JP3725747B2 - Ultrasonic degradation diagnostic equipment for low-voltage cable for railway equipment - Google Patents

Description

【００５７】
実施例および比較例として製作したケーブル保持具の評価を表２に示す。
表２では、温度測定の応答性については、応答に要する秒数を４段階に分け、１０秒以内の応答を「◎」、１５秒以内を「○」、３０秒以内を「△」、３１秒以上を「×」で示している。
また、温度測定値の安定性については、温度変動幅を４段階に分け、１℃以内の変動を「◎」、２℃以内を「○」、４℃以内を「△」、５℃以上を「×」で示している。
また、ケーブルの把持安定性については、観察の結果を４段階に分け、ずれ無しを「◎」、僅かなずれを「○」、大きなずれを「△」、落下を「×」で示している。
【００５８】
【表２】

【００５９】
表２に示すとおり、良熱伝導性部材を設けた本発明の装置の方が、設けない比較例よりも、ケーブルの表面温度に迅速に応答しかつ安定していることが明らかとなった。また、ケーブル保持具の操作性の点では、溝面に滑り止めを施した本実施例のものは、バネの力でケーブルを挟むだけで、手を離しても温度センサが被覆層の表面からずれることがなかった。このことから、高所や狭隘な部分など、診断装置をケーブルに対して手で保持しにくい場所でも、正確な劣化診断が可能であることがわかった。
【００６０】
【発明の効果】
以上説明したとおり、本発明の超音波劣化診断装置は、簡単な構成でありながら、鉄道用低圧ケーブルの敷設現場において被覆層の表面温度を正確にかつ迅速に測定できる。従って、測定される超音波伝搬特性に対してその場で正確な温度補正が可能であり、ひいては正確でかつ迅速な劣化診断が可能である。
また、本発明の超音波劣化診断装置は、鉄道設備の保守現場での使用に適したケーブル保持具を備えているから、検査員の作業性を改善し、正確でかつ迅速な劣化診断が可能となっている。
【図面の簡単な説明】
【図１】本発明による超音波劣化診断装置の一構成例を示す模式図である。
【図２】本発明おいて、超音波劣化診断装置に付与されたケーブル保持具の一構成例を示す模式図である。図２（ａ）は、ケーブルＣを挟んだ状態を示している。ケーブルＣは紙面と垂直に交わっている。図２（ｂ）は、図２（ａ）に示すケーブル保持具のプローブ部４の、ケーブルに対する接触面を見せた斜視図である。
【符号の説明】
１ 超音波送信手段
２ 超音波受信手段
３ 温度測定手段
３１ 良熱伝導性部材
３２ 温度センサ
４ プローブ部
５ 制御部
Ｃ 鉄道用低圧ケーブル
Ｃ１ 被覆層
Ｗ 超音波[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of diagnosing deterioration of electric cables using ultrasonic waves, and in particular, low voltage electric cables for railway facilities (hereinafter also referred to as “low voltage cables for railway” or simply “cables”). The present invention relates to a diagnostic apparatus for diagnosing the above.
[0002]
[Prior art]
Low-voltage cables for railways are laid for power supply to a large number of facilities and equipment provided along the track and supply of signal current for controlling them, and play an important role for all facilities along the railway Is fulfilling. Examples of facilities along the railway line include signal devices / breakers such as railroad crossings, devices related to points, various monitoring devices and control devices.
[0003]
If defects such as insulation failure due to deterioration occur in the coating layer of the low-voltage cable for railways (insulator layer made of organic polymer material that coats the outer periphery of the conductor), safe and stable vehicle operation and There is a risk of hindering operations. For this reason, the insulation performance test is regularly implemented with respect to the low voltage cable for railways more frequently than the general low voltage cable.
[0004]
Conventionally, in insulation performance tests for low-voltage cables for railways, the insulation resistance between the cable phases (for example, between the cables corresponding to each phase of three-phase AC) or the ground is electrically measured, or the ultra-low frequency current is measured. The insulation performance was directly measured by extracting the leakage component by applying the superimposed current.
[0005]
[Problems to be solved by the invention]
However, in the conventional diagnostic method as described above, it is necessary to make a power failure during measurement. Since the railway facilities are in operation for 24 hours throughout the year, there are many safety problems for inspectors and time constraints on deterioration diagnosis. Inspectors are forced to carry out strict inspection work in order to accurately diagnose cable deterioration within such a limited time. In addition, there is a problem that large-scale equipment such as power supply equipment is necessary for measurement.
