JP6336405B2 - Cross-sectional area change detection device - Google Patents

Description

  The present invention relates to a technique for accurately detecting a change in the cross-sectional area of a steel material, and more particularly to an apparatus for detecting a change in cross-sectional area.

  Conventionally, the overhead wire passing between the utility poles is a steel material, and it is necessary to reinforce or replace when the strength decreases due to corrosion. The number of steel materials such as overhead wires actually installed is enormous, and the amount of inspection work is enormous.

  When steel is corroded, the cross-sectional area changes. Conventionally, for example, the outer diameter of a steel material is measured with calipers or the like, the cross-sectional area is calculated from the outer diameter, and the presence or absence of corrosion is detected based on the change in the cross-sectional area. Further, when the cross-sectional area changes, the electrical resistance value changes. Conventionally, for example, the resistance value of a steel material is measured, and the presence or absence of corrosion is detected based on a change in the resistance value.

"Corrosion", [online], [searched on November 18, 2014], Internet <URL: http://en.wikipedia.org/wiki/%E8%85%90%E9%A3%9F>

  However, for example, since the overhead line is at a high place, it is necessary to move to the location of the overhead line with a bucket car and use calipers or the like at the high place. When working on a bucket car, sometimes it is forced to take an unreasonable posture and there is a possibility that accurate measurement cannot be performed.

  On the other hand, in order to measure the resistance value of the steel material, it is necessary to bring the electrode into contact with the steel material. In this case, it is not easy to make the contact resistance between the steel material and the electrode constant, and there is a possibility that accurate measurement cannot be performed.

  This invention is made | formed in view of said subject, The place made into the objective is providing the technique which detects the change of the cross-sectional area of steel materials correctly.

  In order to solve the above-described problems, a cross-sectional area change detection device according to the present invention includes a cylindrical body surrounding a steel material, and a bag body in an inflated state having a bag body portion that is tightly sandwiched between the steel material and the cylindrical body. And each point in order to measure the resistance value between the two points across the cross section in the bag portion that changes according to the cross-sectional area of the bag portion that changes due to the change in the cross-sectional area of the steel material. It is characterized by comprising an electrode to be provided, and a conductor provided integrally or separately for each electrode, electrically connected to the electrode and drawn out of the bag body.

  According to the present invention, a tubular body surrounding a steel material, a swelled bag body having a bag body portion in close contact with the steel material and the tubular body, and the bag changing due to a change in a cross-sectional area of the steel material An electrode provided at each point in order to measure a resistance value between two points sandwiching the cross section in the bag body portion, which changes according to the cross-sectional area of the body portion, Since a change in resistance value reflects a change in the cross-sectional area of the steel material by providing a conductor that is provided separately and electrically connected to the electrode and drawn out of the bag body, the change in the cross-sectional area of the steel material It can be detected accurately.

  For example, the cross-sectional area change detection device includes two or more of the bags, and includes the two electrodes and the two conductors for each of the bags.

  With this feature, the bag body is not bent (distorted), the degree of adhesion can be increased, and a change in the cross-sectional area of the steel material can be detected more accurately.

  For example, the cross-sectional area change detecting device affects the degree of close contact of the bag body portion to be constant when the resistance value is constant when there is no change in the cross-sectional area of the steel material. An internal pressure detector for detecting the internal pressure is provided.

  With this feature, the internal pressure can be determined. Therefore, it is only necessary to keep the detected internal pressure constant in each resistance measurement, that is, to keep the degree of adhesion constant. The value can be the same. That is, the change in the resistance value correctly reflects the change in the cross-sectional area, so that the change in the cross-sectional area can be correctly detected.

  According to the present invention, a tubular body surrounding a steel material, a swelled bag body having a bag body portion in close contact with the steel material and the tubular body, and the bag changing due to a change in a cross-sectional area of the steel material An electrode provided at each point in order to measure a resistance value between two points sandwiching the cross section in the bag body portion, which changes according to the cross-sectional area of the body portion, Since a change in resistance value reflects a change in the cross-sectional area of the steel material by providing a conductor that is provided separately and electrically connected to the electrode and drawn out of the bag body, the change in the cross-sectional area of the steel material It can be detected accurately.

It is a figure which shows an example of the system containing the apparatus for a cross-sectional area change detection which concerns on this Embodiment. It is an AA arrow directional view of FIG. FIG. 3A is a schematic diagram when two bag bodies 2 are used for one steel material 10, and FIG. 3B shows one bag body 2 used for one steel material 10. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a system including a cross-sectional area change detection device according to the present embodiment. FIG. 2 is a view taken along the line AA in FIG.

