JP3032665B2 - Metal tube optical fiber package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal tube optical fiber package in which an optical fiber is inserted through a metal tube.

[0002]

2. Description of the Related Art In recent years, a metal tube optical fiber in which an optical fiber is inserted into a metal tube has a small diameter, and is excellent in light transmission stability under a hydrogen environment, under side pressure, under water pressure, under a tensile load, and the like. It is used as a strong optical fiber core, an optical fiber cord, or an optical fiber cable. The metal tube optical fiber usually has an outer diameter of 0.5 to 5 mm and a thickness of 0.05 to
A single-core or multiple-core optical fiber is inserted through a 0.5 mm metal tube. As a metal tube, a stainless steel tube, a copper tube, or the like is used. Further, when the metal tube optical fiber is exposed to a high temperature, excessive tension may be generated in the optical fiber due to a difference in thermal expansion coefficient between the metal tube and the optical fiber. In such a case, the transmission loss of the optical fiber may increase or break. Therefore, when an optical fiber is inserted into a metal tube, the optical fiber is made slightly longer than the metal tube and inserted with a swell. The extra length of the optical fiber is called extra length.

[0003] For convenience of storage and transportation, a long metal tube optical fiber exceeding several hundred meters is wound on a reel to form a package. FIG. 5 shows an example of such a package. The metal tube optical fiber 1 has a small diameter,
Since the reel 51 has a diameter of 3 mm,
Relatively small, from 00mm to 500mm, made of plastic, metal or wood.

As another package of a wire such as a welding wire, a steel wire, or an electric wire, a so-called pail pack in which the wire is housed in a cylindrical container is known (for example, Japanese Patent Publication No. 54-39191). Bulletin, Tokuhei 1-177
No. 94).

[0005]

As described above, conventionally, a metal tube optical fiber is wound on a reel to form a package. However, the metal tube optical fiber package has a unique problem not found in welding wires and electric wires.
That is, the winding cannot be performed unless tension is applied to the metal tube when the reel is wound. Due to this tension, the metal tube is elongated, and the extra length is different depending on the optical fiber insertion, reel winding, and use, and the transmission loss changes. In the case of measurement using an optical fiber, a change in transmission loss contributes to an error. In addition, when the metal tube optical fiber is wound around a reel with the reel axis being horizontal, so-called vertical winding, the optical fiber in the metal tube gradually moves to the winding start end of the reel, and a uniform extra length is provided over the entire length of the metal tube optical fiber. I can't get a length.

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal tube optical fiber package capable of holding a required extra length of an optical fiber uniformly over its entire length.

[0007]

According to the metal tube optical fiber of the present invention, the optical fiber is inserted into the metal tube with an extra length.
The metal tube optical fibers are sequentially stacked in a coil shape from below and housed in a cylindrical container.

[0008] The inner diameter of the coil of the metal tube optical fiber is desirably 250 mm or more from the viewpoints of prevention of curling, straightness returnability, and insertion and exit of the coil. In order to prevent collapse of the load during transportation and to smoothly pull out the optical fiber from the metal tube, the cylindrical container is desirably a double cylindrical container including an inner tube and an outer tube. Further, when inserting the metal tube optical fiber into the cylindrical container, it is preferable to insert the metal tube optical fiber in a floral pattern while rotating the cylindrical container.

[0009] It is desirable that the stored metal tube optical fiber be in a state in which it is not bent and has a straight line return property.
Specifically, when inserting the metal tube optical fiber into the cylindrical container, the insertion device uses the insertion device for one turn of the metal tube optical fiber.
Insert while giving a twist within the elastic range at a rate of 60 °. When the metal tube optical fiber thus inserted is fixed to the cylindrical container and pulled out, a 360 ° torsion stress is generated for one turn in the opposite direction to the insertion, and the twist given to the metal tube optical fiber is reduced. Cancel each other out. As a result, the metal tube optical fiber is drawn out without being wound, and the metal tube optical fiber is drawn out substantially in a linear state.

[0010] A connector may be attached to each of a front end and a rear end of the metal tube optical fiber drawn out of the cylindrical container. In the package to which the connector is attached, the metal tube optical fiber can be used by being pulled out by a required length and connected to required equipment.

[0011]

Since the metal tube optical fibers are sequentially stacked in a coil shape from below and stored in the cylindrical container, almost no tension is generated in the metal tube optical fibers. As a result, since the metal tube does not extend, the extra length when the optical fiber is inserted through the metal tube is maintained as it is.

[0012]

FIG. 1 is a longitudinal sectional view showing an example of a metal tube optical fiber package according to the present invention. The cylindrical container 11 has a double structure including an inner cylinder 12 and an outer cylinder 14. A rear end outlet 15 is provided near the bottom of the outer cylinder 14, and a rear end guide tube 16 is attached thereto. A conical hood 18 is fixed to the top of the cylindrical container 11 with a holding belt 21. Food 1
A front end take-out port 19 is provided at the top of 8, and a front end guide tube 23 is attached here.

In the cylindrical container 11 configured as described above,
The metal tube optical fiber 1 is housed in a coil shape around the inner cylinder 12. The coil 5 has a floral pattern as shown in FIG. An annular holding plate 25 is provided on the upper surface of the coil 5.
Has been posted. Metallic tube optical fiber 1 in cylindrical container 11
When the metal tube optical fiber 1 is pulled out from the coil 5, the metal tube optical fiber 1 is sequentially loosened from the top of the coil 5 to prevent the metal tube optical fiber 1 from being entangled. Since the metal tube of the metal tube optical fiber 1 has a small diameter and a small wall thickness, the weight greatly varies depending on the size of the metal tube. You need to choose.

