JP2001194350A - Ultrasonic degradation diagnostic apparatus for low voltage electric cable for railway facilities - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic degradation diagnostic apparatus capable of accurately and quickly diagnosing the degradation of a low voltage cable for railway facilities with a simple configuration, and suitable for the use at a maintenance site of the railway facilities. SOLUTION: This ultrasonic degradation diagnostic apparatus diagnoses the degradation of the low voltage wire cable C for the railway facilities having a covering layer C1 formed of an organic polymer using the ultrasonic wave. The apparatus comprises an ultrasonic wave transmitting means 1, an ultrasonic wave receiving means 2, a propagation time measuring means (included in a control unit 5 in Fig.1) to measure the propagation time from the transmitting means 1 to the receiving means 2 when the ultrasonic wave W is propagated through the covering layer, and a temperature measuring means 3 to measure the surface temperature of the covering layer. The temperature measuring means 3 comprises a good heat conductor 31 in contact with the surface of the covering layer and a temperature sensor 32 mounted on the member 31. The ultrasonic wave propagation characteristic and the rapid and correct temperature can be measured. A cable holder having slip-proof grooves is used for preferably holding the cable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of diagnosing deterioration of electric wires and cables using ultrasonic waves, and particularly to a low-voltage cable for railway equipment (hereinafter referred to as "low-voltage cable for railway" or (Also called simply "cable")
The present invention relates to a diagnostic device for diagnosing.

[0002]

2. Description of the Related Art A low-voltage railway cable is laid to supply electric power to a large number of facilities and equipment provided along a track, and to supply a signal current for controlling these cables. Playing an important role. Examples of facilities along the railway line include traffic lights and circuit breakers such as railroad crossings, devices related to points, various monitoring devices, control devices, and the like.

[0003] If a problem such as insulation failure due to deterioration occurs in a coating layer of a low-voltage cable for a railway (an insulating layer made of an organic polymer material covering the outer periphery of a conductor), a safe and stable operation of a vehicle or a railway There is a risk that the operation of the entire facility will be affected. For this reason, insulation performance tests are regularly performed on railway low-voltage cables at a higher frequency than general low-voltage cables.

Conventionally, in an insulation performance test for a low-voltage railway cable, the insulation resistance between cables (for example, between cables corresponding to each phase of three-phase alternating current) or the ground is measured electrically, The insulation performance was directly measured by extracting a leakage component by superimposing a frequency current.

[0005]

However, in the conventional diagnostic method as described above, it is necessary to stop the power during the measurement. Since railway equipment is in operation for 24 hours a year, there are many safety problems for inspectors and time constraints for deterioration diagnosis. In order to accurately diagnose the deterioration of the cable within such a limited time, the inspector is required to perform strict inspection work. Also,
There is also a problem that a large-scale facility such as a power supply facility is required for the measurement.

In order to solve the above problems, the present inventors have
First, an attempt was made to diagnose a cable in a live state by applying a deterioration diagnosis method using ultrasonic waves to a low-voltage cable for railways. However, when further examining the embodiment of ultrasonic degradation diagnosis at the maintenance site of railway equipment,
It has been found that the ultrasonic degradation diagnosis has the following problems because it is used for railways.

[0007] Working near or inside train tracks and facilities is dangerous, and it is difficult to ensure the safety of workers during long hours of work. For the above reasons, the diagnosis work is performed with security personnel, so that the labor cost increases when the time is long. The railway track extends over a long distance, and the number of diagnostic points is extremely large even within a specific section. In order to perform ultrasonic diagnostics in various environments along the railway, correction to a specific temperature is required, and therefore, the surface temperature of a cable to be diagnosed must be measured. However, in a control box such as a power supply / electrical box, or in a trough (concrete groove along the railroad track where the electric wires are stored), the control box or trough lid must be closed for diagnosis. The cable temperature changes rapidly due to direct sunlight or outside air. Therefore, if the ultrasonic wave propagation characteristics are not promptly measured, the propagation measurement at the actual temperature cannot be performed. Also, if the cable surface temperature is not measured promptly, the actual temperature cannot be obtained and accurate temperature correction cannot be performed. .

