be referred to as a control unit 50. The inspection apparatus 100 displays a result of the covering inspection process, an operator instructs the inspection apparatus 100 to start the inspection, displays the result of the covering inspection process, and sets a display method of the result. It has an operation input unit. The display and the operation input unit are also provided when the analysis processing unit 40 is configured by a circuit as described above.

  FIG. 16 is a flowchart of the covering inspection process. As a preparation before executing this process, an operator who executes the inspection apparatus holds one end of the electric wire C, and the electric wire C passes through the cylindrical axis of the cavity resonator 11 and exits from the opening 11b1 to the opening 11c1. For example, one end of the transport mechanism 30 is set. When the user starts the inspection process by operating the inspection apparatus 100, first, a TM01 mode microwave standing wave is excited in the cavity resonator 11, and then the transport mechanism winds the electric wire C by a winding mechanism or the like. Thus, the conveyance of the electric wire C is started. Then, the analysis processing unit 40 starts processing to acquire the differential signal Def1 from the receiving unit 20. The preparation up to this point is the same when the analysis processing unit 40 is realized by a circuit as described above.

  When the process is started, in step S100 (hereinafter, “step” is omitted), the control unit 50 acquires digital signals of the microwaves MW1 and MW2 from the A / D conversion unit. Note that data acquisition in S100 is automatically executed at predetermined time intervals. The predetermined time here is determined by the relationship between the conveyance speed of the electric wire C and the size of an abnormal part (for example, a scratch) that is supposed to be formed on the electric wire C, and the electric wire C within the predetermined time. Is determined so as to be equal to or smaller than the size of an abnormal part (for example, a wound) assumed to be formed on the electric wire C. By appropriately setting the predetermined time, the inspection apparatus 100 has a time resolution sufficient to inspect the electric wire C without leakage.

  In addition, data acquisition and the process of following S105-S120 may be performed in parallel, and the process of S105-S120 is performed with respect to each data acquired after the data acquisition of S100 was completed in the full length of the electric wire C. You may perform in order. Further, if the processes of S105 to S120 are completed within a predetermined time, the processes of S100 to S120 may be repeatedly executed at predetermined time intervals.

  In S105, the control unit 50 calculates a difference ΔMW between the microwave MW1 and the microwave MW2. This difference ΔMW corresponds to the differential signal Def1 in the circuit described above. In S105, the control unit 50 may amplify the signal intensity of the differential signal Def1 by a predetermined ratio or perform noise removal processing.

  In S110, the control unit 50 adjusts the gain of the difference ΔMW. For example, the control unit 50 acquires an average value of the microwaves MW1 and MW2 as the index value I, and calculates a ratio S / I between the index value I and a predetermined reference value S. Then, the ratio S / I is multiplied by the difference ΔMW. Then, when the average value of the microwaves MW1 and MW2 is normalized to the reference value S, the difference ΔMW is gain-adjusted to a difference value that would be obtained from the normalized microwaves MW1 and MW2. Is done. Of course, as the index value I at this time, the average value of the microwave MW1 and the microwave MW2 may be increased or decreased by a predetermined ratio, or may be either the microwave MW1 or the microwave MW2. .

  In S115, the control unit 50 determines the magnitude relationship between the difference ΔMW and a predetermined threshold value. This threshold value is a reference value for determining whether or not there is an abnormality in the covering, and is experimentally determined in advance. When the difference ΔMW is larger than a predetermined threshold as a result of the comparison, the control unit 50 determines that there is an abnormality in the covering, stores that in the RAM together with information indicating the timing at which the difference ΔMW is acquired, When ΔMW is smaller than a predetermined threshold, it is determined that there is no abnormality, and information indicating the timing at which the difference ΔMW is acquired is stored in the RAM. Of course, either one of the presence / absence of abnormality may be indicated by not storing anything in the RAM.

In S120, the control unit 50 determines whether or not the inspection is completed over the entire length of the electric wire C. If not completed, the process returns to S100 and the processes of S105 to S115 are performed on the next difference ΔMW to determine whether there is an abnormality. On the other hand, if the inspection has been completed for the entire length of the electric wire C, the process proceeds to S125.
In S125, the control unit 50 displays the presence / absence of the abnormal part and the part of the abnormal part on the display. The location of the abnormal part can be calculated based on the conveyance speed of the electric wire C and the detected timing of the abnormal part. Of course, if the inspection result is displayed in real time, the conveyance of the electric wire C may be stopped when the abnormality is detected so that the operator can check the location where the abnormality is determined.