[0006]
In order to solve the above problems, the present inventors first tried to diagnose a cable in a live line state by applying a deterioration diagnosis method using ultrasonic waves to a low-voltage cable for railways. However, further examination of the embodiment of the ultrasonic deterioration diagnosis at the maintenance site of the railway equipment revealed that the ultrasonic deterioration diagnosis has the following problems because it is used for railways. It was.
[0007]
(1) Since the work is performed in the immediate vicinity or inside the train tracks and facilities, it is dangerous, and it is difficult to ensure the safety of workers in long-time work.
(2) Since the diagnosis work is performed with security personnel for the reason of (1) above, the labor cost increases as the time increases.
(3) The railway track is long, and there are many diagnostic points even in a specific section, and it is not preferable to perform a low-efficiency work that takes time to diagnose one point.
(4) In order to perform ultrasonic diagnosis under various environments along the railway, it is necessary to correct to a specific temperature, and therefore, the surface temperature of the cable to be diagnosed must be measured. However, when diagnosing inside a control box such as a power supply / electric box or a trough (a concrete groove along the track where the wire is housed), the control box or trough lid is used for diagnosis. The cable temperature changes rapidly due to direct sunlight or outside air. Therefore, if the ultrasonic propagation characteristics are not performed quickly, propagation measurement cannot be performed under actual temperature, and if the cable surface temperature is not measured quickly, the actual temperature cannot be obtained and accurate temperature correction cannot be performed. .
[0008]
As described above, rapid measurement work is required at the maintenance site of railway facilities. In particular, in order to cope with the problem (4), the surface temperature of the coating layer must be measured quickly and accurately. I understand.
[0009]
An object of the present invention is to provide an ultrasonic degradation diagnosis apparatus suitable for use in a maintenance site of railway facilities, which can accurately and quickly diagnose degradation of low-voltage cables for railways with simple equipment, solving the above problems. It is to be.
[0010]
[Means for Solving the Problems]
  The ultrasonic degradation diagnostic apparatus of the present invention has the following characteristics.
(1) Diagnosis of low-voltage cable for railway facilities having a coating layer made of organic polymer materialAn ultrasonic degradation diagnostic device,
  The device isUltrasonic transmitting means, ultrasonic receiving means, propagation time measuring means for measuring propagation time when ultrasonic waves propagate through the coating layer from the transmitting means to the receiving means, and measuring the surface temperature of the coating layer Temperature measuring means to
The ultrasonic transmission means, the ultrasonic reception means and the temperature measurement means are each separated into a probe part and a control part,
  The temperature measuring meansAs a probe partA heat conductive member for contacting the surface of the coating layer, and a temperature sensor attached to the member.Have
The probe parts of the ultrasonic transmission means, the ultrasonic reception means, and the temperature measurement means are combined into one probe part,
Furthermore, the device has a cable holder,
The cable holder has a structure in which two levers are linked in a link at the fulcrum, and the low-voltage cable is sandwiched by the restoring force of an elastic body,
A probe portion combined with the one and a receiving member for receiving the cable are provided in a portion sandwiching the cable, and a groove is provided in the receiving member, and the groove and the one are combined. The cable is sandwiched between and held by the probe part, and the probe part of the ultrasonic transmission means, the ultrasonic reception means, and the temperature measurement means is fixed on the surface of the coating layer in a state where the probe parts are combined into one. It is configured to contact with loadAn ultrasonic deterioration diagnostic apparatus for low-voltage cable for railway equipment.
(2) The ultrasonic transmission means is configured to be able to install an ultrasonic oscillator on the surface of the coating layer via a delay chip,
The ultrasonic receiving means is configured to be able to install the ultrasonic detection element via a delay chip at a position away from the ultrasonic transmission means by a predetermined distance on the surface of the coating layer.
Of the probe unit combined into one, the surface contacting the coating layer is exposed to the delay chip of the ultrasonic transmission means, the delay chip of the ultrasonic reception means, and the good heat conductive member of the temperature measurement means. The ultrasonic degradation diagnostic apparatus according to (1) above.
(3) The ultrasonic deterioration diagnosis apparatus according to (1), wherein the good heat conductive member is made of copper, copper alloy, aluminum, or aluminum alloy.
(4) Furthermore, it has a calculating part,
The calculation unit has a deterioration diagnosis data group in which the ultrasonic propagation characteristic and the deterioration diagnosis characteristic correspond to the material of the coating layer, and the ultrasonic propagation characteristic including the propagation time is obtained from the temperature obtained by the temperature measuring unit. The ultrasonic deterioration diagnosis apparatus according to (1), wherein the ultrasonic deterioration diagnosis apparatus is configured to perform temperature correction using the deterioration diagnosis data group and obtain a deterioration diagnosis characteristic of the coating layer.
