JP5310692B2 - Electric wire deterioration diagnosis device - Google Patents

Description

  The present invention relates to an electric wire deterioration diagnosis apparatus, and more particularly, to an electric wire deterioration diagnosis apparatus that nondestructively diagnoses deterioration of electric wires, cables, and the like using surface hardness as an index.

  Conventionally, as a method for nondestructively diagnosing deterioration of a cable such as an electric wire, a method using the surface hardness of an insulator or sheath on the surface of the cable is known. In this method, the surface hardness of the cable surface is measured using ultrasonic waves and repulsive force, and the degree of deterioration is diagnosed by comparing it with that of a new cable of the same specification.

  For example, Patent Document 1 discloses an apparatus that causes an impactor to collide against the surface of an electric wire / cable and measures the surface hardness of the sheath from the relationship between the speed immediately before the impactor and the speed immediately after rebound. ing. In this type of hardness tester that uses the repulsive force of the cable, the measurement results will vary unless the contact conditions (position, angle, pressing force, etc.) between the measurement part of the hardness tester and the cable are the same. End up. Therefore, in this apparatus, a hardness measuring jig is used to fix the cable at a desired position. Specifically, the hardness measurement jig includes a gripping portion having opposing gripping grooves and a biasing member that constantly biases the wire / cable in the gripping direction when the wire / cable is disposed between the gripping grooves. The gripping portion is provided with a fixing portion for fixing the end of the impactor housing member of the hardness meter and a passage hole through which the impactor can pass. According to such a jig configuration, variation in the contact condition between the impact body and the cable is suppressed.

  Patent Document 2 discloses a probe fixture used in a cable covering material deterioration diagnosis device. In this probe fixture, a cable support made of two rollers parallel to the longitudinal direction of the cable is installed in order to place a round cable. According to this fixture, when the cable is disposed on the cable support, the probe can be fixed to the outer periphery of the cable at an angle toward the center of the cable.

Japanese Patent No. 3014947 JP-A-10-54827

  However, in the hardness measuring jig in the above-described conventional apparatus, the variation in the contact condition between the measurement unit and the cable increases depending on the shape of the cable. That is, in the above conventional hardness measurement jig, in the round shape cable, the vicinity of the center of the cable is always in contact with the measurement part, but in the flat shape cable, the contact condition varies due to a slight inclination of the cable contact surface. Will occur. For this reason, when a flat cable or the like deformed asymmetrically due to deterioration or the like is fixed by the conventional method for fixing a hardness measuring jig, the surface hardness of the cable may not be measured with high accuracy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electric wire deterioration diagnosis apparatus that can accurately measure the hardness of a cable surface such as an electric wire with a simple configuration. .

The electric wire deterioration diagnosis apparatus according to the present invention has a flat pressure surface and a push needle provided so as to protrude from the pressure surface, and measures the hardness by pressing the push needle against the measurement region of the measurement target electric wire. A hardness meter, a clamping part that clamps the measurement target electric wire between the pressing surface, a biasing mechanism that biases the pressing surface and the clamping part in the direction of clamping the measurement target electric wire, and a measurement target in the clamping unit and a protrusion provided on the surface on the side for holding the wire, protrusions, so that the most protruding portion of the protruding portion is positioned on the central axis of the indentor in while holding the measurement target wire and it is characterized in that it is disposed.

  According to the electric wire deterioration diagnosis apparatus of the present invention, the hardness of the surface of a cable such as an electric wire can be accurately measured with a simple configuration, so that the reliability of the electric wire deterioration diagnosis is improved and widely used. I can expect that.

It is a figure which shows the outline of the rubber hardness meter used in Embodiment 1 of this invention. It is the schematic which shows the electric wire deterioration diagnostic apparatus used in Embodiment 1 of this invention. It is a figure which shows an example of the electric wire as a measurement sample, Comprising: In the figure, (A) has shown the side view of the electric wire, and (B) has shown sectional drawing, respectively. It is a figure for demonstrating the method of measuring the hardness of an electric wire sample using a rubber hardness meter, Comprising: (A) in a figure shows the state before hardness measurement, (B) shows the state under hardness measurement, respectively. ing. It is a figure which shows the state before measuring the hardness of an electric wire sample using an electric wire degradation diagnostic apparatus. It is a figure which shows the state which has arrange | positioned the electric wire sample to the electric wire deterioration diagnostic apparatus. It is a figure which shows the state which is measuring the hardness of an electric wire sample using an electric wire degradation diagnostic apparatus. It is a figure for demonstrating the modification of the electric wire deterioration diagnostic apparatus used in Embodiment 1 of this invention. It is a figure for demonstrating the measuring method of the insulation resistance value implemented by this evaluation test.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1 FIG.
[Configuration of this embodiment]
First, the configuration of the rubber hardness meter used in the present embodiment will be described with reference to FIG. FIG. 1 is a diagram schematically showing a rubber hardness meter 1 used in Embodiment 1 of the present invention. As shown in this figure, the rubber hardness meter 1 includes a dial 2 indicating hardness, an attachment portion 3, a contact plate 4, and a push needle 5 as a measurement tool. The contact plate 4 has a flat pressure surface 6 applied to a sample to be measured, and is provided so that the push needle 5 protrudes from the vicinity of the center of the pressure surface 6. As such a rubber hardness meter 1, for example, an AL type rubber hardness meter manufactured by Kobunshi Keiki Co., Ltd. can be used.

