JPH041530Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber device for cooling when an optical fiber is used in a high temperature environment.

[Prior art]

In recent years, optical fibers have been used as means for propagating infrared rays in radiation thermometers that measure the temperature of an object by measuring the amount of infrared rays radiated from the object. FIG. 4 is a schematic diagram showing an embodiment of the invention, in which a large number of optical fibers 41, 41, . The end surface of the light guide 42 opposite to the measurement target 43 is
It is connected to a thermometer 44. The infrared rays emitted from the measurement object 43 are transmitted to the light guide 42.
The light propagates through the optical fibers 41, 41, . . . , and the amount of light is measured by a thermometer 44, which is converted into temperature and the temperature of the object 43 to be measured is displayed.

Here, if the object to be measured 43 is a high temperature object, the optical fibers 41, 41 near the object to be measured 43
. . . The tips and the surroundings of the optical fibers 41, 41 . Although materials with excellent heat resistance were used, there were limits to their heat resistance. There, air is pumped into the optical fiber 4 in its high temperature state.
A device for cooling 1, 41, .

In FIG. 5, the structure of the light guide 42, which has one end facing the measurement object 43 and the other end connected to the thermometer 44, is the same as that shown in FIG. As shown in FIG. 5, the light guide 42 is inserted into a tube 45 having a large specific heat, such as a fluororesin tube, except for both ends thereof. Then, a pipe 45 and a light guide 42 are supplied from an air source (not shown).
Air is supplied to the periphery of the tip end of the light guide 42 through the gap between the light guide 42 and the light guide 42 (optical fibers 41, 41, . . . ) to be cooled.

[Problem that the invention attempts to solve]

With the above-mentioned cooling device, it is possible to cool the light guide (optical fiber) which has become hot, but if the tube is long (the light guide is long), it is difficult to supply air to the periphery of the tip of the light guide. Since the air pressure must be high and the optical fiber softens in a high temperature environment, there is a problem in that the optical fiber may become distorted or otherwise damaged due to the influence of the high air pressure.

[Means for solving problems]

The present invention was developed in view of the above circumstances, and its purpose is to direct the air inside the tube toward the tip of the tube (in other words, toward the tip of the optical fiber) at the tip of the tube that supplies air for cooling the optical fiber. ) In order to promote the attraction of the optical fiber to An object of the present invention is to provide an optical fiber device in which no deformation failure occurs.

The optical fiber device according to the present invention includes one or more optical fibers whose end faces directly or indirectly face a high-temperature object, and an optical fiber cooling device in which the optical fibers are inserted and ejected from the tube ends. In an optical fiber device comprising a tube through which air flows in the axial direction of the optical fiber, a tube is provided near the end face of the optical fiber of the tube along the axial direction of the optical fiber in the same direction as the flow direction of the air for cooling the optical fiber. It is characterized by comprising an attraction/promotion means for blowing air in a direction.

[Effect]

In the optical fiber device according to the present invention, cooling air is easily supplied to the periphery of the optical fiber tip at low pressure by the attraction promoting means provided near the optical fiber tip.

〔Example〕

The present invention will be specifically explained below based on drawings showing embodiments thereof. FIG. 1 is a schematic diagram showing the implementation state of the optical fiber device according to the present invention, and in the figure, 2
is a light made by converging a large number of optical fibers 1, 1, etc. whose end faces face the object 3 whose temperature is to be measured, and whose other end faces are collectively connected to a thermometer 4. It is a guide.

And the light guide 2, except for its both ends,
It is inserted into a cooling air pipe 5 that supplies cooling air. The inner diameter of the cooling air pipe 5 at the portion through which the light guide 2 is inserted is slightly larger than the diameter of the light guide 2, so a gap 6 is formed between the light guide 2 and the cooling air pipe 5. However, the inner diameter of the proximal end surface of the portion of the cooling air pipe 5 through which the light guide 2 is inserted is equal to the diameter of the light guide 2, and there is no gap.

In addition, an end of a cooling air pipe 9 whose one end is connected to an air source 10 and which penetrates a part of the circumferential surface of the cooling air pipe 5 is opened in the gap 6 on the base end side of the cooling air pipe 5. Air is supplied to the cavity 6 from a source 10 through a cooling air line 9. Here, since there is no gap on the base end surface of the cooling air pipe 5, the base end side of the light guide 2 (the opposite side of the measurement target 3)
No air flows out.