(5) The ultrasonic deterioration diagnosis apparatus according to (1), wherein the surface of the groove is provided with a slip stopper for the low-voltage electric cable to be held.
(6) The above-mentioned anti-slip is one in which a surface of the groove is roughened, or a layer made of an elastic material is provided on the surface of the groove (5) ) Ultrasonic degradation diagnostic device as described.
[0015]
[Action]
The method for diagnosing cable degradation by ultrasonic waves utilizes the fact that the propagation characteristics of ultrasonic waves (propagation speed, propagation time, etc.) of the layer change according to the degree of degradation of the organic polymer material constituting the coating layer. In this method, the propagation characteristic is measured and the corresponding deterioration diagnosis characteristic is obtained from the measured value.
[0016]
Propagation characteristics (propagation speed, propagation time, etc.) of ultrasonic waves propagating through the coating layer show temperature dependence and are greatly influenced by the temperature of the coating layer. For low-voltage cables for railways that are exposed to the outside air or sunlight, measure the propagation temperature and the surface temperature of the coating layer accurately, and measure the propagation time at the standard temperature. Must be corrected. Moreover, as described in the above “Description of Problems to be Solved by the Invention”, accurate measurement is difficult unless the temperature measurement is rapid.
[0017]
Therefore, in this invention, while setting it as the structure which can measure the surface temperature of the coating layer of a cable, it was set as the structure which provided a heat conductive member at the front-end | tip of a temperature sensor, and measured temperature through this member. Since this good heat conductive member quickly reaches the surface temperature of the coating layer, the temperature detection part of the temperature sensor can quickly and accurately detect the temperature of the coating layer surface via the good heat conductive member. In addition, since the heat-conductive member has an appropriate heat capacity, temperature disturbance from the outside such as solar radiation and wind is suppressed. That is, it is possible to perform temperature measurement that achieves both high temperature responsiveness to the measurement object and stability of measurement against temperature disturbance from the outside.
[0018]
Furthermore, when the inspector's measurement work operation at the maintenance site was observed, the contact tends to become unstable when the diagnostic device is brought into contact with the cable coating layer, resulting in large variations in the measured values and the diagnosis result. It was found that the accuracy of was low. In the present invention, as a more preferable aspect, a holding tool having a groove provided with a non-slip is used, and the cable is securely connected by the ultrasonic transmitting means, the ultrasonic receiving means, the temperature measuring means, and the groove of the holding tool. It was set as the structure hold | gripped. This facilitates measurement work, stabilizes the contact state between the diagnostic device (particularly the temperature measurement means) and the cable covering layer, and reduces the variation in measured values.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, an ultrasonic degradation diagnosis apparatus according to the present invention includes an ultrasonic transmission means (hereinafter referred to as “transmission means”) 1, an ultrasonic reception means (hereinafter referred to as “reception means”) 2, and a propagation time measurement. Means (included in the control unit 5 in FIG. 1) and temperature measuring means 3 at least. The transmission unit 1, the reception unit 2, and the temperature measurement unit 3 are in contact with the surface of the covering layer C1 of the cable C.
[0020]
The transmitting means 1 sends out the ultrasonic wave W toward the receiving means 2 to the coating layer C1, and the receiving means 2 receives it at a position away from the transmitting means 1 by a predetermined distance. The propagation time measuring means measures the time required for the ultrasonic wave W to propagate from the transmitting means to the receiving means (time from transmission to reception). When the propagation time is obtained, it is converted as it is or into another form of propagation characteristics, the temperature is corrected, and the value of the deterioration diagnosis characteristic of the coating layer is obtained from the value. In order to perform this temperature correction, temperature measuring means 3 for measuring the surface temperature of the coating layer is provided. The temperature measuring means 3 includes a good heat conductive member 31 for directly contacting the coating layer, and a temperature sensor 32 attached thereto. As described in the above description of the operation, the diagnosis apparatus configured as described above can accurately correct the temperature of the propagation characteristics, and can correctly diagnose deterioration.
[0021]
The railway low-voltage cable to be diagnosed is an insulated wire for DC 750 V or less and AC 600 V or less, which is defined in the electric equipment technical standards. As shown in FIG. 1, the cable has an insulating layer made of an organic polymer material as a coating layer outside the central conductor C2. As the organic polymer material, thermoplastic resins such as polyethylene and polypropylene, natural and synthetic rubbers, thermoplastic elastomers, and the like are used.