  Next, with reference to FIG. 2, the structure of the electric wire deterioration diagnostic apparatus of this Embodiment is demonstrated. FIG. 2 is a schematic diagram showing the electric wire deterioration diagnosis device 10 used in the first embodiment of the present invention. As shown in this figure, the electric wire deterioration diagnosis device 10 includes a first member 11 and a second member 12 as plate members formed in a crank shape. The first member 11 and the second member 12 are arranged so as to intersect with each other, and the intersecting portion is rotatably joined by a pin 13. According to such a configuration, the other end can be operated by inputting an external force to one end of the first member 11 and the second member 12. In the following description, the external force input side of the first member 11 and the second member 12 will be referred to as the input portions 111 and 121, and the other end side will be referred to as the clamping portions 112 and 122.

  The electric wire deterioration diagnosis device 10 according to the present embodiment includes a rubber hardness meter 1. The rubber hardness scale 1 is disposed so that the pressing surface 6 faces the sandwiching portion 122 of the second member 12 by fixing the attachment portion 3 to the sandwiching portion 112 of the first member 11. Moreover, the guide part 14 for arrange | positioning a measuring object electric wire in a predetermined | prescribed measurement position is installed in the clamping part 122 of the 2nd member 12. FIG. The guide portion 14 is a protrusion for positioning the measurement target electric wire in the width direction, and is provided so that a wire width groove is formed around the central axis C of the push needle 5.

  A spring 15 is attached between the input part 111 of the first member 11 and the input part 121 of the second member 12. The spring 15 is for constantly urging the pressing surface 6 and the clamping part 122 in the direction in which the measurement target electric wire is clamped. For this reason, as shown in this figure, when the external force is not input to the apparatus, the pressure surface 6 and the upper surface of the guide portion 14 are maintained in contact with each other.

  A projecting portion 16 having a spherical tip shape is provided on the sandwiching portion 122 of the second member 12. The protrusion 16 is installed at a position where the center axis thereof coincides with the center axis C of the push needle 5 in a state where the measurement target electric wire is sandwiched. The height of the protrusion 16 and the height of the guide portion 14 are pressed when the measurement target electric wire is clamped when the measurement surface of the electric wire is slightly higher than the guide portion 14 and the measurement target electric wire is not arranged. The height is set such that the needle 5 and the protrusion 16 do not contact each other.

[Characteristic operation of this embodiment]
Next, with reference to FIG. 3 thru | or FIG. 7, the characteristic operation | movement of the electric wire deterioration diagnostic apparatus 10 of this Embodiment is demonstrated. In the present embodiment, the hardness of the electric wire is measured using the electric wire deterioration diagnosis device 10. FIG. 3 is a diagram illustrating an example of an electric wire as a measurement sample. In addition, (A) in this figure shows a side view of the electric wire as a sample, and (B) shows a cross-sectional view when the electric wire shown in (A) is cut in a direction perpendicular to the extending direction. Yes. As shown in this figure, the electric wire sample 20 is configured by covering a conductive wire in which a copper wire 21 is covered with an insulating layer 22 of each color (white, red, black), and further with an insulating sheath layer 23 such as vinyl chloride. ing. In general, when connecting an electrode terminal or the like to an electric wire, as shown in FIG. 2A, the end insulating layer 22 and the sheath layer 23 are peeled off, and the copper wire 21 and the electrode terminal are connected. Use. Hereinafter, although it demonstrates using the electric wire sample 20 as a measurement object electric wire, the electric wire which can measure hardness with the electric wire deterioration diagnostic apparatus 10 is not restricted to this.

