JP2832967B2 - Heat detection device at the junction of electrical conductors - Google Patents

Description

The present invention relates to a device for detecting heat generation at a connection portion of an electric conductor, which detects abnormal heat generation at a connection portion of an electric conductor, for example, a linear connection portion or a branch portion.

B. Summary of the Invention The present invention relates to a heat generation detecting device for detecting heat generation at a connection portion of an electric conductor, comprising: a heat sensor body made of a shape memory alloy that returns to a shape due to a heat load generated at the connection portion of the electric conductor; The connection part with the tie wrap that attaches the sensor body to the connection part of the electric conductor,
By wrapping and fixing with a fixed body made of copper tape and fixing it, it is possible to provide a low-cost, highly reliable heat generation detection device that visually detects abnormal heat generation at the connection part of the electric conductor. is there.

C. Prior Art In general, a connection part of an electric conductor, for example, a connection part of a feeder line (a straight connection part, a branch connection part, etc.) in a train line of an electric railway is a fifth connection part, taking a straight connection part as an example. As shown in FIG. 6 and FIG. 6, after inserting the feeder wire 1 made of hard copper stranded wire or hard aluminum stranded wire from both ends of the straight connection pipe 2, using a wire connection hydraulic machine (not shown), The straight connection pipe 2 is configured to be connected by being compressed and deformed.

However, in the connection portion of the electric wire 1 thus configured, a connection failure occurs in the following cases. (A) a hard copper stranded wire or a hard aluminum stranded wire to be connected is an old wire having a large amount of an oxide film adhered to the surface thereof, and the film is not sufficiently removed at the time of connection; When the stranded wire and the hard aluminum stranded wire are connected, (c) When the straight connecting tube 2 having a larger inner diameter than the specified outer diameter of the feeder wire 1 is used by mistake, (d) When the straight connecting tube 2 is This is the case where a compression die that does not fit the outer diameter is attached to a hydraulic machine and compressed.

In addition, since the connection work is often performed at midnight, the above-mentioned error is more likely to occur.

When the above connection failure occurs, especially when the connection is caused by compression deformation, the electrical contact between the inner surface of the straight connection pipe 2 and the outer surface of the electric wire 1 becomes incomplete and causes abnormal heat generation. And the continuation of the state promotes air oxidation by heating, further deteriorating electrical contact,
Heat generation is further caused, and the influence of heat also promotes a decrease in material strength due to coarsening of crystal grains of the metal structure of the feeder wire 1, which may cause a disconnection accident.

In addition, in the case of this connection failure, the connection portion generates abnormal heat immediately after the connection, and becomes higher and hotter with the lapse of time. There is a risk of causing an accident.

For this reason, in order to prevent an accidental disconnection of the heat of the feeder wire 1 due to the poor connection, a thermo label discoloring at, for example, 60 ° C. is applied to an appropriate portion on the outer surface of the straight connection pipe 2 or a thermo paint is applied. Alternatively, the surface temperature of the direct connection pipe 2 is measured by a non-contact infrared radiation thermometer,
Means have been taken to detect abnormal heat generation and take early action.

D. Problems to be Solved by the Invention However, thermolabels and thermopaints do not have weather resistance and adhere to dust in the air, making it difficult to judge discoloration. Is more difficult to determine from the ground.

On the other hand, even in the infrared radiation thermometer, it is difficult to detect the abnormal heat generation of the connection pipe 2 at an early stage unless the target is small and the distance between the two is more than tens of meters, so that the connection pipe 2 does not generate heat. There was a problem.

Such a problem is a problem that occurs not only in the linear connection portion but also in the branch connection portion. In short, it is a problem that occurs in any portion of the connection portion.

The present invention has been made in view of the above points, and has made it possible to easily find a heat generation state at a connection portion of an electric conductor visually.
It is an object of the present invention to newly provide an inexpensive heat generation detecting device for an electric conductor connection portion, which is more reliable and easy to install, and can be installed at a connection portion of an existing electric conductor.

E. Means for Solving the Problems The present invention provides a heat sensor body made of a shape memory alloy that returns to a shape by the heat generated at the connection portion, and a heat detection device provided at the connection pipe or the electric conductor at the connection portion of the electric conductor. Is connected to a tie wrap, which is attached to the connection part, and a fixed body made of copper tape is wound and attached.

F. Function With the above-described configuration, when abnormal heat generation occurs at the connection portion of the electric conductor on which the heat detection device is installed, the heat sensor body is restored by the shape return accompanying the transformation to the parent phase. Both ends return to the shape and stand up so as to be separated from the surface of the connection pipe portion, and the rising state can be easily confirmed visually to detect the heat generation state.

In addition, there is an effect that the heat sensor body and the tie wrap can be easily and quickly connected.

G. Embodiment Hereinafter, an apparatus for detecting heat generation at a connection portion of an electric conductor according to the present invention will be described with reference to an embodiment shown in FIGS. 1 to 4.