  The steel material 10 penetrates the inside of the box body 1, and the two bag bodies 2 sandwich the steel material 10 inside the box body 1. Two electrodes 3 are provided inside each bag body 2.

  The box 1 is formed by integrating, for example, a cylinder 1A that surrounds a part of the steel material 10 and an end 1B that is provided at each open end of the cylinder 1A. For example, the cylindrical body 1A has a rectangular cross-sectional shape.

  The steel material 10 is, for example, an overhead wire passing between utility poles, and is formed by bringing together a plurality of steel materials 10a. The steel material 10 is usually exposed to the outside air. For example, due to corrosion, the total cross-sectional area of each steel material 10a, that is, the total area of seven circles indicated by the arrow D in FIG. In the illustrated system, a change in the cross-sectional area D due to this corrosion or the like is detected. For example, at a certain timing (for example, when the steel material 10 is installed), a value (a resistance value described later) corresponding to the cross-sectional area D is measured, the resistance value is measured again after a predetermined period, and the resistance value measured twice. The difference, that is, the difference in the cross-sectional area D is detected. The cross-sectional area D is the cross-sectional area at the position indicated by the arrow D in FIG.

  Each bag body 2 is in an inflated state, and has a bag body portion 2A that is in close contact with the steel material 10 and the cylinder body 1A. The bag body 2 includes rubber (natural rubber), silicon rubber, and the like. For example, the bag 2 is inflated by containing a liquid such as saline, a viscous liquid, or a gas such as neon gas.

  FIG. 1 shows an example of a configuration for keeping the bag body 2 in an inflated state.

  For example, a saline solution is placed in the container 4, and the bag body 2 expands when the pump 5 causes the saline solution in the container 4 to flow into the bag body 2. When the internal pressure of the bag body 2 exceeds a certain level, the check valve 6 is opened by the internal pressure, and saline passes through the check valve 6 and is collected in the container 4. That is, if the saline solution circulates, the internal pressure of the bag body 2 is maintained above a certain level.

  Each bag 2 swells by such a mechanism, and is in close contact with the steel material 10 and the cylinder 1A. Therefore, when the cross-sectional area D changes, the area of the portion indicated by the arrow E in FIG. 1, that is, the cross-sectional area of the bag portion 2A (hereinafter referred to as cross-sectional area E) changes. The cross-sectional area E is a cross-sectional area at a position indicated by an arrow e in FIG.

  The electrode 3 is provided at each point in order to measure the resistance value between the two points across the cross section e. That is, the two electrodes 3 are arranged to sandwich the cross section e. The electrode 3 penetrates the bag body 2, and a part of the electrode 3 is exposed to the outside of the bag body 2. A portion of the bag 2 through which the electrode 3 penetrates is sealed (shielded) so that the liquid inside does not leak. The electrode 3 is electrically connected to the electric wire 3 a (conductor) outside the bag body 2. The electric wire 3a is connected to the resistance measuring device 7, and the resistance measuring device 7 passes a current through the electric wire 3a and measures the resistance value based on the current value.

  In addition, it is the part in the bag body 2 of the electrode 3 that has fulfilled the original function of the electrode 3, and the part outside the bag body 2 considers the convenience of connection with the electric wire 3a etc. It is only integrated with the inner part. Therefore, the portion outside the bag body 2 is a conductor electrically connected to the portion inside the bag body 2, and the electric wire 3a (conductor) is electrically connected to the conductor. I can say that.

  The resistance value is inversely proportional to the cross-sectional area E. Therefore, if the resistance value measured by the electrode 3 of one bag body 2 is increased by, for example, 0.1% with respect to the previous measurement, the cross-sectional area E of the bag body 2 is decreased by 0.1%.

  Further, if the resistance value measured by the electrode 3 of the other bag body 2 is increased by 0.1% compared to the previous time, the cross-sectional area E of the bag body 2 is also decreased by 0.1%.

  The total area of the 0.1% reduction of the one bag 2 and the 0.1% reduction of the other bag 2 is equal to the area of the increase in the cross-sectional area D. That is, it can be said that the cross-sectional area D is increased by the same area as the total area. A decrease in the cross-sectional area D can be detected by the reverse logic. That is, a change in the cross-sectional area D of the steel material 10 can be detected using the cross-sectional area change detecting device of the present embodiment.

  Further, if the initial cross-sectional area D is known, the current cross-sectional area D can be calculated from the cross-sectional area D and the increase or decrease (change amount).

