JP5506607B2 - Shield member abnormality detection method and shield member abnormality detection device - Google Patents

Description

  The present invention relates to a shield member abnormality detection method and apparatus, and more particularly to a conductive core wire, an internal insulator covering the core wire, a shield member wound around an outer periphery of the internal insulator, and the shield The present invention relates to a shield member abnormality detection method and apparatus for detecting abnormality of the shield member in an electric wire having an external insulator covering the member.

  A CV cable 10 for supplying high voltage power as shown in FIG. 5 is known as the above-described electric wire. As shown in the figure, the CV cable 10 includes a core wire 11, an insulator 12 as an internal insulator, a copper tape 13 as a shield member, and a sheath 14 as an external insulator.

  The core wire 11 is made of a conductive conductor. The insulator 12 is made of crosslinked polyethylene or the like and covers the core wire 11. The copper tape 13 is provided to prevent noise from entering from the outside. The copper tape 13 is provided in a tape shape and is wound around the outer periphery of the insulator 12. The sheath 14 is made of polyethylene or the like and covers the copper tape 13.

  In the CV cable 10 described above, the copper tape 13 may be displaced due to the laying condition or aging. Due to this deviation, an abnormal portion that is not covered by the copper tape 13 may occur in the core wire 11 depending on the location. Thereby, there existed a problem that the performance quality of the CV cable 10 deteriorated.

  Therefore, in order to solve the above-described problem, an abnormality detection apparatus as shown in FIG. 5 has been proposed (Patent Document 1). As shown in the figure, the abnormality detection device 20 includes a transmission / reception antenna AT2, an oscillation circuit 21 that outputs a traveling wave W1 to the transmission / reception antenna AT2, a circulator 22 that detects a reflected wave W2 from the transmission / reception antenna AT2, The reception circuit 23 that receives the reflected wave W2, the determination circuit 24 that determines the displacement (detection) of the copper tape 13 based on the level of the reflected wave W2 received by the reception circuit 23, and the determination circuit 24 allows the copper tape 13 to be detected. And an alarm circuit 25 for generating an alarm to that effect when it is determined that there is a deviation.

  Next, the principle of abnormality detection of the abnormality detection device 20 will be described before describing the detailed configuration of the abnormality detection device 20 described above. In general, when the transmission / reception antenna AT2 is close to a metal body, the antenna impedance decreases, and impedance matching between the transmission / reception antenna AT2 and the feeding path cannot be achieved, and the antenna reflected wave W22 at the transmission / reception antenna AT2 increases. Therefore, when the normal part with the copper tape 13 is scanned with the transmission / reception antenna AT2, the transmission / reception antenna AT2 and the copper tape 13 which is a metal body are close to each other, and the antenna reflected wave W22 at the transmission / reception antenna AT2 becomes large.

  On the other hand, when the abnormal portion where the deviation occurs in the copper tape 13 is scanned by the transmission / reception antenna AT2, the transmission / reception antenna AT2 and the copper tape 13 do not come close to each other, and the antenna reflected wave W22 at the transmission / reception antenna AT2 decreases. . The abnormality detection device 20 detects the deviation of the copper tape 13 with one transmission / reception antenna AT2 by viewing the antenna reflected wave W22 from the transmission / reception antenna AT2. Actually, the abnormality detection device 20 detects the deviation of the copper tape 13 based on a reflected wave W2 that is an interference wave between the antenna reflected wave W22 and a cable reflected wave W21 described later.

  Returning to the configuration of the abnormality detection device 20, the transmission / reception antenna AT2 is attached to the CV cable 10 so as to be scanned along the CV cable 10 by an attachment portion (not shown). In addition, when the transmission / reception antenna AT2 is attached to the CV cable 10 by the attachment portion, the antenna impedance changes between when the normal portion with the copper tape 13 is scanned and when the abnormal portion without the copper tape 13 is scanned. Are disposed close to the CV cable 10.