As described above, a rapid measuring operation is required at the maintenance site of railway equipment, and in particular, in order to cope with the above problem, the surface temperature of the coating layer must be measured quickly and accurately. I understand.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to diagnose the deterioration of a low-voltage cable for railways accurately and quickly with a simple facility. It is to provide a device.

[0010]

The ultrasonic degradation diagnosis apparatus of the present invention has the following features. (1) A low-voltage cable for railway equipment having a coating layer made of an organic polymer material is diagnosed, and an ultrasonic transmitting means, an ultrasonic receiving means, and an ultrasonic wave covering the transmitting means to the receiving means. A propagation time measuring means for measuring a propagation time when propagating through the layer; and a temperature measuring means for measuring a surface temperature of the coating layer, wherein the temperature measuring means has good heat conduction for contacting the surface of the coating layer. An ultrasonic degradation diagnostic apparatus for a low-voltage cable for railway equipment, comprising: a flexible member; and a temperature sensor attached to the member.

(2) The ultrasonic deterioration diagnosis apparatus according to the above (1), wherein the good heat conductive member is made of copper, copper alloy, aluminum or aluminum alloy.

(3) The computer further comprises an operation unit, the operation unit having a deterioration diagnosis data group corresponding to the ultrasonic wave propagation characteristics and the deterioration diagnosis characteristics with respect to the material of the coating layer, and including the propagation time. The supersonic wave according to the above (1), wherein the ultrasonic propagation characteristics are temperature-corrected using the temperature obtained by the temperature measuring means, and the calculation for obtaining the deterioration diagnosis characteristics of the coating layer is performed using the deterioration diagnosis data group. Sound wave deterioration diagnosis device.

(4) A cable holder is provided, the cable holder having a groove which can be used for holding the low-voltage cable, and the ultrasonic transmitting means, the ultrasonic receiving means, and the temperature measuring device. The ultrasonic degradation according to the above (1), wherein the low-voltage cable is held between the means and the groove, and a non-slip for the low-voltage cable to be held is provided on the surface of the groove. Diagnostic device.

(5) The non-slip is obtained by subjecting a surface of the groove to a roughening process, or by providing a layer made of an elastic material on the surface of the groove. The ultrasonic deterioration diagnosis apparatus according to the above (4).

[0015]

According to the method for diagnosing deterioration of a cable using ultrasonic waves, the propagation characteristics (propagation speed, propagation time, etc.) of ultrasonic waves in the coating layer change according to the degree of deterioration of the organic polymer material constituting the coating layer. Is used to measure the propagation characteristics,
This is a method of obtaining a corresponding deterioration diagnosis characteristic from the value.

The propagation characteristics (propagation speed, propagation time, etc.) of the ultrasonic wave propagating through the coating layer show temperature dependence and are greatly influenced by the temperature of the coating layer. Those exposed to the outside air or sunlight, such as low-voltage cables for railways, measure the propagation time, and accurately measure the surface temperature of the coating layer.The measurement result of the propagation time is a value at a standard temperature. Must be corrected. In addition, as described in the "Description of Problems to be Solved by the Invention", accurate temperature measurement is difficult unless temperature measurement is quick.

Therefore, in the present invention, a configuration is adopted in which the surface temperature of the coating layer of the cable can be measured, a good heat conductive member is provided at the tip of the temperature sensor, and the temperature is measured via this member. Since the good heat conductive member quickly reaches the surface temperature of the coating layer, the temperature detection unit of the temperature sensor can quickly and accurately detect the temperature of the surface of the coating layer via the good heat conductive member. Further, since the good 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 object to be measured and stability of measurement against temperature disturbance from the outside.

Further, when the operator inspects the measuring operation at the maintenance site, the contact tends to become unstable when the diagnostic device comes into contact with the coating layer of the cable. It was found that the accuracy of the diagnostic results was low. In the present invention, as a more preferred embodiment, using a holder having a groove provided with a non-slip, the ultrasonic transmission means, the ultrasonic receiving means, the temperature measuring means and the like, and the groove of the holder, the cable is securely secured. It was configured to be gripped. This facilitates the measurement operation, stabilizes the contact state between the diagnostic device (particularly, the temperature measuring means) and the coating layer of the cable, and reduces the dispersion of measured values.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ultrasonic degradation diagnostic apparatus according to the present invention, as shown in FIG. 1, shows an ultrasonic transmitting means (hereinafter referred to as "transmitting means") 1 and an ultrasonic receiving means (hereinafter referred to as "receiving means"). ) 2, a propagation time measuring unit (included in the control unit 5 in FIG. 1), and a temperature measuring unit 3. The transmitting means 1, the receiving means 2, and the temperature measuring means 3 are in contact with the surface of the coating layer C1 of the cable C.