  Next, with reference to FIG. 4, the basic operation of the rubber hardness meter 1 used in the electric wire deterioration diagnosis device 10 of the present embodiment will be described. FIG. 4 is a view for explaining a method of measuring the hardness of the electric wire sample 20 using the rubber hardness meter 1. In this figure, (A) shows the state before the hardness measurement, and (B) shows the state during the hardness measurement. As shown in this figure, when measuring the hardness, the measurement surface (sheath layer 23) of the wire sample 20 is pressed with the tip of the push needle 5 of the rubber hardness meter 1. At this time, the center axis of the push needle 5 is pressed in a direction perpendicular to the measurement surface of the wire sample 20 (that is, in the direction of arrow F in the figure). And the value which the needle | hook of the dial 2 shows when the pressurization surface 6 of the rubber hardness meter 1 contacts the measurement surface of the electric wire sample 20 is acquired as the hardness of the measurement part. In addition, a spring having a spring constant conforming to JIS K6253 is built in the rubber hardness meter 1, and the repulsive force against this spring is defined as hardness. The rubber hardness tester 1 can measure samples with different rubber hardnesses according to JIS K6253, but the A type or AL type is desirable from the viewpoint of the sheath surface hardness. Moreover, the hardness of the sheath layer 23 of the electric wire sample 20 is generally 78 to 84, and becomes 90 or more when the sheath layer 23 is cured by the influence of heat, ultraviolet rays, oxidation, or humidity.

  Next, a method for measuring the surface hardness of the wire sample 20 using the wire deterioration diagnostic device 10 of the present embodiment will be described. FIG. 5 is a diagram illustrating a state before the hardness of the wire sample 20 is measured using the wire deterioration diagnosis device 10. When measuring the hardness of the wire sample 20, first, as shown in this figure, an external force is applied in the T direction in the figure so that the clamping parts 112 and 122 are separated from each other. Thereby, the pressing surface 6 of the rubber hardness meter 1 that has been in contact with the guide portion 14 of the clamping portion 122 moves upward.

  Next, the wire sample 20 is disposed. FIG. 6 is a diagram illustrating a state in which the wire sample 20 is arranged in the wire deterioration diagnosis apparatus 10. As shown in this figure, the wire sample 20 is disposed between the guide portions 14 in the sandwiching portion 122. Thereby, the lower surface of the wire sample 20 is supported by the protrusions 16, and the side surfaces of the wires are supported by the guide portions 14. As described above, the upper surface (measurement surface) of the wire sample 20 is slightly higher than the guide portion 14. Thereby, it is possible to effectively bring the pressing surface 6 into contact with the upper surface of the wire sample 20 during measurement while positioning the wire sample 20 in the width direction.

  Next, the hardness of the wire sample 20 is measured. FIG. 7 is a diagram showing a state in which the hardness of the wire sample 20 is measured using the wire deterioration diagnosis device 10. As shown in this figure, when the external force applied to the input units 111 and 112 is removed, the rubber hardness meter 1 descends toward the wire sample 20 and the push needle 5 presses the upper surface (measurement surface) of the wire sample 20. At the same time, the pressing surface 6 contacts the upper surface (measurement surface) of the wire sample 20. The lower surface of the wire sample 20 is supported at one point by the protrusion 16. For this reason, the direction of the measurement surface of the electric wire sample 20 is corrected in a direction in close contact with the pressure surface 6 (that is, a direction parallel to the pressure surface 6). Thereby, since the push needle 5 can be always pressed on the measurement surface of the electric wire sample 20 on the same conditions, measurement variation is suppressed effectively. Thus, according to the electric wire deterioration diagnosis apparatus 10 of the present embodiment, the hardness can be measured with high accuracy even for a flat electric wire or an electric wire deformed due to deterioration or the like.

  By the way, in Embodiment 1 mentioned above, although it is supposed that a board | plate material will be used as the 1st member 11 and the 2nd member 12, these members do not need to be a board and have the intensity | strength which does not have a problem in a measurement. The same function may be given by bending or welding. As a result, it is possible to reduce the weight and size, and thus it is possible to provide a more convenient wire deterioration diagnosis device.

