JPH0727632A - Overheat indication device - Google Patents

Abstract

PURPOSE:To make it possible to detect the abnormal overheat of an object by opening a metal member at the bottom surface of a case by a shape memory effect when an object reaches a specified temperature, dropping an overheat preventing plate from a case, and visually recognizing the suspended display plate. CONSTITUTION:A case 4, wherein the bottom surface is formed out of a metal member 2 having the shape memory effect and the cross section has a U-shape, is attached to a connecting part 1 with compressing terminal by using an attaching band 5. In the case 4, an overheat indication plate 3, where, e.g. fluorescent paint is applied on both surfaces, is connected to a heat resistant string 6. One end of the string is fixed to the upper part of the case 4. When the temperature of the connecting part 1 rises up and the abnormal overheat state occurs, the temperature of the member 2 rises due to heat conduction and thermal radiation through the case 4. When the temperature becomes a shape memory effect temperature or higher, the part, which is bent by 90 degrees, becomes straight, and the bottom surface of the case 4 is opened. Therefore, the contained display plate 3 is dropped and suspended with the string 6. Thus, the plate can be visually recognized readily from the remote place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric wires, bare conductors, connection parts in electric circuits such as bus ducts, and the like.
The present invention relates to an overheat display device that detects abnormal overheat and displays it on a display plate.

[0002]

2. Description of the Related Art At a connecting portion where an electric wire, a bare conductor or the like is electrically connected using a compression terminal, contact resistance increases due to poor compression connection of the compression terminal, and Joule heat is generated in this portion. It may be generated and become high temperature. Needless to say, the heat generated by the Joule heat is harmful to the electrical continuity between the conductors, and it has also been a cause of a power failure accident or a fire.

With respect to the generation of harmful heat in the past, in order to detect the generated heat quickly and prevent a burnout or a power failure accident, the color changes when a certain temperature is reached, and this color change informs the observer of abnormal heat generation. There is one using a temperature indicating material. This temperature indicating material has been widely used since it can be applied to a connecting portion or the like by a simple means such as applying as a paint or attaching as a label.

[0004]

However, since this thermosensitive material is discolored by a thermochemical reaction, it does not discolor even if it reaches a predetermined temperature during use, or conversely reaches a predetermined temperature. Even without it, the temperature-dependent deterioration of color change was unavoidable. Especially when used outdoors, UV rays,
There was a problem that performance was deteriorated in a short period of time due to other environmental conditions, the original purpose could not be achieved, and mischief was a concern. Also, repaint the paint,
It required re-labeling and other work, which was also extremely troublesome.

As another method, a method of performing remote measurement by attaching a temperature sensor or the like to a connection portion to be monitored can be considered, but this requires a large device, enormous cost, and a transmission / reception system. Maintenance was difficult.

The present invention has been made in view of the above-mentioned circumstances, and can be easily attached to a connecting portion or the like, and the appearance thereof informs an observer of abnormal overheating at a glance, and thus the above-mentioned conventional method is used. It is an object of the present invention to provide a new overheat display device which solves the problems.

[0007]

SUMMARY OF THE INVENTION The present invention hangs an overheat indicator board with a heat resistant cord inside a case having a metal member having a shape memory effect attached to the surface of an object whose overheat is to be detected on the bottom surface. Connect so that it lowers and store it,
When the object reaches a predetermined temperature, the metal member on the bottom of the case is opened based on the shape memory effect, the overheat display plate is dropped from the case, and the hanging overheat display plate is visually confirmed to overheat the object. It is an overheat display device which detects temperature.

[0008]

When a predetermined temperature is reached, the bottom surface of the case is surely opened based on the shape memory effect, and the display plate is visually recognized to detect abnormal overheating of the object.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a state of a connecting portion before abnormal overheating, and FIG. 2 is a sectional view taken along the line AA ′ of FIG. That is, for example, a case 4 having a U-shaped cross section whose bottom surface is the metal member 2 having a shape memory effect is attached to the connection portion 1 by the compression terminal for monitoring abnormal overheating with the attachment band 5. In the case 4, a heat-resistant string 6 is connected to an overheat display plate 5 formed on both sides by applying, for example, fluorescent paint.
One end of the housing accommodates what is fixed to the upper part of the case 4.

The shape memory alloy metal member 2 on the bottom surface of the case 4 is, for example, a Ti--Ni alloy, an Au--Cd alloy, or C.
It is made of a u-Zn-Al alloy, and the transformation temperature can be set to various values by changing the alloy composition. In this case, the shape is memorized so that the metal member 2 formed by bending at 90 degrees straightly deforms at a predetermined temperature.

Now, assuming that the temperature of the connecting portion 1 rises and is in an abnormally overheated state, the metal member 2 is heated by heat conduction and heat radiation through the case 4, and reaches a temperature above the shape memory. Then, the metal member 2 becomes straight as shown in the front view of FIG. 3 and the BB ′ arrow view of FIG. 4,
The bottom surface of the case 4 is open. Therefore, the overheat display plate 3 housed in the case 4 falls and is suspended by the string 6, which can be easily viewed from a distance.

In general, an object whose abnormal heat is desired to be detected is often placed at a high place, and monitoring is usually performed by looking from the lower side. Therefore, it is possible to easily detect that the connecting portion 1 is abnormally overheated by the suspended overheat display plate 3. In addition, at the connection portion of the electric wire used in the railway, if it is necessary to inspect at night, it is effective to form the overheat display board 3 by applying the night paint which emits light from the flashlight on both sides. .

[0013]

As described above, in the overheat display device of the present invention, the metal member on the bottom surface of the case is formed of a shape memory alloy that returns to its original shape when heated to a constant temperature for the detection of overheat. Even when used, the temperature indication does not change, and abnormal overheating can be displayed extremely accurately, and high reliability can be obtained. In addition, the display board has a simple structure that only hangs from the case, and it is possible to confirm the presence or absence of abnormal overheating even at a distance, and it is not necessary to make fine adjustments to the metal members described above, and mass production is possible. As a result, it is inexpensive, can be used repeatedly, and is an excellent overheat display device with no failure.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which an overheat display device according to an embodiment of the present invention is attached to a connecting portion,

FIG. 2 is a view taken along the line AA ′ of FIG.

FIG. 3 is a front view of the overheat display device in a state where the connection portion is overheated abnormally;

FIG. 4 is a view taken along the line BB ′ of FIG.

[Explanation of symbols]

 1 Connection part by compression terminal 2 Metal member having shape memory effect 3 Overheat display plate 4 Case 5 Mounting band 6 Heat resistant string

Claims (1)

[Claims] 1. An overheat display plate is connected and stored in a case having a metal member having a shape memory effect, which is attached to the surface of an object whose overheat is to be detected, on the bottom surface thereof so as to hang the overheat display plate with a heat resistant string. When the object reaches a predetermined temperature, the metal member on the bottom surface of the case is opened based on the shape memory effect, the overheat display plate is dropped from the case, and the hanging overheat display plate is visually confirmed. An overheat display device characterized in that the overheat temperature of an object is detected.