  The circulator 22 includes a port P1 to which the traveling wave W1 from the oscillation circuit 21 is input, a port P2 to which the traveling wave W1 input from the port P1 is output, and a reflected wave of the transmission / reception antenna AT2 input to the port P2. And a port P3 from which W2 is output.

  In the circulator 22, when the traveling wave W1 from the oscillation circuit 21 is input to the port P1, the traveling wave W1 input to the port P1 is output from the port P2 and transmitted to the transmission / reception antenna AT2. A part of the traveling wave W1 reaching the transmission / reception antenna AT2 is radiated as a transmission radio wave W3 from the transmission / reception antenna AT2. The radiated transmission radio wave W3 is reflected by the core wire 11 or the copper tape 13 of the CV cable 10 and received by the transmission / reception antenna AT2 again as the cable reflected wave W21. The cable reflected wave W21 received by the transmission / reception antenna AT2 is input to the port P2.

  Further, the remaining part of the traveling wave W1 reaching the transmission / reception antenna AT2 is reflected by the transmission / reception antenna AT2. The antenna reflected wave W22 reflected by the transmission / reception antenna AT2 is input to the port P2. That is, an interference wave between the cable reflected wave W21 and the antenna reflected wave W22 is input to the port P2 as the reflected wave W2. FIG. 6 shows the result of measuring the level of the reflected wave W2 when the oscillation frequency of the oscillation circuit 21 is changed in the abnormality detection device 20 having the above-described configuration.

  However, in the method of scanning one transmission / reception antenna AT2 along the CV cable 10 as described above, the following problems occur. That is, in the conventional abnormality detection method, the impedance change of the transmission / reception antenna AT due to the deviation of the copper tape 13, that is, the deviation detection is performed at the resonance portion due to the reflection characteristic of the transmission / reception antenna AT, so that the measurement frequency range is narrow. there were. That is, as shown in FIG. 6, the fluctuation amount of the reflected wave W2 due to the presence or absence of the copper tape 13 can be increased only in a narrow area of 5.71 to 5.72 GHz near the resonance frequency. There was a problem that the shift could not be detected.

JP 2009-281850 A

  Accordingly, an object of the present invention is to provide a shield member abnormality detection method and apparatus for detecting a shield member abnormality in a wide band.

  The invention according to claim 1 for solving the above-described problem includes a conductive core wire, an internal insulator covering the core wire, a shield member wound around an outer periphery of the internal insulator, and the shield member. In a shield member abnormality detection method for detecting an abnormality of the shield member in an electric wire having an external insulator to be coated, a normal part where the shield member is scanned is scanned with a transmission antenna and a reception antenna provided separately from each other. And a step of arranging the antennas in proximity to the electric wire and arranging them side by side along the longitudinal direction of the electric wire so that the antenna impedance changes depending on when the abnormal portion without the shield member is scanned, And detecting the abnormality of the shield member based on the radio wave received by the receiving antenna; It consists in the abnormality detecting method of the shield member, characterized in that sequentially performed.

  The invention according to claim 2 includes a conductive core wire, an internal insulator that covers the core wire, a shield member that is wound around an outer periphery of the internal insulator, and an external insulator that covers the shield member. In a shield member abnormality detection device for detecting an abnormality of the shield member in an electric wire, the antenna impedance changes between when a normal part with the shield member is scanned and when an abnormal part without the shield member is scanned. The transmission antenna arranged close to the electric wire and the transmission antenna are provided separately from each other, and the antenna impedance is different when scanning a normal part with the shield member and when scanning an abnormal part without the shield member. In order to transmit radio waves from the receiving antenna and the transmitting antenna that are arranged close to the wire so as to change An oscillation circuit that outputs a traveling wave; and an abnormality detection unit that detects an abnormality of the shield member based on a radio wave received by the reception antenna, wherein the transmission antenna and the reception antenna are arranged in a longitudinal direction of the electric wire. It exists in the abnormality detection apparatus of the shield member characterized by arrange | positioning along.