The front end 2 of the metal tube optical fiber 1 is pulled out from an outlet 19 of the hood 18 through a guide tube 23, and a connector 27 is attached to the end. When the metal tube optical fiber 1 is used for measurement, for example, a processing circuit for a detection signal is connected to the connector 27. When the front end portion 2 of the metal tube optical fiber 1 is pulled out from the cylindrical container 11, the metal tube optical fiber 1 rises while spiraling around the inner cylinder 12, and is led out by the guide tube 23. The guide tube 23 prevents the metal tube optical fiber 1 from bending (kinking).

The rear end 3 of the metal tube optical fiber 1 is
4 is pulled out from the outlet 15 through the guide tube 16, and a connector 28 is attached to the rear end. A detector or the like is connected to the connector 28.

FIG. 3 shows a cylindrical container 1 of a metal tube optical fiber 1.
1 shows a method of loading the data into the memory. The metal tube optical fiber 1 is fed by a take-up capstan 31 and a pressing roller 32 and guided to a rotary fryer 34. The rotary fryer 34 is formed of a curved tube and is driven to rotate about a vertical axis. On the other hand, the cylindrical container 11 is
The turntable 36 is also driven to rotate about a vertical axis. The metal tube optical fiber 1 drops from the lower end of the rotary fryer 34 while spiraling into the cylindrical container 11, and forms the coil 5 around the inner cylinder 12. By adjusting the relative relationship (rotation center position, rotation radius, rotation speed, and the like) of the rotary fryer 34 with respect to the cylindrical container 11, the floral-shaped coil 5 as shown in FIG. 2 can be formed. Further, the metal tube optical fiber 1 is accommodated in a state where it is not bent and has a straight line returning property. Since the loading start end of the metal tube optical fiber 1 comes to the bottom of the cylindrical container 11, the loading start end of the metal tube optical fiber 1 is taken out from the outlet 15 at the bottom, and is wound around the outer peripheral surface of the outer tube 14 by a required length. .

FIG. 4 is a view for explaining a method of using the metal tube optical fiber package in a geothermal power plant. The metal tube optical fiber package 10 is placed near the use site, that is, near the boring section 8. The distal end of the metal tube optical fiber 1 is pulled out from the top of the cylindrical container 11 and guided to the guide tube holder 42 of the driving device 41 via the guide tube 23. Next, the driving roller 43 is driven to feed the metal tube optical fiber 1 to the boring unit 8 via the guide roller 44. The rear end 3 of the metal tube optical fiber 1 is pulled out of the cylindrical container 11 and connected to a measuring device 46 including a signal processing circuit, a display device, and the like. The measuring device 46 measures the temperature distribution in the bowling unit 8 based on a signal from the metal tube optical fiber 1 inserted into the bowling unit 8.

[0018]

In the metal tube optical fiber package of the present invention, almost no tension is generated in the metal tube optical fiber, so that the required extra length is maintained uniformly over the entire length.

Metal tube The thickness of the metal tube of the optical fiber is generally 0.05 to 0.5 mm, particularly 0.05 to 0.2 mm.
With a thin wall of mm, the metal tube may be crushed due to the tension at the time of reel winding. However, according to the present invention, since almost no tension is generated, the metal tube does not collapse. Further, when the metal tube optical fiber is used continuously while being unwound from the reel, the connector on the reel side rotates in accordance with the rotation of the reel, so that a rotary joint or the like must be used. For this reason, not only is the equipment using the metal tube optical fiber expensive, but also the connection loss increases. In the present invention, a coil-shaped metal tube optical fiber may be pulled out from the cylindrical container, so that a rotary joint or the like is unnecessary. Therefore, there is also an advantage that the equipment cost and the connection loss can be reduced.

Further, in the conventional package, when rewinding from the reel, the winding at the time of winding the reel remains, and in an extreme case, the metal tube optical fiber becomes a spring. However, according to the present invention, it is possible to prevent the metal tube optical fiber from being springed by eliminating the curl in the metal tube optical fiber and giving the straight line returnability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a metal tube optical fiber package of the present invention.

FIG. 2 is a cross-sectional view of the package shown in FIG.

FIG. 3 is a view for explaining a method of housing a metal tube optical fiber in a cylindrical container to form the package.

FIG. 4 is a diagram illustrating an example of a method of using the package.

FIG. 5 is a longitudinal sectional view showing a conventional metal tube optical fiber package.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal tube optical fiber 5 Metal tube optical fiber coil 8 Boring part 10 Metal tube optical fiber package 11 Cylindrical container 12 Inner tube 14 Outer tube 16 Guide tube 18 Hood 23 Guide tube 25 Pressing plate 27, 28 Connector 31 Take-off cap stand 34 rotating flyer 36 turntable 41 driving device 46 measuring device 51 reel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model 2-30905 (JP, U) Japanese Utility Model 2-81508 (JP, U) Japanese Utility Model 58-123861 (JP, U) Japanese Utility Model Utility Model 160671 (JP, U) Table 1-503701 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 54/56-54/88 B65H 57/00-57/28

Claims (3)

(57) [Claims] In a metal tube optical fiber package in which an optical fiber is inserted into a metal tube, the optical fiber is placed inside the metal tube.
A metal tube optical fiber package characterized in that metal tube optical fibers inserted with an extra length are sequentially stacked in a coil shape from below and housed in a cylindrical container. 2. The metal tube optical fiber package according to claim 1, wherein the stored metal tube optical fiber has no recoil and has a straight line return property. 3. The metal tube optical fiber package according to claim 1, wherein connectors are respectively attached to a front end and a rear end of the metal tube optical fiber drawn out of the cylindrical container.