  Further, the resistance value is proportional to the resistivity of the substance (such as saline) in the bag body 2. On the other hand, a resistance value measurement range is defined for the resistance measuring instrument 7, and the accuracy is high in that range. Therefore, the detection accuracy of the change in the cross-sectional area D can be increased by setting the resistivity so that the resistance value enters the measurement range.

  Assuming that the resistance value measured by the electrode 3 of one bag body 2 and the resistance value measured by the electrode 3 of the other bag body 2 are the same, the resistance value measurement is performed in either bag body 2. Can be omitted. That is, the electrode 3 etc. in the bag body 2 are unnecessary.

  An internal pressure detector 8 that detects internal pressure is provided inside the bag body 2. The internal pressure detector 8 is connected to a display (both not shown) via a lead wire, and the display displays the internal pressure.

  The cross-sectional area D hardly changes in a short time such as one measurement time. Thus, if there is no change in the cross-sectional area D, it is preferable that there is no change in resistance value. For this purpose, it is necessary to make the degree of adhesion of the bag portion 2A to the steel material 10 and the cylindrical body 1A constant.

  However, when the internal pressure of the bag body 2 changes, the degree of adhesion also changes. That is, unless the internal pressure is kept constant, the degree of adhesion is not constant, and the resistance value changes even if the cross-sectional area D is constant. That is, even if the cross-sectional area D is constant, a difference (change) may occur in the resistance value at each time.

  Since the internal pressure detector 8 can detect the internal pressure, it is only necessary to keep the detected internal pressure constant in each measurement. In other words, the degree of adhesion should be kept constant. Thereby, if the cross-sectional area D is constant, the resistance value can be made the same. That is, the change in the resistance value correctly reflects the change in the cross-sectional area D, so that the change in the cross-sectional area D can be correctly detected.

(Modification)
In the present embodiment, as shown in the schematic diagram of FIG. 3A, two bags 2 are used for one steel material 10, but as shown in the schematic diagram of FIG. One bag 2 may be used for one steel material 10. Conversely, three or more bags 2 may be used.

  As can be seen in FIG. 3 (b), one bag 2 is bent in a strain (bite), so the degree of adhesion to the steel material 10 and the cylinder 1A is reduced. On the other hand, if two or more bag bodies 2 are used, the bag bodies 2 are not bent (distorted), the degree of adhesion is increased, and the change in the cross-sectional area D can be detected more correctly.

  In addition, in this Embodiment, although the steel material 10 was made into the overhead wire which passes between utility poles, steel materials other than an overhead wire may be sufficient. For example, the steel material may be a vertical column. Further, the steel material may have a hollow structure.

  Moreover, in this Embodiment, although the cross-sectional shape of 1 A of cylinders was made into square, circular, an ellipse, etc. may be sufficient.

  As described above, according to the present embodiment, the swelled bag body 2 having the cylindrical body 1A surrounding the steel material 10, the steel material 10 and the bag body portion 2A closely attached to the cylindrical body 1A, and the steel material. Electrode provided at each point for measuring a resistance value between two points sandwiching the cross section e that changes in accordance with the area (E) of the cross section e of the bag portion 2 that changes due to a change in the cross sectional area D of 10 3 and a conductor (3a) that is provided integrally with or separately from the electrode for each electrode 3 and is electrically connected to the electrode and drawn out of the bag body 2, the change in the resistance value is the steel material 10. Therefore, the change in the cross-sectional area D of the steel material 10 can be accurately detected.

DESCRIPTION OF SYMBOLS 1 Box 1a Cylindrical body 1b End part 2 Bag body 2A Bag body part 3 Electrode 3a Electric wire 4 Container 5 Pump 6 Check valve 7 Resistance measuring device 8 Internal pressure detector 10, 10a Steel material D Cross-sectional area E of steel material 10 Bag body part Cross section e of cross section e of 2A Cross section of bag portion 2A

Claims (3)

A cylinder surrounding the steel,
A bag body in an inflated state having a bag body portion in close contact with the steel material and the cylinder;
Provided at each point to measure a resistance value between two points sandwiching the cross section in the bag portion that changes according to the cross-sectional area of the bag portion that changes due to a change in the cross-sectional area of the steel material. Electrodes,
An apparatus for detecting a change in cross-sectional area, comprising: a conductor provided integrally or separately with the electrode for each electrode, and electrically connected to the electrode and drawn out of the bag. Comprising two or more of the bags,
The cross-sectional area change detection device according to claim 1, wherein each of the bags includes the two electrodes and the two conductors. When there is no change in the cross-sectional area of the steel material, an internal pressure detector that detects an internal pressure of the bag body that affects the degree of adhesion of the bag body portion to be constant when the resistance value is constant is provided. The cross-sectional area change detecting device according to claim 1.

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