JP3181318B2 - Method and apparatus for manufacturing metal tube coated optical fiber cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for continuously producing an optical fiber cable coated with a metal tube.
In particular, it relates to prevention of peeling of a primary coating layer of an optical fiber.

[0002]

2. Description of the Related Art A metal tube-coated optical fiber cable comprises one or a plurality of optical fibers and a metal tube for covering the optical fiber. The outer metal tube functions as a strength member for protecting the optical fiber. In particular, if a space is secured between the metal tube and the optical fiber, even if tension or lateral pressure acts on the metal tube-coated optical fiber cable, tension or the like is prevented from acting on the optical fiber and the optical fiber is prevented. Of optical transmission loss can be suppressed. When the space is filled with an appropriate substance, the space can be provided with environmental protection such as moisture proof and water proof.

[0003] A method for continuously producing such an optical fiber cable coated with a metal tube is disclosed in, for example, JP-A-57-64706.
It is disclosed in JP-A-64-35514 and JP-A-64-52104. According to the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 57-64706, a continuously fed metal strip is formed into a tubular shape, and a butt portion is welded to form a metal tube. Insert a straight pipe into the metal pipe during the molding process, guide the optical fiber through the pipe, and protect the heat-sensitive optical fiber at the welding position by heat shielding the pipe with heat. It is loaded in the tube.

Further, in the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 52104/1988, a metal tube already formed or formed by welding is wound in a coil shape, and a relative position is formed between the metal tube and the optical fiber. The optical fiber is inserted into the metal tube while giving a proper vibration. In order to facilitate insertion of the optical fiber into the metal tube, a lubricant is previously attached to the optical fiber.

[0005]

When the optical fiber is introduced by simply introducing the optical fiber into the metal tube as described above, the butt portion at the upper portion of the metal tube is welded by TIG welding, laser welding, or the like. When the metal pipe is sealed by welding, the welding spatter accumulates on the inlet pipe, and if the operation is performed for a long time, the deposited welding spatter may come into contact with the inner wall of the metal pipe and cause poor welding. For this reason, in particular, it has not been possible to continuously manufacture a long metal tube-coated optical fiber having a length of 5 km or more. This phenomenon becomes more significant as the diameter of the metal tube becomes smaller. That is, even if the diameter of the metal tube is reduced, it is physically limited to reduce the diameter of the introduction tube accordingly. Furthermore, if the gap between the metal pipe and the inlet pipe is not sufficiently ensured, even if the inlet pipe is used, the effect of welding heat will affect the optical fiber, which may cause thermal damage to the optical fiber passing through the inside. There was also.

When the optical fiber is loaded into the metal tube through the introduction tube, the optical fiber comes into contact with the introduction tube and the metal tube, and the primary coating layer of the optical fiber is peeled off by this contact. When the primary coating of the optical fiber is peeled off, the tensile strength of the optical fiber is remarkably reduced, which causes breakage. In addition, the peeled coating is deposited in the introduction pipe and causes a passage obstacle of the optical fiber. Since this passage obstruction causes a change in the tension of the optical fiber, when the excess length is controlled by adjusting the tension as shown in, for example, Japanese Patent Application Laid-Open No. 61-17447, a change in product quality causes a large problem. . These effects are remarkable at a place where the introduction pipe or the metal pipe is curved, and is particularly remarkable when the diameter of the introduction pipe is small or when the introduction pipe is manufactured continuously for a long time. In such a case,
As shown in JP-A-64-52104, if a lubricant is applied to an optical fiber and then the optical fiber is passed through the introduction tube, the contact between the optical fiber and the introduction tube can be reduced.

[0007] However, if an excessive amount of lubricant is attached to the optical fiber, the lubricant is deposited in the introduction pipe, which causes a problem.
The same problem as the adverse effect caused by peeling of the next coating layer occurs. In addition, some lubricants are flammable substances, and in some cases, it is required to completely shield the heat at the welded portion as in the case of the optical fiber.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a lubricant is attached to an optical fiber to prevent the primary coating layer from peeling off through an introduction pipe, and to provide a heat-sensitive optical fiber. And a method of manufacturing a metal tube-coated optical fiber cable capable of continuously manufacturing a metal tube-coated optical fiber cable for a long period of time by effectively protecting the lubricant from welding heat. Is what you do.