The transmitting means 1 sends out the ultrasonic wave W to the coating layer C1 toward the receiving means 2, and the receiving means 2 receives it at a position separated 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 propagation characteristic form, the temperature is corrected, and the value of the deterioration diagnostic characteristic of the coating layer is obtained from the value. In order to perform this temperature correction, a temperature measuring means 3 for measuring the surface temperature of the coating layer is provided. The temperature measuring means 3 has a good heat conductive member 31 for making direct contact with the coating layer, and a temperature sensor 32 attached thereto. With the diagnostic device configured as described above, as described in the above description of the operation,
The temperature correction of the propagation characteristics can be accurately performed, and correct deterioration diagnosis can be performed.

The low-voltage cable for railways to be diagnosed is DC 750 V or less and AC 6
It is an insulated wire for low voltage of 00V or less. The cable is
As shown in FIG. 1, an insulating layer made of an organic polymer material is provided as a coating layer outside the central conducting wire C2. As the organic polymer material, a thermoplastic resin such as polyethylene or polypropylene, a natural or synthetic rubber, a thermoplastic elastomer, or the like is used.

The transmitting means and the receiving means are devices for transmitting and receiving ultrasonic waves using the coating layer as a propagation path. The transmitting means and the receiving means refer not only to the probe part at the tip mounted on the coating layer but also to the entire system for transmitting and receiving ultrasonic waves, respectively, and include an ultrasonic transducer (transmission) and an ultrasonic detection element ( In addition to a conversion element such as reception, a drive circuit system for supplying and amplifying electric energy, a delay chip interposed between the element and the coating layer, and the like are included.

In the example shown in FIG. 1, the overall configuration of the diagnostic apparatus is separated into a probe unit 4 attached to the coating layer and a control unit 5 connected to the probe unit 4 by wire (or wirelessly). , Transmitting means 1, receiving means 2, temperature measuring means 3,
Each is separated into a probe unit and a control unit. For example, in the transmission means 1, the delay chip 11 and the conversion element 1
2 is included in the probe unit 4 and its driving circuit system is a control unit 5
Included in. However, not only such a separated type, but also an embodiment in which the drive circuit system and the probe unit are integrated, the integrated type and the separated type in each means can be freely selected for each means. Good. Further, in the example of FIG. 1, the probe units of the transmitting unit 1, the receiving unit 2, and the temperature measuring unit 3 are combined into one probe unit 4 in terms of preferable operability, but only the temperature measuring unit 3 is used. For example, the integration and separation of the respective means may be freely selected, such as an embodiment in which the means are independent.

The method of transmitting and receiving the ultrasonic wave includes a method of emitting an ultrasonic wave in an inward direction perpendicular to the surface of the coating layer and receiving a wave reflected at a deep layer at the same position, and a method of transmitting the ultrasonic wave obliquely downward from the surface of the coating layer. Various known techniques may be used, such as a method of emitting a sound wave, reflecting the sound wave in a deep layer, and receiving the sound wave at a remote position. Above all, the method of directly transmitting ultrasonic waves to the receiving means along the surface of the coating layer using a delay chip is a method in which the propagation velocity can be calculated only by the amount that can be clearly measured from the outside [time, linear distance]. It is. Hereinafter, the present invention will be described with respect to a transmitting unit, a receiving unit, a propagation time measuring unit, and the like, taking as an example a mode in which an ultrasonic wave is propagated along a surface of a coating layer using a delay chip.

As shown in FIG. 1, in the transmitting means 1, the ultrasonic oscillator 12 is provided with a coating layer C via a delay chip 11.
1 surface. In the receiving means 2, the ultrasonic detecting element 22 is connected to the coating layer C via the delay chip 21.
1 is installed at a position separated from the transmitting means 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 the ultrasonic wave propagation velocity 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 light propagates linearly along the surface of the layer (that is, through and near the surface of the coating layer) 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.