FIG. 2 is an enlarged sectional view of the vicinity of the tip of the light guide 2 (cooling air pipe 5) in FIG. 1. At the tip of the cooling air pipe 5, there is a bottomless cylindrical attracting tube 7.
However, with the bottomless part facing the measurement object 3,
It is externally fitted concentrically to the cooling air pipe 5. Further, the induction air pipe 8 whose one end is connected to the air source 20 penetrates a part of the side surface of the induction tube 7 and enters the gap between the induction tube 7 and the cooling air tube 5, and the tube end is It surrounds the cooling air pipe 5 and forms an annular shape. The pipe end position coincides with the pipe end position of the cooling air pipe 5 and the side end surface position of the induction cylinder 7.

Next, a specific procedure for measuring the temperature of the object to be measured 3 will be explained. Infrared rays emitted from the object to be measured 3 propagate through the light guide 2 (optical fibers 1, 1, . . . ) whose end face faces the object to be measured 3, and enter the thermometer 4. The thermometer 4 measures the amount of incident light, converts the measured value into a temperature, and displays the temperature. During this temperature measurement, air is supplied from the air source 10 through the cooling air pipe 9 and the gap 6 from the base end periphery of the light guide 2 to the tip end periphery, and is ejected forward from the opening of the cooling air pipe 5. . The light guide 2 (optical fibers 1, 1...) is cooled by this air.

Here, air is supplied from the air source 20 through the induction air pipe 8, and is ejected forward from the end opening. Then, as the air is ejected from the induced air pipe 8, the vicinity of the opening end of the cooling air pipe 5 becomes negative pressure, and as a result, the air inside the cooling air pipe 5 is attracted to the tip of the light guide 2. Easily supplied to the periphery. Therefore, even if the air in the cooling air pipe 5 is at a low pressure, the cooling air is easily supplied to the periphery of the tip of the light guide 2 through the gap 6, and the light guide 2 (optical fibers 1, 1, . . . ) is Can be cooled.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the cooling air attraction promotion means for the cooling air pipe 5 provided at the tip of the cooling air pipe 5. FIG.

In the case of FIG. 3, a nozzle 21a is installed at the tip of the
An ejector 21 for inducing cooling air having a nozzle 21a facing the cooling air path direction within the gap 6 is provided so as to penetrate a part of the circumferential surface of the cooling air pipe 5. When a small amount of air is injected into the gap 6 from the nozzle 21a, the ejector effect (the injected air draws in surrounding air and creates a large air flow) causes the cooling air in the cooling air pipe 5 to flow into the light guide 2. It is easily supplied to the periphery of the tip.

Although this embodiment describes a light guide used for temperature measurement, it goes without saying that an image guide or a fiberscope can be used in exactly the same way to cool the optical fiber while keeping the cooling air pressure low. .

〔effect〕

As described in detail above, in the optical fiber device according to the present invention, cooling air can be easily supplied to the periphery of the tip of the optical fiber without increasing the pressure of the cooling air. Further, even with low-pressure cooling air, the optical fiber can be sufficiently cooled, so there is no risk of deformation of the optical fiber due to the air pressure of the cooling air, and the present invention has excellent effects.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the implementation state of the present invention, Figure 2
The figure is an enlarged sectional view of the tip part in Figure 1,
4 and 5 are schematic diagrams of conventional devices. 1...Optical fiber, 2...Light guide, 3...
...Measurement object, 4...Thermometer, 5...Cooling air pipe, 6...Gap, 7...Attraction tube, 8...Attraction air tube, 9...Cooling air piping, 10, 20...Air Source, 21...Ejector for cooling air induction, 21
a... Nozzle.

Claims (1)

[Claims for Utility Model Registration] One or more optical fibers whose end faces directly or indirectly face a high-temperature object, and air for cooling the optical fibers inserted through the optical fibers and blown out from the ends of the optical fibers. In an optical fiber device, the optical fiber device includes a tube in which the air for cooling the optical fiber flows in the vicinity of the end face of the optical fiber in the tube along the axial direction of the optical fiber in the same direction as the flow direction of the optical fiber cooling air. 1. An optical fiber device comprising an attraction/promotion means for blowing out air.