  As described above, according to the first and second aspects of the invention, the transmission antenna and the reception antenna are provided separately and are arranged side by side along the longitudinal direction of the electric wire. As a result, when the vicinity of the abnormal part is scanned with the transmission antenna and the reception antenna, one of the transmission antenna and the reception antenna scans over the abnormal part of the electric wire, and the other scans over the normal part of the electric wire. The impedance of only the other of the antennas is lowered, and the transmission antenna and the reception antenna cannot be matched, and the reception level at the reception antenna is lowered. On the other hand, when the vicinity of the normal part is scanned with the transmission antenna and the reception antenna, both the transmission antenna and the reception antenna scan on the normal part of the wire, and both the transmission antenna and the reception antenna can be matched. The reception level becomes high. Accordingly, since the amount of change in the level of the radio wave received by the receiving antenna depending on the presence / absence of the shield member in a wide band can be increased, a shield member abnormality detection method and apparatus for detecting a shield member abnormality in a wide band are provided. be able to.

It is a block diagram which shows one Embodiment of the abnormality detection apparatus of the shield member which implemented the abnormality detection method of the shield member of this invention. It is a perspective view which shows the meniscus member to which the transmitting antenna and receiving antenna which are shown in FIG. 1 are attached. It is explanatory drawing for demonstrating operation | movement of the abnormality detection apparatus shown in FIG. It is a graph which shows the frequency versus received electric wave W4 characteristic of the abnormality detection apparatus shown in FIG. It is a block diagram which shows an example of the abnormality detection apparatus of the conventional shield member. It is a graph which shows the frequency versus reflected wave W2 characteristic of the abnormality detection apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a shield member abnormality detection apparatus (hereinafter simply referred to as “abnormality detection apparatus”) in which the shield member abnormality detection method of the present invention is implemented. The abnormality detection device 20 detects an abnormality of the copper tape 13 of the CV cable 10 as an electric wire, for example. Here, the abnormality of the copper tape 13 means that the copper tape 13 is displaced and a part of the core wire 11 that is not covered with the copper tape 13 is generated.

  As described in the background art, the CV cable 10 includes a core wire 11, an insulator 12 as an internal insulator, a copper tape 13 as a shield member, and a sheath 14 as an external insulator. . The core wire 11 is made of a conductive conductor. The insulator 12 is made of crosslinked polyethylene or the like and covers the core wire 11. The copper tape 13 is provided in a tape shape and is wound around the outer periphery of the insulator 12. The sheath 14 is made of polyethylene or the like and covers the copper tape 13.

  The abnormality detection apparatus 20 outputs a traveling wave W1 to the transmission antenna AT11, the transmission antenna AT11 that transmits the transmission radio wave W3 toward the CV cable 10, the reception antenna AT12 that receives the transmission radio wave W3 from the transmission antenna AT11, and the transmission antenna AT11. An oscillation circuit 21 that performs reception, a reception circuit 23 that receives a reception radio wave W4 received by the reception antenna AT12, and an abnormality in which the deviation (detection) of the copper tape 13 is determined based on the level of the reception radio wave W4 received by the reception circuit 23 A discriminating circuit 24 as detection means and an alarm circuit 25 for generating an alarm to that effect when the discriminating circuit 24 discriminates that the copper tape 13 is displaced are provided.

  The transmission antenna AT11 and the reception antenna AT12 are provided separately and are composed of the same antenna. The transmission antenna AT11 and the reception antenna AT12 are attached to the meniscus member 30 shown in FIG. 2 so as to be able to scan along the longitudinal direction Y1 of the CV cable 10.