The delay chip is interposed between the conversion element and the coating layer. The delay chip refracts the propagation direction of the ultrasonic wave, sends the ultrasonic wave along the surface of the coating layer, and propagates the ultrasonic wave along the surface. It is configured to accept incoming ultrasonic waves. The basic structure of the delay chip may refer to the prior art.

The surface of the coating layer through which the ultrasonic waves propagate and the vicinity of the surface mainly include a region from the surface of the coating layer to a depth of about 3 mm. Therefore, although there is no problem when the coating layer is sufficiently thick, for example, when the thickness is only 1.5 mm, a part of the ultrasonic wave is transmitted to the next layer below the coating layer (such as a conductor in a cable). ), Or the reflection is repeated between the interface and the surface of the coating layer, so that the propagation characteristics may not be accurately measured. Therefore, in order to measure more accurately, for example, the ultrasonic wave is propagated to the surface of the coating layer and to a depth of about 1 mm from the surface, and a linear transmission from the transmitting means to the receiving means is performed at a depth that does not reach the lower layer. Preferably.

The frequency of the ultrasonic wave used in the present invention is not limited. In addition, since organic polymer materials, such as polyethylene, polyvinyl chloride, and ethylene-propylene copolymer rubber (EPM), which are frequently used for a coating layer of a cable, generally have a large attenuation of ultrasonic waves, the attenuation is relatively small. ~ 5M
A frequency of about Hz, particularly about 0.5 to 2 MHz is preferable.

The propagation characteristic may be an amount that indicates the propagation state when the ultrasonic wave is propagated through the material of the coating layer and has a correlation with the deterioration of the material. For example, in addition to particularly useful propagation time and propagation velocity, ultrasonic reception sensitivity, frequency change of ultrasonic waveform, shape change of ultrasonic waveform,
Ultrasonic attenuation characteristics and the like.

The deterioration diagnostic characteristic is a characteristic that can indicate the degree of deterioration of the organic polymer material used for the coating layer (hereinafter, also referred to as “material of 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, Mechanical characteristics and electrical characteristics such as torsion torque and bending rigidity are given. In particular, since the elongation at break significantly indicates the degree of deterioration of the coating layer of the cable and has a strong correlation with the propagation characteristics, it is preferably used as a deterioration diagnostic characteristic.

In general, when the elongation at break of the coating layer of the cable approaches 50%, cracks tend to occur due to vibration or impact, and as a result, dielectric breakdown may occur due to invasion of water from the outside. . Therefore, it is considered that the replacement of the cable may be performed with reference to the elongation at break of about 50%. However, the criterion of the deterioration index may be appropriately determined by the user.

The propagation time measuring means may be any device capable of measuring the propagation time from the transmitting means to the receiving means, and its configuration is not limited. However, as shown in the example of FIG. Receiving the signal indicating that the signal has been received, and receiving the signal indicating that the call has arrived from the receiving means, counting the time during that time and calculating the propagation time is simple and accurate. Minor errors that occur due to the presence of a delay chip may be corrected as needed.

The temperature measuring means is for measuring 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. Is attached, and the surface temperature of the coating layer is measured via the good heat conductive member 31. The temperature measuring means refers to the entire system for measuring temperature, and includes not only a probe section at the tip but also an amplification circuit system for amplifying a detection signal, as in the case of the transmitting means.

The good heat conductive member may be any material that responds well to the surface temperature of the coating layer and can efficiently transmit heat to the temperature sensor. In addition, the structure may be configured to achieve high thermal conductivity. Good thermal conductivity in the present invention means that the thermal conductivity near normal temperature is about 100 W / m · K or more. As a mode that can be easily formed at low cost into a member having an appropriate heat capacity, a mode in which a generally known metal material having good heat conductivity is used and a plate shape or a block shape is preferable.
Preferred such metals include copper, copper alloys, aluminum or aluminum alloys. The plate-like aspect has an advantage that processing is easy and the heat capacity can be easily adjusted by the area.On the other hand, the column-like, prismatic, conical, and pyramid-like massive aspects have the heat capacity by volume. There is an advantage that the sensor can be adjusted, the contact surface with the cable can be reduced, and the sensor can be downsized as a whole.