(3) Modification 1:
In the above-described embodiment, the electric wire C that moves at high speed in the axial direction as an inspection target has been described as an example. Therefore, a coating abnormality is detected based on a change in the phase around detected by the differential between adjacent portions . However, when the present invention is applied to a static inspection object in which spatial vibration does not occur, the above-described adjacent-to-adjacent differential can naturally be used, but a method using amplitude information can also be used, and an antenna in a vertical section can be used. It is also possible to use a method of detecting the phase by arranging them at the same angle.
Therefore, as an example of detecting an abnormality in the coating using amplitude information, a fusion test of a hemostatic balloon will be described below.

FIG. 17 is a block diagram showing a configuration of an inspection apparatus 200 for inspecting fusion of a hemostatic balloon. In the figure, the inspection apparatus 200 includes an excitation unit 210, a reception unit 220, a rotation drive unit 230, and an analysis processing unit 240. The excitation unit 210 is the same as that in the above-described embodiment, and the reception unit 220 includes one antenna and the BPF or LNA that the reception unit 20 has.
Note that one end of the hemostasis balloon is fused to the outer periphery of the guide tube, and the hemostasis balloon itself is disposed outside the excitation unit 210. In the guide tube, for example, a stainless steel wire W is inserted through the center of the tube, and a part of the wire W is disposed inside the excitation unit 220. In the same manner as the electric wire C described above, an alternating current I is passed through the wire W by the excitation unit 210.

  The receiving unit 220 includes a uniaxial mechanical turning mechanism as shown in FIG. 18, and can be retracted in the radial direction to correspond to the size of the balloon portion of the hemostatic balloon. The reason why the number of antennas of the receiving unit 220 in this modification is one is that there is no spatial vibration in the hemostasis balloon, and the microwave radiation intensity can be accurately detected with one antenna. Of course, multiple antennas may be used. For example, if a plurality of antennas are equiangularly arranged within the vertical cross section of the core wire of the hemostatic balloon, the entire circumference inspection of the fusion site can be completed without rotating the guide tube in the inspection process described later.

The rotation drive unit 230 can be configured by a reverse rotation mechanism using a rack and pinion, for example, as shown in FIG. In FIG. 19, the holding part 231 can hold the conductor wire, and when the pinion is rotated, the rack A and the rack B are transported in the opposite directions in FIG. 19 while maintaining the parallel positional relationship, and are held by the holding part 231. The formed conductor wire is rotated in the same direction as the rotation direction of the pinion.
In addition, the rotation drive unit 230 holds the wire W so that the spatial coordinates of the wire W are stabilized by supporting both ends of the wire W, and the wire W and the hemostasis balloon by a core shake prevention mechanism such as a guide wheel. The spatial coordinates of are fixed. As a result, the distance between the antenna of the receiving unit 220 and the fusion site of the hemostatic balloon is constant and does not vibrate as in the above-described embodiment.

  Here, with reference to FIG. 20, the abnormality which may arise in the fusion | fusion part of the hemostatic balloon and a guide tube is demonstrated concretely. FIG. 20 is an enlarged cross-sectional view of a main part showing a section where a hemostasis balloon and a guide tube are fused. As shown in the figure, a guide tube covers a wire W at the center, and one end of a hemostatic balloon is fused to the outer periphery of the guide tube. At this fusion site, there is a possibility that foreign matter such as air bubbles enters between the guide tube and the hemostasis balloon, which is a poor fusion of the hemostasis balloon.

  The presence or absence of poor fusion can be determined by the intensity of a certain intensity of microwave radiated from the wire W. This is because an air layer is present in a portion where there is a poor fusion, so that the boundary where materials having different dielectric constants are in contact with each other increases and the attenuation of radiation intensity increases. For example, if the fusion is complete, the boundary is only formed between the guide tube and the hemostatic balloon, but at the site with air bubbles, the boundary between the guide tube and the gas phase Two boundaries are formed between the phase and the hemostatic balloon. Accordingly, the electric field intensity at a constant distance from the core wire is uniform and has a substantially circular distribution if the fusion is uniform, but the circularity is lost in the portion containing bubbles. As in the case where the alternating current I is passed through the electric wire C described above, the instantaneous value of the electric field distribution as shown in FIG.

