JPH07100419B2 - Abnormal heat detection device for feeder connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an abnormal heat generation detection device for a feeder connection that detects abnormal heat generation at a feeder connection.

B. SUMMARY OF THE INVENTION The present invention is a device for detecting abnormal heat generation in a feeder connection that detects abnormal heat generation in a feeder connection. By providing a heat sensor made of a shape memory alloy that detects abnormal heat generation, the abnormal heat generation at the connection part of the feeder is instantly visible.

C. Prior Art As shown in FIGS. 3 (a) and 3 (b), generally, the straight line connection of the feeder line in the electric railway line is made by connecting the feeder line 1 made of hard copper strands or hard aluminum strands. After inserting from both ends of the pipe 2, the linear connecting pipe 2 is compressed and deformed by using an electric wire connecting hydraulic machine (rated compression force 100t) not shown.

By the way, when connecting the feeder wire as described above, if there is an error as described below, the connecting part will generate abnormal heat immediately after the connection and become even hotter over time. Since it is difficult to identify, there is a risk of causing a fire wire breakage accident of the feeder cable.

Therefore, conventionally, a thermo label that changes color at 60 ° C is attached to an appropriate place on the outer surface of the straight connecting tube 2, or a thermo paint is applied, or the surface of the straight connecting tube 2 is fixed by a non-contact infrared radiation thermometer. I was trying to measure the temperature.

Here, the error in connecting the electric wire is (a) an old wire having a large amount of oxide film attached to the surface of a hard copper stranded wire or a hard aluminum stranded wire to be connected, and the film is not sufficiently removed at the time of connection. When (b) a hard copper stranded wire and a hard aluminum stranded wire are connected, (c) a straight connecting pipe with an inner diameter larger than the outer diameter of the feeder wire is mistakenly used,
And (d) the case where a compression die that does not fit the outer diameter of the straight connecting pipe is attached to the hydraulic machine for compression.

Since the connection work is often performed at midnight, the above-mentioned mistakes are more likely to occur. By the way, if the above error occurs, and if the connection is due to compressive deformation, the electrical contact between the inner surface of the straight connecting pipe and the outer surface of the wire becomes incomplete, causing abnormal heat generation. Continuing that state promotes air oxidation due to heating, further deteriorating electrical contact, causing further heat generation, and the heat effect also promotes a decrease in material strength due to coarsening of the crystal grains of the metal structure of the feeder wire, resulting in disconnection. An accident will occur.

D. Problems to be Solved by the Invention The above conventional example has the following drawbacks. In other words, thermo labels and thermo paints have no weather resistance, and dust in the atmosphere adheres to them, making it difficult to determine discoloration. Especially, since the straight line connection is located at a height of 10 meters above the ground, Its determination from is more difficult.

On the other hand, even in the infrared radiation thermometer, it is difficult to detect abnormal heat generation of the straight connecting pipe at an early stage unless heat is generated at a considerably high temperature because the measurement target is small and the distance between them is more than ten meters. is there.

Moreover, since the infrared radiation thermometer is a very expensive and heavy precision measuring instrument, it is unsuitable as a device that is simply used at the site where it is to be measured.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an abnormal heat generation detection device for a feeder connection, in which abnormal heat generation at the feeder connection can be instantly visually recognized.

E. Means for Solving Problems The present invention is directed to a connecting pipe into which feeder wires to be connected to each other are inserted or an outer peripheral surface of the feeder wire in the vicinity of the connecting pipe, from a shape memory alloy for detecting abnormal heat generation of a connecting portion. A plurality of plate-shaped heat sensors are provided, and the entire one surface of the heat sensor is brought into direct contact with the outer peripheral surface of the connecting pipe or the like.

F. Action The present invention utilizes the property of the shape memory alloy that returns to its shape at a predetermined set temperature, and when the connection portion of the feeder is abnormally heated, the temperatures of the connecting pipe and the feeder rise, and these When the temperature reaches a predetermined temperature, the heat sensor returns to its shape and is deformed, so that abnormal heat generation of the connection portion can be instantly recognized by visual observation.

G. Examples Examples of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a feeder wire, 2 is a straight connecting pipe, and the figure shows the state after compression deformation. Before the compression deformation, the straight connecting pipe 2 has a circular cross-sectional outer shape and is tapered at both ends, but is deformed into a hexagonal cross-sectional outer shape except for a part of both ends by compression. The portion 3 which is not subjected to the compressive deformation is formed at six locations at equal intervals in the circumferential direction, and plate-shaped heat sensor elements 4a, 4b, 4c, 4d, 4e, 4f are arranged at the respective locations.
The base of each heat sensor element is fixed by a fastening ring 5.

The thermal sensor elements 4a, 4b, 4c, 4d, 4e, 4f are made of a shape memory alloy that recovers its shape along with the transformation of the deformed twin martensite into the matrix austenite by the thermoelastic martensite transformation at a constant temperature. In this case, the shape memory alloy is preferably a NiTi-based shape memory alloy having a martensite phase at room temperature and Ms and As points suitable for causing transformation into a matrix phase at 100 ° C.