[0022]
The transmission unit and the reception unit are devices that transmit and receive ultrasonic waves using the coating layer as a propagation path. The transmission means and the reception means indicate not only the probe portion at the tip attached to the coating layer but also the entire system for transmitting and receiving ultrasonic waves, respectively, an ultrasonic transducer (transmission) and an ultrasonic detection element ( In addition to a conversion element such as (receiver), a drive circuit system for supplying and amplifying electric energy, a delay chip interposed between the element and the covering layer, and the like are included.
[0023]
In the example of FIG. 1, the entire configuration of the diagnostic apparatus is separated into a probe unit 4 attached to the covering layer and a control unit 5 connected to the probe unit 4 by wire (may be wireless). 1, the receiving means 2 and the temperature measuring means 3 are also separated into a probe part and a control part, respectively. For example, in the transmission unit 1, the delay chip 11 and the conversion element 12 are included in the probe unit 4, and the drive circuit system is included in the control unit 5. However, not only such a separate type but also a mode in which the drive circuit system and the probe unit are integrated, and the integrated type / separated type in each means can be freely selected for each means. Good. In the example of FIG. 1, from the viewpoint of preferable operability, the probe units of the transmission unit 1, the reception unit 2, and the temperature measurement unit 3 are combined into one probe unit 4, but only the temperature measurement unit 3 is used. Integration / separation of each means, such as an aspect of making them independent, may be freely selected.
[0024]
The method of transmitting and receiving ultrasonic waves includes a method of emitting ultrasonic waves in the internal direction perpendicular to the surface of the coating layer and receiving waves reflected by the deep layer at the same position, and an ultrasonic wave obliquely downward from the surface of the coating layer. However, various known methods such as a method of reflecting at a deep layer and receiving at a distant position may be used. Among them, the method of directly propagating ultrasonic waves along the surface of the coating layer to the receiving means using the delay chip is a method that can calculate the propagation velocity only by the amount of [time, linear distance] that can be clearly measured from the outside. It is. In the following, the present invention will be described with respect to a mode in which ultrasonic waves are propagated along the surface of the coating layer using a delay chip for the transmitting means, receiving means, propagation time measuring means, and the like.
[0025]
As shown in FIG. 1, in the transmission unit 1, the ultrasonic oscillator 12 is installed on the surface of the coating layer C <b> 1 via the delay chip 11. In the reception unit 2, the ultrasonic detection element 22 is installed on the surface of the coating layer C <b> 1 via the delay chip 21 at a position away from the transmission unit 1 by a predetermined distance. With this configuration, the ultrasonic wave W transmitted from the transmission unit 1 enters the coating layer via the delay chip 11. The delay chip 11 is made of a material selected in terms of ultrasonic propagation speed with respect to the material of the coating layer, and the inclination angle is selected. The ultrasonic wave changes the propagation direction at the interface between the delay chip and the coating layer, and the coating is performed. It propagates linearly along the surface of the layer (that is, through the surface of the covering layer and near the surface) to the position of the receiving means 2 and is received by the detection element 22 via the delay chip 21. The propagation time at that time is measured by the propagation time measuring means.
[0026]
The delay chip is interposed between the conversion element and the coating layer, refracts the propagation direction of ultrasonic waves, sends it along the surface of the coating layer, and propagates along the surface. It is comprised so that an ultrasonic wave can be received. For the basic structure of the delay chip, reference may be made to the prior art.
[0027]
An area from the surface of the coating layer to a depth of about 3 mm is mainly on the surface of the coating layer where the ultrasonic wave propagates and in the vicinity of the surface. Therefore, there is no problem when the covering layer is sufficiently thick, but for example, when the thickness is only 1.5 mm, a part of the ultrasonic wave is a layer below the covering layer (a conductor in a cable, the next layer adjacent to the bottom of the covering layer). ) Or the reflection between the interface and the surface of the coating layer to propagate, and there are cases where accurate propagation characteristics cannot be measured. Therefore, in order to measure more accurately, for example, the ultrasonic wave is propagated at a depth of about 1 mm from the surface of the coating layer and the surface is linearly transmitted from the transmitting means to the receiving means at a depth that does not reach the lower layer. It is preferable to propagate it.
[0028]
There is no restriction | limiting in the frequency of the ultrasonic wave used by this invention. Organic polymer materials such as polyethylene, polyvinyl chloride, and ethylene / propylene copolymer rubber (EPM) that are frequently used for cable coating layers generally have a large attenuation of ultrasonic waves, so that the attenuation is relatively small. A frequency of about ˜5 MHz, particularly about 0.5 to 2 MHz is preferred.