  In this modification, it is sufficient to insert only the wire W into the excitation unit 210, but a guide tube may be inserted into the excitation unit 210. Further, a guard sleeve for preventing contact is required between the inserted wire W and the excitation unit 210. Further, since the hemostatic balloon is a medical device, it is necessary to attach a bactericidal hood to the table on which the inspection apparatus 200 is placed.

  With the above configuration, the control unit 250 executes the inspection process shown in FIG. FIG. 22 is a flowchart of the inspection process. In addition, the control part 250 with which the test | inspection apparatus 200 of this modification is provided is also a program execution environment provided with CPU, RAM, and ROM similarly to the control part 50 of embodiment. In performing the inspection process, the operator sets a hemostatic balloon having a wire W core wire at the center thereof in the inspection apparatus 200. At this time, the position is adjusted so that the antenna comes close to the fusion site between the hemostatic balloon and the guide tube. Next, the operator holds the guide tube on the holding unit 231 of the rotation driving unit 230 and places the receiving unit 220 at the detection position. At this time, the positions of the antenna and the fusion site are further adjusted.

  As shown in FIG. 22, in S200, the control unit 250 rotates the pinion of the rotation driving unit 230 by a predetermined amount to rotate the guide tube by a predetermined angle. In other words, in S200, the fusion site facing the antenna is changed.

In S205, the control unit 250 acquires the electric field strength from the receiving unit 220, and stores the electric field strength in the RAM in association with the angle set in S200.
In S210, control unit 250 determines whether or not the total rotation amount rotated in S200 has reached 360 °. If the rotation of 360 ° has been completed, the process proceeds to S215. If the total rotation amount is less than 360 °, the process returns to S200 to perform the processes after S200.

  In S215, the control unit 250 displays the inspection result on the display. For example, for each measurement position in the axial direction, a graph plotting the electric field strength distribution with respect to the measurement angle is displayed, or a portion where the difference between the electric field strength at the adjacent measurement angle is a predetermined value or more is determined as abnormal, Notify the site. Of course, if it is possible to determine whether the hemostasis balloon is acceptable or not at the medical site, it can be used as a guideline for whether or not the balloon can be used.

  In the first modification, the inspection of the balloon tube and the guide tube covering the wire W has been described as an example. However, the first modification can also be used for the inspection of the diamond covering of the thin piano wire. The small-diameter piano wire referred to here is obtained by sintering diamond powder on the surface of the piano wire, and is used for silicon cutting (die cutting) for semiconductors. The condition of diamond baking on this piano wire affects the processing performance of silicon. For example, if a normal wire is applied to a piano wire with a missing diamond coating, the piano wire will be in direct contact with the silicon and will break. Therefore, the thickness of the diamond coating can be inspected by applying the inspection of the first modification to the thin piano wire.

  Further, in the above-described first modification, the antenna of the receiving unit is moved or a plurality of antennas are arranged in the circumferential direction or the axial direction of the electric wire, and acquired as variation data obtained by measuring the electric field strength along a predetermined direction. However, such variable data is not essential. For example, if the electric field strength to be measured in a normal covering state is known in advance, the electric field strength is determined to be normal if the electric field strength is within a predetermined range based on the electric field strength, and the electric field strength is within the predetermined range. If it is outside, it can be determined that the coating is abnormal.

(4) Modification 2:
<Power / frequency control>
In addition to the embodiments and modifications described above, if the power and frequency of the microwaves oscillated by the excitation unit 10 and the excitation unit 210 are controlled to be stable, the intensity of electromagnetic waves radiated from the electric wires C and wires W can be increased. Stabilize. In the embodiment, since a differential signal is used, sufficient accuracy can be obtained without this control, but amplitude information is acquired with one antenna as in the case of a coating inspection of a hemostatic balloon according to a modified example. In this case, the accuracy is greatly improved by performing this control.

(5) Modification 3:
In the embodiment described above, the antenna is used as the antenna of the receiving unit as an example. However, the means for measuring the electric field strength of the electromagnetic wave radiated to the space is not limited to this.
FIG. 23 shows another example of a receiving unit that measures electromagnetic waves. This figure shows an electric field sensor using an electro-optic crystal (EO crystal) whose refractive index changes when an electric field is applied. The electro-optic effect (EO effect) includes a Pockels effect and a Kerr effect, but an EO crystal having a Pockels effect is often used for an electric field sensor using an EO crystal. This is because the amount of change in the refractive index is linearly proportional to the electric field strength, so that calibration is easy.

