JPH0429389Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an overheat detector that detects abnormal temperature rises in high voltage conductors.

BACKGROUND TECHNOLOGY Conductors in high-voltage, large-current circuits deteriorate and the temperature of the conductors rises abnormally, which can lead to serious accidents.
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 detector as shown in FIG. 3 was proposed and is currently in use. This overheating detector is
A heat conducting member 10 having an edge portion A, and an edge portion A
The optical fiber 11 has both ends of a curved portion B sheathed on the heat conducting member 10 fixed to the heat conducting member 10. When the temperature of the heat conducting member 10 rises and the thermal contraction of the optical fiber 11 increases, the edge portion A destroys the cladding layer of the optical fiber 11. The heat conducting member 10 is brought into contact with the above-mentioned high voltage conductor, light is applied from the light emitting device 12 to the optical fiber 11, and the light output is detected by the light receiving device 13. When the temperature of the high voltage conductor becomes abnormally high, the cladding layer of the optical fiber 11 is destroyed and the optical output is reduced as described above.
Detect with.

Problems to be Solved by the Invention In the conventional overheat detector as described above, there is only one breaking point in the cladding layer, and if the breaking point is incomplete, the optical output of the optical fiber 11 will be insufficient to reach the discrimination level. overheating of the detected object, such as a high voltage conductor, may not be detected. For this reason, the conventional overheat detector has a problem of low reliability in overheat detection ability.

The purpose of this invention is to provide an overheat detector that can improve the reliability of overheat detection ability.

Means to solve the problem The overheat detector of this invention has an edge portion and comprises a heat conductive member attached to the conductor to be detected, and an optical fiber having a curved portion that covers the edge portion and both ends of which are fixed to the heat conductive member, the edge portion and the curved portion being provided in multiple locations, and the optical fiber being made of a heat shrinkable material.

Effects According to the configuration of this invention, by providing multiple edge portions and curved portions, the number of fracture points in the cladding layer of the optical fiber increases, and the drop in optical output during overheating detection can be increased. Overheat detection operation can be performed reliably.

Embodiment FIG. 1 is a plan view showing the configuration of an embodiment of this invention. This overheat detector is directly attached to a conductor (not shown) that is the object to be detected, and
A heat conducting member 1 having an edge portion 1a, and both ends 2b, 2 of a curved portion 2a that is attached to the edge portion 1a.
c is provided with an optical fiber 2 fixed to the heat conducting member 1, the edge portion 1a consists of a corner of a square column 1b, and the curved portion 2a consists of a spiral portion wound around the square column. The optical fiber 2 is made of heat-shrinkable material such as PMMA (polymethyl methacrylate).
Plastic fiber is used.

The heat conducting member 1 includes a curved portion 2a of the optical fiber 2.
narrow grooves 1c, 1d formed in order to fit both ends 2b, 2c and arranged in parallel, and narrow grooves 1c, 1d.
a circular groove 1e whose side wall is formed in a circular shape so that the optical fiber 2 can be wound around the square pillar 1b;
A mounting hole 1f formed in the center of the square column 1b is provided.

The optical fiber 2 has both ends 2b and 2c of the curved portion 2a near the opening ends of the narrow grooves 1c and 1d pressed together with a cover member (not shown) and an adhesive AD.
The curved portion 2a is extensibly wound around the square pillar 1b in a spiral shape. Therefore, when the temperature of the heat conducting member 1 rises, the curved portion 2a of the optical fiber 2 bends into four edge portions 1 due to thermal contraction.
a, and the cladding layer of the optical fiber 2 is finally destroyed. One end of this optical fiber 2 is connected to a light emitting device 3, and the other end is connected to a light receiving device 4.

The light output from the light emitting device 3 is transmitted through the optical fiber 2.
The light passes through the curved portion 2a from one end to the other end and is received by the light receiving device 4. In this overheat detector, when the heat conductive member 1 is overheated, the optical fiber 2 is thermally contracted, and the cladding layer of the optical fiber 2 is broken at the edge portions 1a provided at four locations. Since the optical output of the device is greatly reduced, the overheat detection operation can be ensured even though the structure is simple.

Next, another embodiment of this invention will be explained based on FIG. 2. In this overheat detector, unlike the above-described embodiment, the edge portions 1a formed in the meandering groove 1g of the heat conducting member 1 are arranged in three zigzag positions, and the optical fiber 2 is attached to the meandering groove 1g to form a curved portion 2a. are formed in a meandering arrangement at three locations. Also in this embodiment, there are three cladding layer break points of the optical fiber 2, and the optical output of the optical fiber 2 is greatly reduced, so that the reliability of the overheat detection ability is improved.

Effects of the invention According to the overheat detector of this invention, the number of breaking points of the cladding layer of the optical fiber increases, and the drop in optical output during overheat detection can be increased, so the overheat detection operation is performed reliably and is simple. Despite the structure, the reliability of overheat detection ability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of one embodiment of this invention, FIG. 2 is a perspective view showing the structure of another embodiment of this invention, and FIG. 3 is a perspective view showing the structure of a conventional example. 1... Heat conducting member, 1a... Edge portion, 1b...
Polygonal prism, 2... optical fiber, 2a... curved part,
2b, 2c...Both ends.

Claims (1)

[Claims for Utility Model Registration] (1) A heat conducting member having an edge portion and attached to a conductor to be detected, and a light beam having both ends of a curved portion circumscribing the edge portion fixed to the heat conducting member. What is claimed is: 1. An overheat detector comprising a fiber, wherein the edge portion and the curved portion are provided at a plurality of locations, and the optical fiber is made of a heat-shrinkable material. (2) The overheating detector according to claim (1), wherein the edge portion is a corner of a polygonal prism, and the curved portion is a spiral portion wound around the polygonal prism. (3) The utility model claimed in claim (1), wherein the edge portions are arranged in a zigzag pattern, and the curved portion is formed in a meandering arrangement along each of the edge portions. Overheat detector.