When the good heat conductive member has the above-mentioned plate shape, for example, when the plate surface is square, the size is 2 mm × 2 mm to
The thickness is preferably about 10 mm × 10 mm, and the thickness is preferably about 0.1 mm to 2 mm. Also, in the case of a lump, for example, in the case of a cylinder, the size of the contact surface is about 2 mm to 10 mm in diameter,
The height of the cylinder is preferably about 2 mm to 10 mm. To adjust the heat capacity, there is no problem even if it is out of the above range, and any shape may be used. Further, 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.

The temperature sensor is not particularly limited, and a known temperature measuring sensor may be used. For example, a thermocouple, a platinum resistance thermometer, a thermistor, and the like can be given. As mentioned above,
The circuit part necessary for the necessary detection may be of an integrated type or a separated type.

The arrangement of the transmitting means, the receiving means, and the temperature measuring means with respect to the cable of each probe unit is not limited. However, in order to transmit ultrasonic waves linearly along the surface of the coating layer, the transmitting means and the receiving means must be connected by a cable. Are preferably arranged along the longitudinal direction. On the other hand, it is preferable that the temperature measuring means is located in such a vicinity as not to hinder the propagation of the ultrasonic wave. In the example of FIG. 1, the transmitting unit, the receiving unit,
The temperature measuring means is arranged in a straight line along the longitudinal direction of the cable.

As described in the above description of the operation, the method for diagnosing deterioration of a cable by 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 in the field, the relationship between the propagation characteristics and the deterioration diagnostic characteristics of the organic polymer materials of various coating layers that differ depending on the type of cable is determined in advance, and on the spot. It should be possible to convert from propagation characteristics to degradation diagnostic characteristics. Although the conversion of the propagation characteristics / diagnosis characteristics may be performed manually using a correlation graph or the like, the present invention employs an arithmetic unit having a deterioration diagnosis data group in which the propagation characteristics and the diagnosis characteristics correspond to various materials of the coating layer. 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.

The arithmetic unit converts at least the propagation characteristic into a diagnostic characteristic. As shown in FIG. 1, the operation unit controls the transmitting means, the receiving means, the propagation time measuring means, and the temperature measuring means to calculate the propagation time. Alternatively, the control unit itself may perform temperature correction, if necessary, conversion to another propagation characteristic such as a propagation speed, and intensively perform the operation of selecting the deterioration diagnosis characteristic from the deterioration diagnosis data group. A computer is most suitable as the device.

The deterioration diagnosis data group may be a continuous data group using an empirical formula for conversion or a discrete data group obtained by collecting corresponding data. In addition, the deterioration diagnosis data group includes:
In addition to making the “propagation characteristic” and “diagnosis characteristic” correspond in a binary manner, an element of “elapse of time” is added to them, and “elapse of time”, “diagnosis characteristic”, and “propagation characteristic” May be a data group corresponding to the three elements. Further, the data group may be a multi-dimensional data group by adding other elements.

By adding “elapse of time” as an element to the data group, it is possible not only to judge the values of the mechanical characteristics and the electric characteristics of the coating layer, but also to determine the diagnostic characteristics based on the temporal change of the propagation characteristics. It is possible to know the change with time, and it is possible to perform a comprehensive diagnosis including evaluation relating to the passage of time, such as estimation of the remaining life (remaining life). In particular, the estimation of the remaining life is not for deterioration up to the measurement time point, but for diagnosing the progress of deterioration after the measurement time point, and is a useful deterioration diagnosis for equipment such as cables.

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 of the diagnostic device. I have. FIG. 2A shows an example of such a structure, in which a groove 6 is provided in a receiving member 7, and the cable C is held between the groove 6 and the probe section 4 and held.

The internal structure of the probe part 4 of the cable holder shown in FIG. 2A is the same as that shown in FIG. As shown in FIG. 2B, on the contact surface of the probe part 4, the delay chips 11, 12 of the transmitting means and the receiving means, and the good heat conductive member 31 of the temperature measuring means are exposed.