  The half-moon member 30 is formed in a box shape, and a groove 30a having a half-moon-shaped cross section extending linearly from one end to the other end is provided on the bottom surface thereof. The CV cable 10 is fitted into the groove 30a so that the outer diameter of the CV cable 10 matches the inner diameter of the groove 30a. Further, the transmitting antenna AT11 and the receiving antenna AT12 are attached to the upper surface of the meniscus member 30 so as to be arranged at intervals from each other along the longitudinal direction Y1 of the CV cable 10.

  Then, as shown in FIG. 2, when the meniscus member 30 is moved along the longitudinal direction Y1 of the CV cable 10 with the CV cable 10 fitted in the groove 30a of the meniscus member 30, the transmission antenna AT11 and the reception antenna The transmission antenna AT11 and the reception antenna AT12 are arranged in a state where the distance between the AT 12 and the CV cable 10 is kept constant, and the transmission antenna AT11 and the reception antenna AT12 are arranged at intervals from each other along the longitudinal direction Y1. Scanning can be performed along the longitudinal direction Y1 of the CV cable 10. The distances between the transmission antenna AT11 and the reception antenna AT12 and the CV cable 10 are set such that the impedances of the transmission antenna AT11 and the reception antenna AT12 change depending on the presence or absence of the copper tape 13.

  Next, an abnormality detection procedure using the abnormality detection apparatus 20 having the above-described configuration will be described. First, the CV cable 10 is fitted into the groove 30 a of the meniscal member 30. As a result, the antenna impedance of the transmitting antenna AT11 and the receiving antenna AT12 provided separately from each other is changed between when the normal part with the copper tape 13 is scanned and when the abnormal part without the copper tape 13 is scanned. In addition, the CV cable 10 can be arranged close to the CV cable 10 and can be arranged side by side along the longitudinal direction Y <b> 1 of the CV cable 10. Next, the oscillation circuit 21 is operated to oscillate the oscillation circuit 21 at the resonance frequency of the transmission antenna AT11 and the reception antenna AT12 to output a traveling wave W1.

  Thereby, as shown in FIG. 1, most of the traveling wave W1 reaching the transmission antenna AT11 is radiated from the transmission antenna AT11 as a transmission radio wave W3. Further, part of the traveling wave W1 reaching the transmission antenna AT11 is reflected by the transmission antenna AT11 and travels toward the oscillation circuit 21 as an antenna reflected wave W22.

  The radiated transmission radio wave W3 is reflected by the core wire 11 or the copper tape 13 of the CV cable 10 and propagated to the receiving antenna AT12. Or, it is directly transmitted from the transmission antenna AT11 to the reception antenna AT12. The transmission radio wave W3 propagated to the reception antenna AT12 is received by the reception antenna AT12 as the reception radio wave W4. Then, the determination circuit 24 determines the displacement of the copper tape 13 based on the reception level of the received radio wave W4, and when it is determined that the displacement has occurred, the alarm circuit 25 is controlled to generate an alarm to that effect. .

  According to the abnormality detection device 20 described above, the transmission antenna AT11 and the reception antenna AT12 are provided separately, and are arranged side by side along the longitudinal direction Y1 of the CV cable 10 at intervals. As a result, when the vicinity of the abnormal part is scanned by the transmission antenna AT11 and the reception antenna AT12, the reception antenna AT12 scans the abnormal part of the CV cable 10 as shown in FIG. 3A, and the transmission antenna AT11 is scanned by the CV cable 10. The normal part is scanned. As a result, the impedance of only the transmission antenna AT11 is reduced, and the impedance of the reception antenna AT12 is not reduced. Therefore, the transmission antenna AT11 and the reception antenna AT12 cannot be matched, and the reception antenna AT12 cannot receive the transmission radio wave W3 efficiently. The reception level of the reception radio wave W4 decreases.