[0009]

A method of manufacturing a metal tube-coated optical fiber cable according to the present invention comprises the steps of forming a metal strip into a tube, welding a butt portion to form a sealed metal tube, and forming the metal strip into a sealed metal tube. In a method for manufacturing a metal tube-coated optical fiber cable in which an optical fiber is loaded through an introduction tube inserted into a tube, an optical fiber or an optical fiber bundle having a lubricating substance attached thereto is introduced into the introduction tube, and the optical fiber or the optical fiber is introduced.
Capstan around which metal tube with fiber bundle is wound
Between the metal tube and the optical fiber or optical fiber bundle
Give the metal tube an optical fiber or optical fiber
Reduce the tension of the ive bundle with the capstan and
Tube and optical fiber or optical fiber bundle at the exit side of the
Optical fiber or optical fiber
It is characterized in that the extra length of the bundle is controlled .

[0010] The outer diameter of the introduction pipe is smaller than the inner diameter of the metal pipe.
It is preferable that the introduction pipe is positioned on the side opposite to the welding surface of the metal pipe, and is inserted into the metal pipe so that the distance between the introduction pipe and the welding surface of the metal pipe is always kept constant. Further, it is preferable to remove excess lubricating substance before inserting the optical fiber to which the lubricating substance is attached into the introduction tube.

Further, the number of optical fibers may be one or more, and a gas or a filling substance may be injected into the metal tube together with the optical fibers from the introduction tube.

Further, the apparatus for manufacturing a metal tube-coated optical fiber cable according to the present invention comprises means for forming a metal strip into a tube and welding a butt portion to form a sealed metal tube;
In a manufacturing apparatus for a metal tube-coated optical fiber cable having an introduction tube inserted into a sealed metal tube and guiding an optical fiber into the sealed metal tube, a lubricant supply for adhering a lubricating substance to the optical fiber guided by the introduction tube. for example Bei means, light off
Metal tube with fiber or optical fiber bundle wound
Metal tube and optical fiber or light at the entrance of the capstan
Give a difference in the tension of the fiber bundle, and
Reduce the tension of the fiber or fiber optic bundle with the capstan.
And the metal tube and optical fiber or
Optical fiber bundles by providing a difference in the amount of expansion of the optical fiber bundle.
It is characterized in that the excess length of the fiber or optical fiber bundle is controlled .

Further, it is preferable to provide an excess lubricant removing means for removing excess lubricant from the optical fiber passing through the lubricant supply means.

Further, the excess lubricant removing means is provided at the optical fiber inlet of the introduction pipe, and is constituted by means for reversely flowing the gas or the filling material filled in the metal pipe in a direction opposite to the traveling direction of the optical fiber. Good.

[0015]

According to the present invention, by utilizing the elasticity at the curved portion of the introduction pipe, the introduction pipe is elastically pressed against the inner wall on the side opposite to the welded surface of the metal pipe at the welding position and in the vicinity thereof, and The space between the welding surface of the pipe and the inlet pipe is widened to reduce the effect of welding heat.

Further, by introducing, for example, an inert gas or a cooling gas for securing a welding atmosphere or a filling material for filling the space of the metal tube together with the optical fiber from the introducing tube, these gases or the filling material can be used. The effect of welding heat on optical fibers and the like can be further reduced.

Further, since the introduction pipe is curved, the contact between the optical fiber and the inner wall of the introduction pipe becomes remarkable. Normally, since a backward tension is applied to the optical fiber, this contact causes the primary coating layer of the optical fiber to peel off significantly. Therefore, a lubricating substance is attached to the optical fiber before insertion into the introduction tube, and the optical fiber and the inner wall of the introduction tube are brought into contact with each other via the lubricating substance to prevent the primary coating layer of the optical fiber from peeling off.

Further, when an excessive lubricating substance is attached to the optical fiber, the same effect as when the primary coating layer of the optical fiber is peeled off occurs. This effect is particularly remarkable when the lubricating substance is a solid particulate or highly viscous substance, and particularly remarkable when the inlet tube is curved or small in diameter. Therefore, before inserting the optical fiber to which the lubricating substance is attached into the introduction pipe, the excessive lubricating substance is removed to prevent the excessive lubricating substance from remaining and stagnating in the introduction pipe. Also, if a flammable lubricating substance is used, even if the temperature of the introducing pipe rises in the vicinity of the welding position, there is no excess lubricating substance in the introducing pipe. Stave to a minimum.

When a gas or a filling substance is introduced into the metal pipe through the introduction pipe, a part of the gas or the filling substance is caused to flow from the inlet of the introduction pipe in a direction opposite to the traveling direction of the optical fiber to overflow, so that the gas that has flowed out. The surface of the optical fiber can be wiped with a filler or a filler to remove excess lubricant. Even when the gas is not introduced into the metal tube through the introduction tube, the gas adheres to the surface of the optical fiber even if the gas flows in the opposite direction to the traveling direction of the optical fiber between the introduction tube and the lubricant supply means. Excess lubricating material can be removed.