It should be noted that in FIGS.
Parts corresponding to those in FIG. 6 and FIG. 6 are denoted by the same reference numerals, and are provided for convenience of explanation.

FIG. 1 is a front view showing a connection portion of a feeder wire, which is one of the connection portions of an electric conductor, to which the heat generation detecting device of the present embodiment is attached. Reference numeral 1 denotes a feeder wire, and 2 denotes a straight connection pipe.

In this example, detectors 6, 6 having different transformation temperatures are mounted at two locations near the center of the straight connection pipe 2.

This heat generation detecting device 6 is configured as shown in FIG. 2, and includes a stainless tie wrap 7, a sensor fixing body 8, and a long plate or rod-shaped heat sensor body 8.

The stainless tie wrap 7 constituting the fixed body is the same as that generally used, the strap 10 is a simple non-magnetic stainless steel plate, and the buckle part 12 has a small and simple fastening structure. It is provided with a self-locking head 13.

In this example, a stainless steel tie manufactured by Daiwa Tape Co., Ltd.
(MLT2S-CP316 or MLT2H-LP316) was used.

A heat sensor body 9 is attached to a middle part of the stainless steel band 10 via a sensor fixing body 8 at a central part thereof.

As shown in FIGS. 2 to 4, the sensor fixing body 8 is formed by applying an adhesive to one side of a copper foil tape as a general electromagnetic shielding product, and further covering a band-shaped shielding tape covered with a paper tape. It is cut and formed into a square with one side of the tape width.

In this example, this electromagnetically shielded copper tape is manufactured by Taiyo Mesh Co., Ltd. (CHO-FOILCCH-36-101-005).
0) was used.

Next, a procedure for attaching the thermal sensor body 9 to the stainless steel tie wrap 7 using the sensor fixed body 8 will be described.

First, as shown in FIG. 3, a first sensor fixing body 8 is attached to the back surface of a joint portion where the center part of the thermal sensor body 9 and the metal band 10 of the stainless tie wrap 7 are orthogonal to each other, with a paper tape. And stick it on the sticking surface that appears.

Next, an operator makes a cut using scissors along both sides of the heat sensor body 9 to reach both sides of the metal band 10.

Next, the small rectangular pieces formed by the cuts are adhered so as to be wound around the metal band 10, respectively.

Next, as shown in FIG. 4, the second sensor fixing body 8 is attached to the joint portion where the first sensor fixing body 8 is attached.
Affix.

That is, the second sensor fixing body 8 is adhered to the surface of the joint portion with the adhering surface which is obtained by peeling off the paper tape.

Next, the square sensor fixing body 8 is cut along both sides of the metal band 10 to the both sides of the thermal sensor body 9.

Next, the sections formed by the cuts are adhered so as to be wound around the heat sensor body 9 and connected as shown in FIG.

In this manner, the thermal sensor body 9 bonded to the tie wrap 7 has a Ni-Ti strip that returns its shape with the transformation of the deformed twin martensite to the parent austenite by thermoelastic martensitic transformation at a constant temperature. It is a shape memory alloy and formed in an elongated shape.

Since it is known that the temperature of the connecting portion of the feeder wire is about 60 ° C. or less in a normal state in summer, the heat sensor body 9 operates at 70 ° C. or more and has a predetermined temperature. At different temperature intervals (for example, 70 ° C, 90 ° C, 110 ° C)
℃) It is better to prepare them and use them with different operating temperatures in combination.

The shape memory alloy 14 which is an element of the heat sensor body 9 has a shape memory portion 14 whose central portion in the longitudinal direction of the elongated shape is a fixing portion to the stainless steel tie wrap 7, and both sides slightly separated from the fixing portion ( It is preferable to set the two portions 14 (outside) from the viewpoint of easy deformation at the time of shape return. As shown in FIG. 1, when the temperature reaches or exceeds a predetermined temperature, both longitudinal sides of the thermal sensor body 9 are deformed by about 90 ° outward (in a direction away from the connecting portion) from the storage portion 14, and the heat is generated. Sensor body 9
The memory shape is applied so that the entire shape is transformed into a U-shape.

Although not shown, it is preferable to apply a fluorescent paint to the surface of the heat sensor body 9 in order to easily monitor the return of the shape of the shape memory alloy from a distance. Furthermore, if the transformation temperature specification of the detector is clarified by color coding 70 ° C transformation white, 90 ° C yellow, 110 ° C red, etc., the transformation temperature specification can be easily identified. It's convenient and doesn't make a mistake.

Then, the abnormal heat detection configured as described above, or
When using heat sensors with different operating temperatures, the heat generation state is color-coded, for example, 70 ° C for white standing, 90 ° C for yellow, 110 ° C for red. Can be easily detected.

Alternatively, means for changing the standing length depending on the temperature may be provided.

The heat detecting device 6 configured as described above connects the stainless tie wrap 7 with a straight connection pipe or a feeder branch pipe.
Alternatively, it is wound around a predetermined position of the feeder wire 1 in the vicinity thereof, and is fixed and attached by the self-locking head 13 of the buckle portion 12 in a tight state.