It is preferable that the surface of the groove 6 of the cable holder is provided with a non-slip for the cable to be held to ensure the holding of the cable. The mode of the non-slip is not limited, and examples thereof include a mode in which various surface roughening processes such as grooving and knurling are performed on the surface of the groove, and a mode in which a layer made of an elastic material such as rubber is provided on the surface of the groove. No. 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 apply the above roughening process to the groove surface made of an elastic material.

There is no limitation on the cross-sectional shape of the groove, but a V-shape or a U-shape is preferable in terms of stability and ease of holding various sizes of electric cables.

The structure of the entire cable holder is shown in FIG.
As shown in (a), a structure in which the cable is sandwiched between the probe unit 4 and the receiving member 7 by the return force of the elastic body 8 is preferable. Thus, the transmitting means, the receiving means, and the temperature sensor can be stably brought into constant contact with the surface of the coating layer of the cable with a constant load.

The elastic body is preferably made of various springs in that the load can be easily set, but may be a lump of an elastic material such as rubber. The return force of the elastic body is compressed, pulled,
Any displacement such as twisting or bending may be used. Further, there is no particular limitation on a mechanism for sandwiching the cable by using the force of the elastic body. 2A, the two levers L1 and L2 are connected in a link at a fulcrum 9, and the force of the compression coil spring 8 is applied to sandwich the cable C like a clothespin. .

The basic technology 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, and the like are described in Japanese Patent Application Laid-Open No. H10-260,086. JP-A-7-35372, JP-A-Hei 7
JP-A-35373, JP-A-10-54827,
JP-A-10-30731, JP-A-11-146
07 publication may be referred to.

[0049]

EXAMPLE In this example, an ultrasonic deterioration diagnosis apparatus having a cable holder of the embodiment shown in FIG. 2 was manufactured, and the specifications of each part of the cable holder, that is, the material of the good heat conductive member,
Response of temperature measurement on the surface of the coating layer of the cable by variously changing the shape of the good thermal conductive member, the cross-sectional shape of the groove of the cable holder, the surface material of the groove surface, and the surface roughening process for the groove surface The stability, the stability of the measured temperature value, and the gripping stability of the cable were examined. In addition, as comparative examples, those having the good heat conductive member removed, those using a material having poor heat conductivity instead of the good heat conductive member, and those having a non-slip surface material with a hard groove surface were manufactured. .

The low-voltage cable for railways to be measured is JIS
A 600 V 3-core vinyl insulated vinyl sheathed cable VVR 5.5 mm ² defined in C3342, which is laid outdoors. The temperature at the time of measurement was 27 ° C.

The shape of the good heat conductive member of the temperature measuring means is as follows.
As an example of a lump, a columnar 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. A platinum resistance temperature detector was used as the temperature sensor.

The responsiveness of the temperature measurement was evaluated by the time until the measured value coincides with the indicated value of a thermocouple thermometer separately provided as a reference for determination. Thermocouple thermometer
It 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 had elapsed so as to show the correct surface temperature of the coating layer.

The stability of the measured temperature value was evaluated based on the temperature fluctuation width for one minute after the measured temperature value coincided with the indicated value of the thermocouple thermometer.

The holding stability of the cable was evaluated by observing whether or not the contact portion was displaced when the cable laid in the vertical direction and the horizontal direction was held by the cable holder and the hand was released.

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 good heat conductive member, "Al alloy" is an aluminum alloy for spreading (6061) specified by JIS, "SUS" is stainless steel (SUS304) specified by JIS, and "brass". Is 60/4 specified by JIS
0 brass (C2801), “PE” is polyethylene, “P”
"VC" indicates polyvinyl chloride. In the roughening process for the groove surface, “R” indicates knurling, “SB” indicates sandblasting, and “G” indicates grooving.

[0056]

[Table 1]

Table 2 shows the evaluations of the 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 was divided into four stages,
A response within 0 seconds is indicated by “◎”, a response within 15 seconds is indicated by “○”, a response within 30 seconds is indicated by “△”, and a response over 31 seconds is indicated by “×”. For the stability of the measured temperature, the temperature fluctuation range is divided into four steps: “◎” for fluctuations within 1 ° C, “○” for fluctuations within 2 ° C, “△” for fluctuations within 4 ° C, It is indicated by "x". Regarding the gripping stability of the cable, the observation results were divided into four stages, and "無 し" indicates no deviation, "○" indicates a slight deviation, "△" indicates a large deviation, and "X" indicates a drop. .

