JPH0552672A - Thermal change detector - Google Patents

Abstract

PURPOSE:To dispense with a driving power source, and to detect thermal change stably for a long period of time of life span by retaining an optical cable with a structure body deforming by heat, by deforming the cable through the deformation of the structured body, and by attenuating the transmission of a light signal. CONSTITUTION:A structured body 1 is formed out of a shape memory alloy that will be in a bent condition when the temperature reaches not less than a predetermined level. When the structured body 1 is in a condition before the change in the shape, the luminous intensity of the light signal transmitted from a light signal transmitting device 3 to a light signal receiving device 4 through an optical cable 2, is defined as '1'. When a heat 6 is added until the structure 1 regenerates the memory, the cable 2 is bent at a larger degree than the bending angle at which the cable 2 can normally transmit the light signal. Since the light signal transmitted through the cable 2 is leaked outside at a bent point, the luminous intensity of the light signal received by the device 4 is attenuated. While the luminous intensity at this time is defined as '0', the change in heat can be judged through luminous intensities '1' or '0'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal change detecting device for monitoring a thermal change in a remote place, and more particularly to a thermal change detecting device for detecting a thermal change by a change of an optical signal.

[0002]

2. Description of the Related Art Although a conventional thermal change detecting device is not shown in the drawings, for example, a detecting mechanism using a temperature sensitive resistance element such as a thermistor or a posistor, a power source for operating this detecting mechanism, and a heat It consisted of a communication device that transmits changes.

Further, this thermal change detecting device has been used for monitoring a change in temperature at a place where it is difficult for humans to enter, for example, the vicinity of a melting furnace or a mountain refuge.

[0004]

However, the above-described conventional thermal change detecting device requires a power source in addition to the detection mechanism, and the thermal change detecting operation and the life of the device depend on the environment of the place where the device is installed. There was a problem of being influenced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal change detecting device having a long life, which does not require a power source for operation and can be stably detected in order to solve such a problem.

[0006]

A thermal change detecting device of the present invention includes an optical signal transmitting device, an optical gable for transmitting an optical signal, an optical receiving device for receiving the transmitted optical signal, and an optional optical fiber. A heat-deformable structure that holds the optical cable at a predetermined interval, and the gable is deformed by the deformation of the structure, and a change in heat is detected by transmission attenuation of an optical signal. I am trying.

[0007]

The change in shape of the structure due to the heat changes the optical signal transmission efficiency of the optical fiber, and the change in the heat can be detected.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1 (a), 1 (b) and 1 (c) are diagrams for explaining an embodiment of the thermal change detecting device of the present invention, in which (a) is a diagram showing the configuration, and (b) and (c) are thermal change detections. It is a side view and a front view showing a mechanism. As shown in FIG. 1, this thermal change detecting device includes an optical signal generating device 3 for generating an optical signal, an optical signal receiving device 4 for detecting the optical signal, an optical gable 2 for transmitting the optical signal, and an optical cable 2. Two fixtures 5 that are attached in the middle of the cable and that hold the optical cable 2 at predetermined intervals
And a structural body 1 which is fixed to the two fittings by being passed over. Further, the structure 1 has the structure shown in FIG.
As shown in (a), it is made of a shape memory alloy that is in a linearly extending state and is memorized so as to be in a bent state as shown in FIG. 1 (b) when the temperature exceeds a predetermined temperature. ing.

2 (a) to 2 (c) are side views showing in order of operation for explaining the operation of the thermal change detecting device of FIG.
Next, the operation of the heat change detection device shown in FIG. 1 will be described. First, as shown in FIG. 2, the luminous intensity of the optical signal transmitted from the optical signal transmitting device 3 to the optical signal receiving device 4 through the optical gable 2 in the state before the structure 1 has changed its shape is shown here. Set to "1". Next, as shown in FIG. 2B, the structure 1
When heat is applied to the structure 1 to reproduce the memory, when the structure 1 is heated, as shown in FIG. 2 (c), the optical cable 2 should be bent at a bending angle larger than the bending angle at which the optical cable 2 can normally transmit an optical signal. become. At this time, the optical signal transmitted through the optical cable 2 is leaked to the outside at the bent portion, and the intensity of the optical signal transmitted to the optical signal receiving device is reduced. If the luminous intensity at this time is set to "0", the change in heat can be determined by "1" and "0" of the optical signal.

Further, although the shape memory alloy is used for the structure 1 in this embodiment, after the optical fiber 2 is attached to the optical cable 2, the bending angle at which the optical fiber cannot normally transmit the light at the temperature to be detected. If the above changes are made, the reverse operation can be obtained.

FIGS. 3 (a) and 3 (b) are side views showing the order of operation for explaining another embodiment of the thermal change detecting device of the present invention. This thermal change detection device, as shown in FIG.
That is, bimetal is used for the structure 1a. Others are the same as the above-mentioned embodiment. This thermal change detector is
When moving from a room temperature state (Fig. 3 (a)) to a heated state, the degree of shape change changes depending on the temperature to be heated, as shown in Fig. 3 (b), and an optical signal reaching the optical receiver is received. The intensity of the light continuously decreases.

Since the thermal change detecting device of this embodiment can continuously detect the heating and heat reduction of the thermal change detecting mechanism, it is advantageous in that it can detect a minute temperature change as compared with the above-mentioned embodiments. is there.

[0013]

As described above, according to the present invention, a structural body which absorbs heat from the outside and changes its shape itself is prepared, and the optical cable is held at a predetermined interval by this structural body,
A change in heat can be detected by bending the optical cable due to heat deformation of the structure to attenuate the transmission of the optical signal. Therefore, according to the present invention, there is an effect that a thermal change detection mechanism having a long life and stably operating without requiring an operating power supply can be obtained.

[Brief description of drawings]

FIG. 1A is a diagram showing a configuration, and FIGS. 1B and 1C are side views and a front view showing a heat change detecting mechanism for explaining an embodiment of a heat change detecting device of the present invention. ..

FIG. 2 is a side view showing an operation sequence for explaining the operation of the heat change detection device of FIG.

FIG. 3 is a side view showing another embodiment of the thermal change detection device of the present invention in the order of operation for explaining the operation.

[Explanation of symbols]

 1, 1a Construct 2 Optical cable 3 Optical signal transmitter 4 Optical signal receiver 5 Fixture

Claims (1)

[Claims] 1. An optical signal transmitting device, an optical gable for transmitting an optical signal, an optical receiving device for receiving the transmitted optical signal, and an optical cable which holds the optical cable at an arbitrary portion of an optical fiber at a predetermined interval. And a structure that is deformed by heat,
A thermal change detecting device, characterized in that the gable is deformed by the deformation of the structure, and a change in heat is detected by attenuation of transmission of an optical signal.