  Moreover, in Embodiment 1 mentioned above, although it is supposed that the 1st member 11 and the 2nd member 12 cross | intersect and couple | bond with the pin 13, the structure as the electric wire deterioration diagnostic apparatus 10 is not restricted to this. . FIG. 8 is a diagram for explaining a modification of the electric wire deterioration diagnosis apparatus used in Embodiment 1 of the present invention. In the apparatus shown in this figure, the first member 11 and the second member 12 are coupled by a pin 13 without intersecting. The spring 15 is used to constantly urge the pressing surface 6 and the clamping part 122 in the direction in which the measurement target electric wire is clamped, that is, the direction in which the input parts 121 and 122 are separated from each other. According to the electric wire deterioration diagnosis device configured as described above, the holding portions 112 and 122 of the device can be separated by an operation of grasping the input unit 121 and the input unit 122 with a hand, so that the usability is improved.

[Evaluation experiment]
Next, an evaluation experiment using the electric wire deterioration diagnosis apparatus 10 according to the first embodiment will be described. In this evaluation test, an AL type rubber hardness meter manufactured by Kobunshi Keiki Co., Ltd. was used as the rubber hardness meter 1. Moreover, as the electric wire sample 20, as for the color of the vinyl chloride coating | cover, a vinyl chloride sheath electric wire, copper wire 7 diameter φ1.6mm, and the insulating layer 8 by Yazaki Electric Wire Industry Co., Ltd., red (R), white (W ) And black (B), and the sheath 9 is gray, the length of the sheath 9 is 20 cm, the length of the insulating layer 8 at both ends is 3 cm, and the length of the copper wire 7 is 1 cm. 18 pieces were cut so as to be. Table 1 shows the results of measuring the hardness of the wire sample 20 using the wire deterioration diagnosis device 10 of the first embodiment.

  From the results shown in Table 1, the surface hardness of the sheath 9 was measured as 79 to 81. On the other hand, as a comparative example, the same measurement was performed by directly holding the rubber hardness meter 1 by hand without using the wire deterioration diagnosis device 10 of the present invention. Here, specifically, an electric wire sample was placed on a table, and the push needle 5 of the rubber hardness meter 1 was manually pressed against the sheath surface of the sample, and measurement was performed. The measurement results of the comparative example are shown in Table 2.

  From the results shown in Table 2, the surface hardness of the sheath 9 varied widely from 72 to 81, and many lower hardnesses were measured. This is presumed to be because the wire sample is relatively soft and does not have a uniformly flat shape, so that the push needle 5 cannot always be brought into contact with the sheath surface under the same conditions. From the above, it was shown that the electric wire deterioration diagnosis device 10 of the present invention can measure the surface hardness of the electric wire sample with high accuracy with little measurement variation.

  Next, eight electric wire samples 20 were prepared, and the surface hardness and insulation resistance value after being held in a high-temperature tank set at 100 ° C. for 0, 100, 250, and 1000 hours were measured. The insulation resistance value can be used as an index indicating the degree of deterioration of the electric wire. This is because when the insulating layer or the sheath is cured by heat, ultraviolet rays, humidity, oxidation, etc., the insulation performance is also lowered and the insulation resistance value is lowered. In this evaluation test, the insulation resistance value of the wire sample 20 was measured by the following method. FIG. 9 is a diagram for explaining a method of measuring an insulation resistance value performed in this evaluation test. As shown in this figure, in this measurement, the red wire (R) on one end side of the electric wire sample 20 and the white wire (W) on the other end side are connected, and an insulation resistance meter (for example, 4339A manufactured by Hewlett-Packard Co., Ltd.) is connected. ) And applying a voltage across the copper wire portion with a predetermined probe. The voltage was 500 V, the measurement time was set to the long mode, and the insulation resistance value R1 30 seconds after the start of measurement was measured. The measurement results are shown in Table 3, Table 4, Table 5, and Table 6, respectively.

  From the results shown in Tables 3 to 6, it can be seen that the hardness of the electric wire increases with an increase in the heat treatment time, but when the hardness is 94 or more, the insulation resistance is significantly reduced. From the above, it has been shown that according to the present invention, the measurement accuracy of the sheath surface hardness of the wire sample is improved, and thereby the deterioration degree of the wire can be estimated with high accuracy.

Embodiment 2. FIG.
In the second embodiment, the electric wire deterioration diagnosis device 10 shown in the first embodiment described above was produced by bending or welding a wire instead of a plate material, and the same evaluation test was performed. As a result, the hardness measurement result of the wire sample 20 was exactly the same as that obtained in the first embodiment. In the electric wire deterioration diagnosis device 10 according to the second embodiment, since the weight of the device is reduced, the time for setting the electric wire sample 20 can be shortened, and the effect is that 20 electric wire samples are measured. The time required for the process can be reduced to about ½. From the above, it has been shown that by reducing the weight of the apparatus, it is possible to effectively increase the working efficiency while improving the measurement accuracy.