  On the other hand, when the vicinity of the normal part is scanned with the transmission antenna AT11 and the reception antenna AT12, both the transmission antenna AT11 and the reception antenna AT12 scan over the normal part of the CV cable 10 as shown in FIG. . Thereby, since the transmission antenna AT11 and the reception antenna AT12 can be matched, the reception antenna AT12 efficiently receives the transmission radio wave W3 and the level of the reception radio wave W4 increases. As a result, the amount of change in the level of the received radio wave W4 received by the receiving antenna AT12 depending on the presence / absence of the copper tape 13 in a wide band can be increased. Thus, an abnormality detection device 20 for detecting an abnormality in the copper tape 13 in a wide band is provided. be able to.

  Next, the inventor measured the level of the received radio wave W4 when the oscillation frequency of the oscillation circuit 21 was changed in the abnormality detection device 20 shown in FIG. 1, and confirmed the effect. The results are shown in FIG. Note that, as the transmission antenna AT11 and the reception antenna AT12, the same antenna as the transmission / reception antenna AT2 used when the characteristic shown in FIG. 6 is simulated using the conventional abnormality detection device 20 of FIG. 5 is used. As a result, even if the same transmission antenna AT11 and reception antenna AT12 as the conventional transmission / reception antenna AT2 are used, the amount of change in the received radio wave W4 depending on the presence or absence of the copper tape 13 can be increased in a wide range of 5.6 GHz to 6.0 GHz. It was found that the abnormality of the copper tape 13 can be detected in a wide band.

  In the above-described embodiment, the transmitting antenna AT11 and the receiving antenna AT12 are mounted on the half moon member 30, but the present invention is not limited to this. The transmitting antenna AT11 and the receiving antenna AT12 may be arranged at intervals from each other along the longitudinal direction Y1 of the CV cable 10, and other mounting members may be used.

  In the above-described embodiment, the transmission / reception antenna AT11 and the reception antenna AT12 are arranged at intervals from each other along the longitudinal direction Y1 of the CV cable 10. However, the present invention is not limited to this. The transmission / reception antenna AT11 and the reception antenna AT12 may be arranged along the longitudinal direction Y1, and need not be spaced.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

10 CV cable (electric wire)
11 Core wire 12 Insulator (Internal insulator)
13 Copper tape (shield member)
14 Sheath (external insulator)
20 Abnormality detection device 21 Oscillation circuit 24 Discrimination circuit (abnormality detection means)
AT11 transmitting antenna AT12 receiving antenna

Claims (2)

An abnormality of the shield member in an electric wire having a conductive core wire, an internal insulator covering the core wire, a shield member wound around an outer periphery of the internal insulator, and an external insulator covering the shield member In the method of detecting an abnormality of the shield member to be detected,
The transmission antenna and the reception antenna provided separately from each other are connected to the electric wire so that the antenna impedance changes between when the normal part with the shield member is scanned and when the abnormal part without the shield member is scanned. A step of arranging and arranging along the longitudinal direction of the electric wire,
Transmitting radio waves from the transmitting antenna;
Detecting an abnormality of the shield member based on radio waves received by the receiving antenna;
A method for detecting an abnormality of a shield member, characterized in that the steps are sequentially performed. An abnormality of the shield member in an electric wire having a conductive core wire, an internal insulator covering the core wire, a shield member wound around an outer periphery of the internal insulator, and an external insulator covering the shield member In the abnormality detection device for the shield member to be detected,
A transmitting antenna that is arranged close to the wire so that the antenna impedance changes between when the normal part with the shield member is scanned and when the abnormal part without the shield member is scanned;
It is provided separately from the transmitting antenna, and is arranged close to the wire so that the antenna impedance changes between when the normal part with the shield member is scanned and when the abnormal part without the shield member is scanned. A receiving antenna;
An oscillation circuit that outputs a traveling wave for transmitting radio waves from the transmission antenna;
An abnormality detecting means for detecting an abnormality of the shield member based on the radio wave received by the receiving antenna;
The abnormality detection device for a shield member, wherein the transmission antenna and the reception antenna are arranged side by side along a longitudinal direction of the electric wire.

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