Further, the thermal sensor body 9 is set so as to be in close contact with the surface of the straight connection pipe or the feeder branch pipe, or the feeder wire in the vicinity thereof at normal temperature.

The heat detecting device 6 of the present embodiment shown in FIG. 2 has one heat sensor body 9 of one kind of transformation temperature attached to a stainless steel band 10 and two parts near the center on the straight connecting pipe. A plurality of different detecting devices 6 are attached to each stainless steel band 10 at 70 ° C (white mark), 90 ° C.
The heat sensor bodies 9 at 110 ° C. (marked in red) and 110 ° C. (marked in red) may be mounted together at a slight distance. By doing so, installation work can be omitted and the detection device can be made more economical.

Further, as in this example, the heat generation detecting device 6 attached with the stainless tie wrap 7 is used not only during the work of updating the connection of the feeder wire 1 but also after the work of connecting the feeder wire 1 or at the existing connection part of the working connection. 2. It can be easily tightened and mounted on the feeder branch pipe or the feeder 1 in the vicinity thereof.

Next, the operation of the detection device will be described with reference to FIG. 1. First, when there is no abnormality in the connection portion, the heat sensor body 9 made of a shape memory alloy is connected to the straight connection pipe 2, the feeder branch pipe, or the feeder. 1 is tightly attached to the surface of the tie wrap 7 by the tightening force of the stainless tie wrap 7, but generates abnormal heat and the temperature of the straight connection pipe, the feeder branch pipe, or the feeder 1 in the vicinity thereof exceeds a predetermined temperature (for example, about 70 ° C.). Then, the heat sensor bodies 9 having the specifications of the respective transformation temperatures are returned to the shape provided for the transformation to the parent phase, and the heat sensor bodies 9 are turned into the straight connection pipe 2 or the feeder branch pipe as shown by the dotted line, or The heat sensor body 9 rises away from the surface of the feeder wire 1 and the entire shape of the thermal sensor body 9 is deformed into a U-shape. That is, the memory shape in the parent phase of the shape memory alloy is the shape indicated by the dotted line. Such a shape restoration can be easily, instantly and surely visually confirmed by monitoring the light emission of the fluorescent paint applied to the surface of the thermal sensor body 9.

H. Effects of the Invention As described in detail above, according to the heat detection device for the connection portion of the electric conductor of the present invention, the heat detection device is connected to the tie wrap and the heat sensor body by a copper tape. Since the fixed body is wrapped around and attached to it,
The following effects are obtained.

The work of winding and attaching the fixed body and joining the tie wrap and the heat sensor body can be performed by a simple operation without using tools other than scissors, and this fixed body is also attached to copper tape with adhesive. Is applied at a low cost, and the amount of use thereof is small, so that there is an effect that the manufacturing unit price of the heat generation detecting device can be greatly reduced.

The bond strength of this part by the sensor fixing body attached from both sides to fix the joint part of the heat sensor body and the stainless steel tie wrap is during normal handling of the heat detection device, especially until the device is attached to the connection part of the electric conductor During handling, a sufficient strength can be assured without any fear that this joint will peel off or tear and break.

The good heat conductivity of the copper foil stretched and wound on both sides of this joint and the heat sensor body or stainless steel tie wrap,
It has the function of promoting heat transfer from the connection portion of the electric conductor to the heat sensor body, and provides a more sensitive operating effect to the heat generation detecting device. If the tape is applied to the entire surface of the office on the side that comes into contact with the connection portion of the electric conductor of the heat sensor body, the heat transfer effect is further enhanced.

Even if the two shape memory parts slightly separated from the joint part at the center of the heat sensor body are covered by the attachment of the fixed body, it does not affect the deformation function of the heat sensor body based on the shape return at the transformation temperature at all. Has the effect that it can function well.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the abnormal heat detecting device for a connection portion of an electric conductor according to the present invention, FIG. 2 is a front view showing the abnormal heat detecting device in an expanded state, and FIGS. Is a perspective view showing a main part of attachment of the heat sensor body, FIG. 5 is a side view showing a conventional feeder wire connection part, and FIG. 6 is a front view thereof. 1 ... feeding wire, 2 ... straight connection pipe, 6 ... abnormal heat detection device, 8 ... fixed body, 9 ... heat sensor body, 10 ... band,
12 ... Buckle part.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-178465 (JP, A) JP-A-63-180533 (JP, A) JP-A-1-119441 (JP, A) JP-A-2- 181372 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01R 4/00 H01R 4/70 H01R 43/00 B60M 1/12 G01N 25/72 G01R 31/00 G01K 11/00

Claims (1)

(57) [Claims] 1. A heat detection device comprising: a heat sensor body made of a shape memory alloy that returns to an upright bent shape due to a generated heat load; and a tie wrap attached to a connection portion of an electric conductor. An apparatus for detecting heat generation at a connection portion of an electric conductor, wherein the connection portion with the tie wrap is fixed by winding and sticking with a fixed body made of copper tape.