JPS62133628A - Overheat detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an overheat detector that detects an abnormal temperature rise in a high voltage conductor.

[Conventional technology]

It can deteriorate the conductors of high-voltage, large-current circuits and cause the temperature of the conductors to rise abnormally, leading to a major accident. In order to prevent such accidents, it is necessary to control temperature changes in the high voltage conductors. Since the target is a high-voltage conductor, it is difficult to directly detect its temperature. Conventionally, temperature was detected by pasting temperature-indicating paper at the necessary points, but this circuit makes it difficult to visually check the temperature detection points. There was a problem where it could not be used.

Therefore, an overheat detection device as shown in FIG. 3 has been proposed. This overheat detection device includes a heat conductive member 20 fixed to the high voltage conductor, an optical fiber λ21 fixed to the heat conductive member 20 with a part curved, and an optical signal applied to one end of the optical fiber 21. The main body 22 detects the level of the optical signal output from the section and outputs an alarm signal when the level falls below a predetermined level.

As shown in FIG. 4, the heat conducting member 20 has a shape in which a cut portion 20a is provided in a part thereof, and is attached in a U-shape when the temperature of the high voltage conductor reaches a predetermined temperature. The optical fiber 21 thermally shrinks and bites into the edge portion 20a, thereby destroying the cladding and cladding layers of the optical fiber X21.

When the cladding layer of the optical fiber 21 is destroyed, the main body 22
Since the received optical signal level is below the predetermined level, 'Yf
[Outputs 3 signals.

[Problem that the invention seeks to solve]

In Nio's conventional example, overpayment detection of a detected object such as a high voltage conductor relies on the thermal shrinkage characteristics of the optical fiber 21, and there is a problem in that the alarm output temperature cannot be set freely. In the conventional configuration, the alarm output temperature is limited to 40° Cc', and it is extremely difficult to set the alarm output temperature below this limit. However, in power equipment, 105°
C or more is considered overheating, so if the high voltage conductor is heated to 105°
When the value exceeds C, it is desirable that an x-sum signal is output.

An object of the present invention is to provide an overheat detector that can freely set the temperature at which it is determined that the temperature is over.

[Means for solving problems]

The overpayment detector of the present invention includes a heat conducting member and a heat conducting portion 1A.
An optical fiber was attached to the optical fiber, and a shape 10 alloy piece was attached to the 445 member so as to deform at a predetermined operating temperature and destroy the cladding layer of the optical fiber.

[Effect]

According to the configuration of the present invention, the shape memory alloy flake attached to the heat conducting member deforms and destroys the cladding layer of the optical fiber when it reaches a predetermined operating temperature. By setting, the temperature at which J2A is determined can be freely set.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 and 2. FIG. 1 is a perspective view showing the structure of one embodiment,
FIG. 2 is an enlarged plan view showing the structure of the main part.

The overheat detector of this embodiment includes a heat conductive member 1, an optical fiber 2 attached to the heat conductive member 1, and a structure in which the heat conductive member 1 is deformed at a predetermined operating temperature to destroy the cladding layer of the optical fiber 2. The shape memory alloy piece 3 attached thereto is provided.

On the upper surface of the heat conducting member 1, there is a U-shaped optical fiber mounting groove 1a for mounting the optical fiber 2, and a shape memory alloy piece 3 connecting the straight parts of the mounting groove 1a when the shape memory alloy piece 3 is below the operating temperature. Shape memory alloy piece mounting groove 1b and relief/nlc that allow shape memory alloy piece 3 to deform when the temperature rises above the operating temperature.

1d is formed.

A part of the optical fiber 2 is installed in the optical fiber installation groove 1a, and the optical fiber 2 is installed in the optical fiber installation groove 1a. It is adhered to a part of the heat conducting member 1 so as not to come off from R1a. When the cladding layer is destroyed by the shape memory alloy piece 3, the optical signal transmitted by the optical fiber 2 is greatly attenuated.

The shape memory alloy piece 3 has edge portions 3a at both ends.

3b, and below the operating temperature it takes on a bent shape as shown by the solid line in FIG. 2, and above the operating temperature it takes on a straight shape at the second recess as shown by the two-dot chain line. The operating temperature of the shape memory alloy piece 3 is set to a temperature at which it is determined whether the detected member to which the heat sensitive member 1 is fixed is overheated.

In this embodiment, by fixing the heat conducting member 1 to the object to be detected such as a high voltage conductor and constantly applying an optical signal to one end of the optical fiber 2, the object to be detected is heated to a temperature higher than that at which it is determined that the object is overheated. In this case, the shape memory alloy piece 3 is deformed, and its edge portions 3a and 3b bite into the cladding layer of the optical fiber 2 and break it, so that the level of the optical signal output from the other end of the optical fiber 2 decreases. Therefore, by detecting the output level of this optical signal, it is possible to determine whether the object to be detected is overheated.

By using this embodiment, it becomes possible to detect overheating of 105° C., which is considered to be an overheating point in power equipment, which was difficult in the conventional example.

In this embodiment, since the operating temperature of the shape memory alloy piece 3 can be set appropriately, the overheat detection range of the object to be detected is greatly increased.

In the above-described embodiment, the edge portions 3a and 3b are formed at both ends of the shape memory alloy piece 3, but in this invention, an integral part of the shape memory alloy piece 3 is fixed to a heat-sensitive member, and the other end portions are fixed to the heat-sensitive member. Edge portions may be formed only on the edges. Further, in the present invention, a plurality of shape memory alloy pieces 3 may be attached to the heat conducting member 1 in order to further ensure destruction of the cladding layer of the optical fiber 2.

〔Effect of the invention〕

According to the overheat detector of the present invention, the shape memory alloy piece is attached to the heat conducting member so that it deforms and destroys the cladding layer of the optical fiber when a predetermined operating temperature is reached, so the operating temperature of the shape memory alloy piece can be set appropriately. The temperature at which overheating of the detected object is determined can be freely set.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the structure of one embodiment of the present invention;
FIG. 3 is a plan view showing a main part of an embodiment of the present invention, FIG. 3 is a view showing the configuration of an overheat detection device, and FIG. 4 is a perspective view showing the structure of a conventional example. 1... Heat conducting member, 2... Optical fiber, 3... Shape memory alloy piece" Figure 3 Figure 4

Claims (1)

[Claims] An overheat detector comprising a heat conducting member, an optical fiber attached to the heat conducting member, and a shape memory alloy piece attached to the heat conducting member so as to deform at a predetermined operating temperature and destroy a cladding layer of the optical fiber. .