[0029]
The propagation characteristic may be an amount indicating a propagation state when ultrasonic waves are propagated in the material of the coating layer and has a correlation with deterioration of the material. For example, in addition to the particularly useful propagation time and propagation speed, there are ultrasonic reception sensitivity, frequency change of the ultrasonic waveform, shape change of the ultrasonic waveform, ultrasonic attenuation characteristics, and the like.
[0030]
The deterioration diagnosis characteristic may be any characteristic that can indicate the degree of deterioration of the organic polymer material (hereinafter also referred to as “coating layer material”) used for the coating layer and has a correlation with the propagation characteristic. For example, surface rebound hardness, surface penetration hardness, tensile strength, elongation at break, elastic modulus, Young's modulus, modulus, dielectric constant, dielectric loss tangent, volume resistivity, AC breakdown voltage strength, impulse breakdown voltage strength, screw Examples include mechanical characteristics and electrical characteristics such as torsional torque and bending rigidity. In particular, the elongation at break indicates the degree of deterioration of the cable coating layer and has a strong correlation with the propagation characteristics, and is therefore preferably used as a deterioration diagnosis characteristic.
[0031]
Generally, when the elongation at break of the cable covering layer approaches 50%, cracks tend to occur due to vibration or impact, and as a result, there is a possibility of causing dielectric breakdown due to water intrusion from the outside. Therefore, it is considered that the replacement of the cable may be carried out with reference to the elongation at break of about 50%. However, the criterion of the degradation index may be determined by the user as appropriate.
[0032]
The propagation time measuring means may be any device that can measure the propagation time from the transmitting means to the receiving means, and its configuration is not limited. However, as in the example of FIG. 1, a signal indicating that transmission has started from the transmitting means. In response to a signal indicating that the incoming signal has arrived from the receiving means, the calculation of the time between them as a propagation time is simple and accurate. Minor errors that occur due to the interposition of a delay chip may be corrected as necessary.
[0033]
The temperature measuring means measures the surface temperature of the coating layer. As shown in FIG. 1, a good heat conductive member 31 is brought into contact with the surface of the coating layer, and a temperature sensor 32 is attached to this member. In this configuration, the surface temperature of the coating layer is measured via the heat conductive member 31. The temperature measurement means refers to the entire system for measuring temperature, and includes not only the probe section at the tip but also an amplification circuit system that amplifies the detection signal, as with the transmission means.
[0034]
The good heat conductive member may be any material that responds well to the surface temperature of the coating layer and can efficiently transfer heat to the temperature sensor. It may be a structure configured to achieve thermal conductivity. The good thermal conductivity in the present invention means that the thermal conductivity in the vicinity of room temperature is approximately 100 W / m · K or more. As a mode that can be easily formed into a member having an appropriate heat capacity at a low cost, a mode in which a generally known heat conductive metal material is used and a plate shape or a lump shape is preferable. As such a metal, copper, a copper alloy, aluminum, or an aluminum alloy is preferable. The plate-like embodiment has an advantage that it can be easily processed and the heat capacity can be easily adjusted by area, while the bulk-like embodiment such as a columnar shape, a prismatic shape, a conical shape, or a pyramid shape has a heat capacity by volume. There is an advantage that the sensor can be adjusted and the sensor can be reduced in size as a whole by reducing the contact surface with the cable.
[0035]
In the case where the heat conductive member has the above plate shape, for example, when the plate surface is square, the size is preferably about 2 mm × 2 mm to 10 mm × 10 mm, and the plate thickness is preferably about 0.1 mm to 2 mm. In the case of a lump, for example, in the case of a cylinder, the size of the contact surface is preferably about 2 mm to 10 mm in diameter, and the height of the cylinder is preferably about 2 mm to 10 mm. In order to adjust the heat capacity, there is no problem even if it is out of the above range, and any shape may be used. The contact surface may be a curved surface along the cable. The contact between the coating layer and the good heat conductive member may be a contact only at the time of measurement or a permanent fixation.
[0036]
The temperature sensor is not particularly limited, and a known temperature measurement sensor may be used. For example, a thermocouple, a platinum resistance thermometer, a thermistor, etc. are mentioned. As described above, a circuit unit necessary for necessary detection may be an integrated type or a separated type.
[0037]
The arrangement relation of the probe means of the transmitting means, the receiving means, and the temperature measuring means to the cable is not limited, but in order to propagate ultrasonic waves linearly along the surface of the coating layer, the transmitting means and the receiving means are arranged in the longitudinal direction of the cable. It is preferable to arrange | position along. On the other hand, it is preferable that the temperature measuring means is located in the vicinity so as not to obstruct the propagation of ultrasonic waves. In the example of FIG. 1, the transmission means, the reception means, and the temperature measurement means are arranged on a straight line along the longitudinal direction of the cable.