<Receiver configuration>
In FIG. 23, the receiving unit 320 includes an electric field sensor 321 and a polarization processing unit 322. The electric field sensor 321 includes a reflective film 321a formed of a dielectric, an EO crystal 321b, a collimator lens 321c, a ferrule 321d, and an optical fiber 321e in order from the tip. The rear end of the optical fiber 321f is connected to an optical fiber connector, and is connected to the polarization processing unit 322 via the optical fiber connector. Note that since an EO crystal of 1 mm square, for example, can be used, the electric field sensor 321 can be made smaller than an electric field sensor (a length of several centimeters to several tens of centimeters) using a conventional dipole antenna.

<Movement of light in electric field sensor>
In the receiving unit 320, the tip of the optical fiber 321e is connected perpendicular to the EO crystal 321b. In the EO crystal 321b, a light incident surface that is a plane on which light is incident from the optical fiber 321e and a reflective surface that is a plane on which the reflective film 321a is formed are formed in parallel to each other. The reflective film 321a reflects light that has reached the reflective surface from the inside of the EO crystal 321b. Accordingly, the incident light incident from the optical fiber 321e is perpendicularly incident on the incident surface, reaches the reflection surface as it is, is reflected vertically by the reflection surface, and is incident again on the optical fiber 321e.

  The reflected light incident on the optical fiber 321e maintains the same polarization state as the incident light when the EO crystal is not irradiated with electromagnetic waves. This is because the refractive index of the EO crystal 321b has not changed. On the other hand, since the refractive index changes when the EO crystal is irradiated with electromagnetic waves, the reflected light incident on the optical fiber 321e changes to a polarization state different from the incident light. The polarization processing unit 322 converts a change in the polarization state into a change in light intensity using the analyzer 322a and the like, and outputs a signal corresponding to the electric field strength of the electromagnetic wave by converting the light intensity conversion into an electric signal. If the signal according to the electric field strength obtained in this way is analyzed by the analysis processing unit of the above-described embodiment or modification, the covering state can be inspected.

In addition, the phase change occurs in the light when transmitting the optical fiber, but the same phase change occurs in both the incident light that goes up the optical fiber and the reflected light that goes down the optical fiber, so the phase change cancels up and down, Phase change in the optical fiber can be made zero.
In addition, the electric field sensor 321 of the present embodiment can accurately capture the state of the original electromagnetic wave to be measured. The EO crystal 321b, the collimator lens 321c, and the ferrule 321b do not contain a metal, and the reflection film 321a is formed of a dielectric, and can transmit a signal to the polarization processing unit 322 through the optical fiber 321e. This is because the electromagnetic waves that are radiated are not disturbed and electrical coupling does not occur even if they are arranged in the vicinity of the measurement object.

(6) Summary:
According to the embodiment described above, in the inspection apparatus 100 for inspecting the presence or absence of a dielectric flaw or a pinhole in the electric wire C covered with the dielectric, the microwave resonator 11 generates the TM01 mode microwave standing wave. When excited, the electric wire C is allowed to pass through the center of the rotating magnetic field in the TM01 mode, thereby passing an alternating current I having a microwave frequency through the electric wire C. And the microwave radiated | emitted from the electric wire C which continues from the inside of the cavity resonator 11 to the exterior is received, and two antennas offset in the length direction of the electric wire C are made with respect to the axis of the electric wire C, etc. Arranged adjacent to the angle, the phase around the alternating current I is obtained based on the differential signal. A part that is not constant around the phase is detected, and it is determined that there is an abnormality in the covering of the part. By inspecting the inspection of the electric wire C by the above method, the covering inspection of the covering wire material can be executed more easily and faster than the conventional method.

  Note that the present invention is not limited to the above-described embodiments and modifications, and the structures disclosed in the above-described embodiments and modifications are mutually replaced, the combinations are changed, the known technique, and the above-described implementations. Configurations in which the configurations disclosed in the embodiments and modifications are mutually replaced or the combinations are changed are also included.