In the figure, 6 is a fluorescent dye-containing thermoplastic sheet adhered to each of the thermal sensor elements 4a, 4b, 4c, 4d, 4e, 4f in order to make it easy to monitor the shape recovery of the shape memory alloy from a distance. Bayer LISA KL 1-9400 (polycarbonate) is preferred. The sheet 6 having such a good light-converging property emits intense fluorescence and shines even in the moonlight at night or the light of a flashlight from a distance of a dozen meters, so that the shape change can be easily confirmed. The emission color of the sheet 6 is set to orange / purple or colorless, avoiding red, green, and blue because the detection device is used for the linear connection portion of the feeder in the train track.

The reason why the transformation temperature of the memory alloy into the parent phase is limited to 100 ° C is that the temperature of 100 ° C is higher than the maximum temperature of the linear connection part in summer, and abnormal heat generation is detected as early as possible at the lowest possible temperature. This is because the requirement to do so is met.

In order to mount such a detecting device on the straight connecting pipe 2, the fastening ring 5 having a characteristic that the transformation temperature to the parent phase is around 0 ° C.
Is expanded at a low temperature of 0 ° C. or lower to insert both ends of the straight connecting pipe 2 into the fastening ring 5, and then the thermal sensor elements 4a, 4b, 4c, 4d, 4e are provided between the fastening ring 5 and the straight connecting pipe 2. , 4f are inserted, and then the fastening ring 5 is returned to its shape at room temperature to fix the thermal sensor element. Thermal sensor elements 4a, 4b, 4
C, 4d, 4e and 4f are brought into close contact with the surface of the straight connecting pipe 2 by deformation at room temperature.

Next, the operation of the detection device will be described. Thermal sensor elements 4a, 4b, 4c, 4d, 4e, 4f when there is no abnormality in the straight line connection
Is in close contact with the straight connecting pipe 2, but when abnormal heating occurs and the temperature of the straight connecting pipe 2 reaches 100 ° C., the thermal sensor element is linear as shown by the chain double-dashed line due to the shape recovery accompanying the transformation to the mother phase. It rises away from the surface of the connecting pipe 2. That is, the memory shape in the matrix of the shape memory alloy is the shape indicated by the chain double-dashed line. Then, such shape restoration can be easily confirmed by monitoring the fluorescence emission of the sheet 6.

FIG. 2 shows another embodiment of the present invention. In FIG. 2, the same reference numerals as in FIG. 1 indicate the same or corresponding parts. This figure shows the state after the straight connecting pipe 2 is compressed and deformed. In the portion where the straight connecting pipe 2 has a hexagonal cross section, a plurality of grooves 7 are formed in two rows at equal intervals in the circumferential direction.
Plate-shaped heat sensor elements 4a, 4b, 4c, 4d, 4e, 4f are arranged in each groove 7, and a sheet 6 is provided on the outer surface of each heat sensor element.
Are glued together.

The heat sensor element is fixed as follows. That is,
The base of the thermal sensor element is inserted into the groove 7 and the base of the thermal sensor element is fixed by the inlay during the compression deformation of the straight connecting tube 2.

The portions of the thermal sensor elements 4a, 4b, 4c, 4d, 4e, 4f projecting from the groove 7 are bent at a right angle and brought into close contact with the surface of the straight connecting pipe 2.

In this embodiment, the thermal sensor elements 4a, 4b, 4c, 4d, 4e, 4f remain in close contact with the straight connecting pipe 2 if there is no abnormality in the straight connecting pipe. The thermal sensor element returns to its original shape and stands upright as shown by the chain double-dashed line.

H. Effect of the Invention As described above, since the present invention utilizes the shape recovery of the shape memory alloy, it is possible to instantly visually recognize the abnormality of the linear connection portion.

Further, since the shape memory alloy is used, the weather resistance is excellent, and the performance does not deteriorate even when exposed to the outdoors for a long time.

[Brief description of drawings]

1 (a) is a plan view of an abnormal heat generation detecting device for a feeder connection according to the present invention, FIG. 1 (b) is a side view of FIG. 1 (a), and FIG. 2 is another view of the present invention. FIG. 2 (a) is a plan view, FIG. 2 (b) is a side view of FIG. 2 (a), and FIG. 3 is a conventional linear connecting portion. FIG. 3A is a plan view and FIG. 3B is a side view. 1 ... feeder, 2 ... connecting pipe, 4a, 4b, 4c, 4d, 4e, 4f ... thermal sensor element.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fuki Haba 2-1-1 Osaki, Osaki, Shinagawa-ku, Tokyo Stock company company Meidensha (72) Inventor Kunio Yonahara 3-7-7 Nishigotanda, Shinagawa-ku, Tokyo Union In Kasei (56) Bibliography Sho 60-60873 (JP, U) Sho 59-116867 (JP, U)

Claims (1)

[Claims] 1. A plurality of plate-shaped thermal sensors made of a shape memory alloy for detecting abnormal heat generation of a connecting portion are provided on an outer peripheral surface of a connecting pipe into which feeder wires to be connected to each other are inserted or in the vicinity of the connecting pipe. An abnormal heat generation detecting device for a feeder connection, characterized in that the entire one surface of the heat sensor is brought into direct contact with the outer peripheral surface of a connecting pipe or the like.