[0038]
As described in the above description of the operation, the cable deterioration diagnosis method using ultrasonic waves is a method of obtaining a corresponding deterioration diagnosis characteristic from the value of the propagation characteristic. Therefore, in order to immediately determine the degree of deterioration at the site, the relationship between the propagation characteristics and the deterioration diagnosis characteristics is obtained in advance for various organic polymer materials of different coating layers depending on the type of cable. It should be possible to convert from propagation characteristics to degradation diagnosis characteristics in the field. The conversion of the propagation characteristics / diagnostic characteristics may be performed manually using a correlation graph or the like, but an arithmetic unit having a deterioration diagnosis data group corresponding to propagation characteristics and diagnostic characteristics for various materials of the coating layer is provided. It is quick and accurate to provide a configuration in which the diagnostic characteristics are automatically obtained from the propagation characteristics. The propagation characteristics may be manually input, but a mode in which the propagation characteristics are directly connected to each means is preferable.
[0039]
The calculation unit converts at least the propagation characteristic into the diagnostic characteristic. As shown in FIG. 1, the calculation unit controls the transmission unit, the reception unit, the propagation time measurement unit, and the temperature measurement unit to obtain the propagation time, and corrects the temperature. However, if necessary, the control unit itself may be configured to perform the operation until conversion to other propagation characteristics such as propagation speed and selection of deterioration diagnosis characteristics from the deterioration diagnosis data group. A computer is the most suitable device.
[0040]
The degradation diagnosis data group may be continuous such that an empirical formula for conversion is used, or may be discrete that is a collection of corresponding data. In addition, the deterioration diagnosis data group is not only that the “propagation characteristics” and the “diagnosis characteristics” correspond to each other in a binary manner, but adds an element of “elapsed time” to these, and “elapsed time” A data group in which “diagnostic characteristics” and “propagation characteristics” correspond three-way may be used. Furthermore, a data group corresponding to multiple factors may be added by adding other elements.
[0041]
By adding “time passage” as an element to the data group, it is not only possible to determine the mechanical and electrical characteristics of the coating layer, but also to change the diagnostic characteristics over time from changes in the propagation characteristics over time. And comprehensive diagnosis including evaluation related to the passage of time, such as estimation of remaining life (residual life). In particular, the estimation of the remaining life is not a deterioration up to the time of measurement, but a diagnosis of the progress of the deterioration after the time of measurement, and is a useful deterioration diagnosis for equipment such as cables.
[0042]
As described in the above description of the operation, in the present invention, in order to improve the workability of the inspector at the maintenance site and stabilize the measurement, a cable holder is provided at the distal end portion of the diagnostic apparatus. FIG. 2A is an example thereof, and a groove 6 is provided in the receiving member 7, and the cable C is sandwiched and held between the groove 6 and the probe portion 4.
[0043]
The internal structure of the probe portion 4 of the cable holder shown in FIG. 2A is the same as that shown in FIG. As shown in FIG. 2B, the transmitter chip, the delay chips 11 and 12 of the receiving means, and the heat conductive member 31 of the temperature measuring means are exposed on the contact surface of the probe unit 4.
[0044]
It is preferable to provide a slip stopper for the cable to be held on the surface of the groove 6 of the cable holder to ensure the holding of the cable. The mode of the anti-slip is not limited, but, for example, a mode in which various surface roughening processes such as grooving and knurling are performed on the surface of the groove, a mode in which a layer made of an elastic material such as rubber is provided on the surface of the groove, etc. Can be mentioned. Further, a part or the whole of the receiving member 7 having the groove 6 may be made of an elastic material. It is also effective to perform the roughening process on the groove surface made of an elastic material.
[0045]
The cross-sectional shape of the groove is not limited in any shape, but is preferably V-shaped or U-shaped in terms of stability and ease of gripping of various sizes of electric cables.
[0046]
As a structure of the entire cable holder, as shown in FIG. 2A, a structure in which the cable is sandwiched between the probe portion 4 and the receiving member 7 by the restoring force of the elastic body 8 is preferable. As a result, the transmission means, the reception means, and the temperature sensor can always be brought into stable contact with the surface of the cable covering layer with a constant load.
[0047]
The elastic body is preferably various springs in that the load can be easily set, but may be a mass of an elastic material such as rubber. The restoring force of the elastic body may be due to any displacement such as compression, pulling, twisting and bending. Moreover, there is no restriction | limiting in particular in the mechanism which clamps a cable using the force of an elastic body. 2A, the two levers L1 and L2 are coupled in a link shape at the fulcrum portion 9, and the force of the compression coil spring 8 is applied to sandwich the cable C like a clothespin. .