[0058]

[Table 2]

As shown in Table 2, it is clear that the device of the present invention provided with the good heat conductive member responds more quickly to the surface temperature of the cable and is more stable than the comparative example without the device. became. In addition, in terms of operability of the cable holder, in the case of the present embodiment in which the groove surface is non-slip, the temperature sensor can be removed from the surface of the coating layer even if the hand is released only by holding the cable by the force of the spring. There was no deviation. From this, it has been found that accurate degradation diagnosis is possible even in a place where the diagnostic device is difficult to hold by hand with respect to the cable, such as a high place or a narrow portion.

[0060]

As described above, the ultrasonic deterioration diagnosis apparatus of the present invention can accurately and quickly measure the surface temperature of the coating layer at the site where the low-voltage cable for railway is laid, while having a simple configuration. Accordingly, accurate temperature correction can be performed on the measured ultrasonic wave propagation characteristics on the spot, and accurate and quick deterioration diagnosis can be performed. In addition, since the ultrasonic deterioration diagnosis apparatus of the present invention is equipped with a cable holder suitable for use at the maintenance site of railway equipment, the workability of inspectors can be improved, and accurate and quick deterioration diagnosis can be performed. It has become.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a configuration of an ultrasonic degradation diagnosis apparatus according to the present invention.

FIG. 2 is a schematic view showing a configuration example of a cable holder provided to the ultrasonic degradation diagnosis apparatus according to the present invention. FIG.
(A) shows a state where the cable C is sandwiched. Cable C intersects perpendicularly with the paper. FIG. 2B is a perspective view showing a contact surface of the probe part 4 of the cable holder shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic transmitting means 2 Ultrasonic receiving means 3 Temperature measuring means 31 Good thermal conductive member 32 Temperature sensor 4 Probe part 5 Control part C Low-voltage cable for railway C1 Coating layer W Ultrasonic

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuo Kawabe 2-2-2 Yoyogi, Shibuya-ku, Tokyo East Japan Railway Company F-term (reference) 2G015 AA27 CA20 2G047 AA08 AB03 AB05 BC02 BC11 EA09 EA10 GA18

Claims (5)

[Claims] An object of the present invention is to diagnose a low-voltage cable for railway equipment having a coating layer made of an organic polymer material, and to transmit ultrasonic waves to an ultrasonic transmitting unit, an ultrasonic receiving unit, and an ultrasonic wave from the transmitting unit to the receiving unit. A propagation time measuring means for measuring a propagation time when the light propagates through the coating layer; and a temperature measuring means for measuring a surface temperature of the coating layer, wherein the temperature measuring means is in good contact with the surface of the coating layer. An ultrasonic degradation diagnostic device for a low-voltage cable for railway equipment, comprising a heat conductive member and a temperature sensor attached to the member. 2. The ultrasonic deterioration diagnosis apparatus according to claim 1, wherein the good thermal conductive member is made of copper, copper alloy, aluminum or aluminum alloy. 3. An operation unit, further comprising: a deterioration diagnosis data group in which the ultrasonic wave propagation characteristics and the deterioration diagnosis characteristics of the material of the coating layer correspond to each other. 2. The ultrasonic wave deterioration according to claim 1, wherein the sound wave propagation characteristics are temperature-corrected using the temperature obtained by the temperature measuring means, and the deterioration diagnosis characteristics of the coating layer are calculated using the deterioration diagnosis data group. Diagnostic device. 4. A cable holder, the cable holder having a groove that can be used to hold the low-voltage cable, and the ultrasonic transmitting unit, the ultrasonic receiving unit, and the temperature measuring unit. The ultrasonic degradation diagnostic apparatus according to claim 1, wherein the low-voltage cable is held between the low-voltage cable and the groove, and a non-slip for the low-voltage cable to be held is provided on the surface of the groove. . 5. The non-slip device according to claim 1, wherein the surface of the groove is roughened, or a layer made of an elastic material is provided on the surface of the groove. Item 7. The ultrasonic degradation diagnosis apparatus according to Item 4.