Embodiment 3 FIG.
In this Embodiment 3, the evaluation test performed in the said Embodiment 2 was implemented by increasing the kind of electric wire sample. For example, the same Yazaki Electric Co., Ltd., 3-core wire with a diameter of φ2.0 mm, Furukawa Electric, and Sumiden-Hitachi's similar 3-core wires and 4-core wires with φ2.0 mm, as well as the sheath material not only vinyl chloride, It was carried out by changing eco-electric wires (details of materials etc. are unknown for each company), rubber, cross-linked polyester, etc. Furthermore, the same evaluation was performed by changing the processing conditions of the wire sample to 85 ° C. high temperature standing, 85 ° C. and 85% RH high temperature and high humidity processing.

  As a result, it was confirmed that the relationship between the rubber hardness of the sheath material and the insulation resistance value was 10-11 or less when the hardness was 90 or more. From this result, it was shown that it can be determined that the electric wire has deteriorated by determining NG when the rubber hardness of the sheath material is 90 or more. Moreover, as a result of actually investigating the relationship between the surface hardness of the sheath material and the insulation resistance at the construction site, similar results were obtained. Thus, the hardness of the electric wire is closely related to the degree of deterioration. Therefore, the presence / absence of the deterioration of the electric wire can be determined by providing the deterioration diagnosis means for determining whether the NG should be determined for each electric wire in advance and determining whether the measured hardness is higher than the specified predetermined value. It can be determined with high accuracy.

  Based on the present invention, for example, the shape of the push needle 5 of the rubber hardness tester 1 can be made more reliable by flattening the surface to a diameter equal to or smaller than the diameter of the electric wire. In other words, the rubber hardness tester 1 is JIS at this stage, and the shape of the push needle 5 and the strength of the built-in spring (spring constant) are specified, which is not appropriate depending on the degree of cure of the sheath of the electric wire or the insulating layer. However, high reliability can be achieved by changing the shape of the push needle 5 and the built-in spring constant according to the electric wire used. However, since it deviates from the JIS standard at this stage, the A type or the AL type is most desirable in view of the versatility of data.

DESCRIPTION OF SYMBOLS 1 Rubber hardness meter 5 Push needle 6 Pressurization surface 11 1st member (biasing mechanism)
12 Second member (biasing mechanism)
122 clamping part 13 pin (biasing mechanism)
14 Guide 15 Spring (elastic member, biasing mechanism)
16 Protrusion 20 Wire sample (Measurement target wire)

Claims (6)

A rubber hardness meter that has a flat pressure surface and a push needle provided so as to protrude from the pressure surface, and measures hardness by pressing the push needle against a measurement region of a measurement target wire;
A clamping part for clamping the measurement target electric wire between the pressing surface;
An urging mechanism that urges the pressing surface and the clamping portion in a direction of clamping the measurement target electric wire;
A projection provided on a surface of the clamping unit on the side of clamping the measurement target electric wire,
The protrusion of the previous SL wire degradation diagnostic apparatus characterized by outermost projections are arranged such that the position of the projections on the center axis of said indentor of the measured electric wire in a state of sandwiching.   The wire deterioration diagnosis apparatus according to claim 1, wherein a tip shape of the protrusion is spherical. The biasing mechanism is
The rubber hardness meter is disposed on one end side, and a first member having an input portion for inputting external force on the other end side;
A second member provided with an input part for inputting an external force on the other end side, wherein the clamping part is disposed on one end side;
A pin for rotatably connecting the first member and the second member;
An elastic member that urges the first member and the second member in a direction to sandwich the measurement target electric wire;
The wire deterioration diagnosis apparatus according to claim 1 or 2 , characterized in that The guide unit further includes a guide unit that is positioned in the clamping unit and performs positioning in the width direction of the measurement target electric wire, and the height of the guide unit is a height that does not contact the pressing surface when the measurement target electric wire is clamped. The electric wire deterioration diagnosis device according to any one of claims 1 to 3, wherein the electric wire deterioration diagnosis device is set. The electric wire deterioration diagnosis apparatus according to any one of claims 1 to 4 , wherein the electric wire deterioration diagnosis apparatus is adjusted in size, weight, and strength to a range that can be operated with one hand. When the hardness measured at a rubber hardness meter is higher than a predetermined value, any one of claims 1 to 5 wherein the measurement target wire is characterized, further comprising a deterioration diagnosis means determines that the deteriorated The electric wire deterioration diagnosis device according to item 1.

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