[0048]
Regarding the basic technique of ultrasonic deterioration diagnosis for obtaining the degree of deterioration from the propagation characteristics of the coating layer, the organic polymer material constituting the coating layer, the relationship between the propagation characteristics and the deterioration diagnosis characteristics, etc. Reference may be made to JP-A-7-35373, JP-A-10-54827, JP-A-10-300731, and JP-A-11-14607.
[0049]
【Example】
In this embodiment, an ultrasonic deterioration diagnosis apparatus having the cable holder of the mode shown in FIG. 2 is manufactured, and specifications of each part of the cable holder, that is, (1) material of a good heat conductive member, (2) good The shape of the heat conductive member, (3) the cross-sectional shape of the groove of the cable holder, (4) the surface material of the groove surface, and (5) the roughening of the groove surface, The responsiveness of temperature measurement on the surface of the coating layer, the stability of the temperature measurement value, and the cable gripping stability were investigated.
In addition, as a comparative example, a material with a good heat conductive member removed, a material with poor heat conductivity instead of a good heat conductive member, and a groove surface material that is hard and non-slip were manufactured. .
[0050]
The low-voltage cable for railway to be measured is a 600V 3-core vinyl insulated vinyl sheath cable VVR 5.5 mm as defined in JIS C 3342.²However, it was laid outdoors. The temperature at the time of measurement was 27 ° C.
[0051]
As the shape of the good heat conductive member of the temperature measuring means, a cylindrical shape having a diameter of 4 mm and a height of 4 mm and a plate shape having an outer shape of 5 mm × 5 mm and a thickness of 1 mm were used as an example of a lump. A platinum resistance thermometer was used for the temperature sensor.
[0052]
The responsiveness of the temperature measurement was evaluated by the time until the indicated value of the thermocouple thermometer separately installed to make the temperature measurement value coincide with the reference for determination. The thermocouple thermometer was fixed to the surface of the coating layer 30 mm away from the measurement point with an insulating tape, and a sufficiently long time was allowed to pass so as to show the correct surface temperature of the coating layer.
[0053]
The stability of the temperature measurement value was evaluated based on the temperature fluctuation range for 1 minute after the temperature measurement value matched the indicated value of the thermocouple thermometer.
[0054]
With respect to the stability of gripping the cable, the cable laid in the vertical direction and the horizontal direction was gripped by the cable holder, and it was observed whether or not the contact portion was displaced when the hand was released.
[0055]
Table 1 shows the changes in the specifications of the cable holders in the diagnostic devices manufactured as examples and comparative examples. In Table 1, among the symbols indicating the material of the heat conductive member, “Al alloy” is the aluminum alloy for extension (6061) specified by JIS, “SUS” is stainless steel (SUS304) specified by JIS, and “Brass” Represents JIS-defined 60/40 brass (C2801), “PE” represents polyethylene, and “PVC” represents polyvinyl chloride.
In the roughening process on the groove surface, “R” indicates knurling, “SB” indicates sand blasting, and “G” indicates grooving.
[0056]
[Table 1]

[0057]
Table 2 shows the evaluation of cable holders manufactured as examples and comparative examples.
In Table 2, regarding the responsiveness of the temperature measurement, the number of seconds required for the response is divided into four stages, the response within 10 seconds is “」 ”, the response within 15 seconds is“ ◯ ”, the response within 30 seconds is“ △ ”, 31 Seconds or more are indicated by “x”.
Also, regarding the stability of temperature measurement values, the temperature fluctuation range is divided into four stages: “◎” for fluctuations within 1 ° C, “O” for 2 ° C or less, “△” for 4 ° C or less, 5 ° C or more. It is indicated by “x”.
Regarding the cable gripping stability, the observation results are divided into four stages, with no deviation indicated by “ず れ”, slight deviation indicated by “◯”, large deviation indicated by “△”, and drop indicated by “×”. .
[0058]
[Table 2]

[0059]
As shown in Table 2, it was found that the device of the present invention provided with a good heat conductive member responded more promptly to the surface temperature of the cable and was more stable than the comparative example not provided. In addition, in terms of the operability of the cable holder, in the embodiment of the present invention in which the groove surface is provided with a non-slip, the temperature sensor is removed from the surface of the coating layer even if the hand is released by simply pinching the cable with the force of the spring. There was no deviation. From this, it was found that accurate deterioration diagnosis is possible even in places where it is difficult to hold the diagnostic device by hand with respect to the cable, such as high places and narrow parts.