DESCRIPTION OF SYMBOLS 10 ... Excitation part, 11 ... Cavity resonator, 11a ... Cylindrical side wall, 11b ... End side wall, 11c ... End side wall, 11b1 ... Opening, 11c1 ... Opening, 20 ... Reception part, 21a ... Antenna, 21b ... Antenna 22a ... BPF, 22b ... BPF, 23a ... LNA, 23b ... LNA, 24a ... BPF, 24b ... BPF, 25a ... detector, 25b ... detector, 30 ... carrier mechanism, 40 ... analysis processing unit, 43 ... differential Amplifier 44 ... Differential amplifier 45 ... Variable gain amplifier 46 ... Comparator 42a ... Amplifier 42b ... Amplifier 100 ... Inspection device 200 ... Inspection device 210 ... Excitation unit 220 ... Reception unit 230 ... Rotation Drive unit, 231 ... holding unit, 240 ... analysis processing unit, 320 ... receiving unit, 321 ... electric field sensor, 321a ... reflective film, 321b ... EO crystal, 321c ... collimator Lens, 321d ... ferrule, 321e ... optical fiber, 322 ... polarization processing unit, 322a ... analyzer, C ... wire, I ... alternating current, P ... substrate, W ... wire

Claims (12)

An inspection device for inspecting a state of a dielectric covering a conductive wire,
An excitation unit that excites a standing wave of an electromagnetic wave of a predetermined frequency in a cavity resonator in a TM01 mode, and causes an alternating current of the predetermined frequency to flow through the conductive wire passing through the cavity resonator by electromagnetic induction;
A receiving unit that receives the electromagnetic wave of the predetermined frequency that is radiated from the conductive line by an alternating current flowing through the conductive line, and radiated through the dielectric;
Inspection apparatus characterized by comprising a determining section for determining a state of the dielectric based on at least one of an amplitude intensity and phase around the electromagnetic wave which the receiving unit receives. The conductive wire has moved in the length direction of the conductive wire,
The inspection apparatus according to claim 1, wherein the determination unit determines the state of the dielectric based on a fluctuation around the phase of the electromagnetic wave received by the reception unit. The receiving unit receives the electromagnetic wave while scanning the conductive wire in a predetermined direction,
The inspection apparatus according to claim 1, wherein the determination unit determines the state of the dielectric based on at least one change in amplitude intensity and phase around the electromagnetic wave received by the reception unit.   The inspection apparatus according to any one of claims 1 to 3, wherein the conductive wire is disposed along substantially the center of the rotating magnetic field in the TM01 mode.   The said excitation part flows the alternating current of a microwave frequency to the said conductive wire by exciting the standing wave of a microwave frequency to the said cavity resonator, The any one of Claims 1-4 characterized by the above-mentioned. Inspection equipment.   The receiving unit includes at least two electric field sensors that are equiangular with respect to the axis of the conductive wire and are offset in the length direction of the conductive wire, and are based on a differential signal between the electric field sensors. The inspection apparatus according to claim 1, wherein the circumference of the phase is detected.   The inspection apparatus according to claim 6, wherein the distance between the electric field sensors is a shortest distance at which interference between the electric field sensors can be avoided. The alternating current flowing through the conductive wire is a standing wave,
The inspection apparatus according to claim 6 or 7, wherein at least one of the electric field sensors is disposed close to an antinode of the standing wave formed when the dielectric is in a reference state.   The determination unit according to any one of claims 1 to 8, wherein the determination unit determines that there is an abnormality in the covering with respect to a portion where the variation of the differential signal or amplitude intensity detected by the reception unit exceeds a predetermined value. The inspection device described.   The inspection according to any one of claims 1 to 9, wherein the excitation unit and the reception unit are configured separately, and a shielding plate made of a conductor is disposed between the excitation unit and the reception unit. apparatus. An inspection method for inspecting a state of a dielectric covering a conductive wire,
Exciting a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode, and causing an alternating current of the predetermined frequency to flow through the conductive wire penetrating the cavity resonator by electromagnetic induction;
A receiving step of receiving an electromagnetic wave of the predetermined frequency which is radiated from the conductive line by an alternating current flowing through the conductive line and radiated through the dielectric;
An inspection method comprising: a determination step of determining the state of the dielectric based on at least one of amplitude intensity and phase around the electromagnetic wave received in the reception step. An inspection program for causing a computer to perform a function of inspecting a state of a dielectric covering a conductive wire,
An excitation function of exciting a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode and causing an alternating current of the predetermined frequency to flow through the conductive wire penetrating the cavity resonator by electromagnetic induction;
A receiving function for receiving the electromagnetic wave of the predetermined frequency , which is an electromagnetic wave radiated from the conductive line by an alternating current flowing through the conductive line, and radiated through the dielectric;
An inspection program for causing a computer to realize a determination function for determining the state of the dielectric based on at least one of the amplitude intensity and the phase around the electromagnetic wave received by the reception function.