[0060]
【The invention's effect】
As described above, the ultrasonic degradation diagnosis apparatus of the present invention can measure the surface temperature of the coating layer accurately and quickly at the site where a low-voltage cable for railways is laid, although it has a simple configuration. Therefore, accurate temperature correction can be performed on the spot with respect to the measured ultrasonic wave propagation characteristics, and hence accurate and rapid deterioration diagnosis can be performed.
In addition, since the ultrasonic degradation diagnosis apparatus of the present invention is equipped with a cable holder suitable for use at the maintenance site of railway facilities, it improves the workability of the inspector and enables accurate and rapid degradation diagnosis. It has become.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration example of an ultrasonic deterioration diagnosis apparatus according to the present invention.
FIG. 2 is a schematic diagram showing a configuration example of a cable holder attached to the ultrasonic deterioration diagnosis apparatus in the present invention. FIG. 2A shows a state in which the cable C is sandwiched. The cable C intersects perpendicularly with the paper surface. FIG.2 (b) is the perspective view which showed the contact surface with respect to the cable of the probe part 4 of the cable holder shown to Fig.2 (a).
[Explanation of symbols]
1 Ultrasonic transmission means
2 Ultrasonic wave receiving means
3 Temperature measurement means
31 Good thermal conductive material
32 Temperature sensor
4 Probe section
5 Control unit
C Low-voltage cable for railway
C1 coating layer
W Ultrasound

Claims (6)

An ultrasonic degradation diagnosis device for diagnosing a low-voltage electric cable for railway equipment having a coating layer made of an organic polymer material,
The apparatus includes: an ultrasonic transmission unit; an ultrasonic reception unit; a propagation time measurement unit that measures a propagation time when ultrasonic waves propagate through the coating layer from the transmission unit to the reception unit; Temperature measuring means for measuring the surface temperature,
The ultrasonic transmission means, the ultrasonic reception means and the temperature measurement means are each separated into a probe part and a control part,
The temperature measuring means has, as a probe part , a heat conductive member for contacting the surface of the coating layer, and a temperature sensor attached to the member ,
The probe parts of the ultrasonic transmission means, the ultrasonic reception means, and the temperature measurement means are combined into one probe part,
Furthermore, the device has a cable holder,
The cable holder has a structure in which two levers are linked in a link at the fulcrum, and the low-voltage cable is sandwiched by the restoring force of an elastic body,
A probe portion combined with the one and a receiving member for receiving the cable are provided in a portion sandwiching the cable, and a groove is provided in the receiving member, and the groove and the one are combined. The structure is such that the cable can be held between the probe portion and the probe portion of the ultrasonic transmission means, the ultrasonic reception means, and the temperature measurement means, and the probe portion is fixed on the surface of the coating layer in a state where they are united together. An ultrasonic deterioration diagnosis device for a low-voltage electric cable for railway equipment, characterized in that it can be contacted by a load .   The ultrasonic transmission means is configured to be able to install an ultrasonic oscillator on the surface of the coating layer via a delay chip,
  The ultrasonic receiving means is configured to be able to install an ultrasonic detection element via a delay chip at a position away from the ultrasonic transmitting means by a predetermined distance on the surface of the coating layer,
  Of the probe unit combined into one, the surface contacting the coating layer is exposed to the delay chip of the ultrasonic transmission means, the delay chip of the ultrasonic reception means, and the good heat conductive member of the temperature measurement means. The ultrasonic deterioration diagnostic apparatus according to claim 1.   2. The ultrasonic deterioration diagnosis apparatus according to claim 1, wherein the good heat conductive member is made of copper, a copper alloy, aluminum, or an aluminum alloy. Furthermore, it has a calculation part,
The calculation unit has a deterioration diagnosis data group in which the ultrasonic propagation characteristic and the deterioration diagnosis characteristic correspond to the material of the coating layer, and the ultrasonic propagation characteristic including the propagation time is obtained from the temperature obtained by the temperature measuring unit. 2. The ultrasonic deterioration diagnosis apparatus according to claim 1, wherein the ultrasonic deterioration diagnosis apparatus performs temperature correction using the deterioration diagnosis data group and calculates a deterioration diagnosis characteristic of the coating layer. The ultrasonic deterioration diagnosis apparatus according to claim 1, wherein the groove has a non-slip against the low-voltage electric cable to be held on the surface of the groove. The cleat, or those formed by roughened processing is given to the surface of the groove, or, according to claim 5 wherein in which the layer of resilient material on the surface of the groove is provided Ultra Sonic deterioration diagnosis device.

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