[0020]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. As shown in the figure, an apparatus for manufacturing a metal tube-coated optical fiber cable includes a metal strip 1 wound in a coil shape.
a, a first forming roll group 3, a second forming roll group 4, a first forming roll group 3 and a second Between the forming roll group 4 or the first
And an optical fiber introducing device 5 for introducing an optical fiber or an optical fiber bundle (hereinafter, referred to as an optical fiber) 2 which is provided in front of the forming roll group 3.

A lubricant supply device 7 for applying a lubricant to the optical fiber 2 is provided between the optical fiber introducing device 5 and a dancer roll stand 6 for adjusting the tension of the optical fiber 2. As shown in FIG. 2, the lubricant supply device 7 is provided on a container 72 having a passage 71 for the optical fiber 2 and containing a lubricant 76, and provided on the outlet side of the container 72. A removing device 73 for flowing gas in the opposite direction to remove excess lubricant. This lubricant supply device 7
As the lubricant for adhering the lubricant to the optical fiber 2, a powdery lubricant such as carbon, molybdenum disulfide, talc or the like, or a liquid lubricant such as silicon oil is used. When the liquid lubricant is used, the liquid lubricant in the container 72 is adhered to the surface of the optical fiber 2 while being circulated by the circulation pump 74 as shown in FIG. When a powdered lubricant is used, the powdered lubricant is stored in a container 72 having a lid 75 that can be opened and closed as shown in FIG. 3, and the lubricant is attached through the optical fiber 2 therein. . In any case, when the amount of the lubricant is reduced, the lubricant is refilled.

At the stage subsequent to the second forming roll group 4, a metal tube 1 is provided.
A welding device 8 for welding the butted portions is provided. When the diameter of the metal tube 1 is small, it is desirable that the welding device 8 applies beam welding such as laser light or electron beam. In this embodiment, a carbon dioxide laser welding device is used as the welding device 8. In the subsequent stage of the welding device 8, an inspection device 9 for inspecting the traction speed of the welded metal tube 1 and the presence or absence of a welding defect, and reducing the diameter of the welded metal tube 1 to a metal tube 1b having a predetermined outer diameter. Diameter reducing means 10 and capstan 1
1, a dancer roll 12 and a winder 13 are connected in series.

An optical fiber introducing device 5, as shown in FIG. 4, a guide tube 51 for guiding the optical fiber 2, a gas and an optical fiber 2 for cooling a welding portion and adjusting a welding atmosphere, and the like.
And manifold 5 having a supply pipe 53 for supplying a filling substance 52 filling the space between the metal pipe 1 and the metal pipe 1
4 and an introduction pipe 55 which is attached to the other end and bent in a substantially L-shape with a constant curvature. This introduction pipe 55
When the welding device 8 is formed of a carbon dioxide laser welding device, the welding device 8 is made of copper or a copper alloy having a high reflectance of carbon dioxide laser light, and is formed to have a constant curvature.
The leading end of the introduction pipe 55 passes through the welding device 8 and has a diameter reducing means 1.
It is inserted up to just before 0. Then, at the laser light irradiation position 14 of the welding device 8, the introduction pipe 55 is pressed against the inner wall of the metal pipe 1 on the opposite side to the laser light irradiation position 14 to introduce the laser light.
The distance between the pipe 55 and the welding surface of the metal pipe 1 is always kept constant.
It is fixed so that. When the introduction pipe 55 is pressed and pressed, the entirety of the introduction pipe 55 is pressed downward and fixed, so that the distal end of the introduction pipe 55 is attached to the metal pipe 1 by utilizing the elastic force of the curved portion bent at a constant curvature. Can be pressed. It should be noted that a special support mechanism, for example, a part of the upper part of the introduction pipe 55 as shown in FIG. A spacer 56 made of a copper piece may be fixed to the inner wall of the metal tube 1 on the opposite side of the laser beam irradiation position 14 using the spacer 56.

In the manufacturing apparatus configured as described above, the metal strip 1a wound in a coil shape is pulled by the capstan 11 while the tension is adjusted by the dancer roll stand 15, and the first forming roll is formed. The primary molding is performed in a substantially U-shape in the group 3. Then, it is formed into a tubular shape by the second forming roll group 4, and is formed into a metal tube 1 having an abutting portion on an upper portion. An optical fiber introducing device 7 is
The optical fiber 2 is continuously fed through the optical fiber 2, and is inserted while moving along the inner wall of the curved portion 55a of the introduction tube 55.
At the same time, a cooling gas or an inert gas is supplied from a supply pipe 53 connected to the manifold 54 of the optical fiber introduction device 7, and is sent from the introduction pipe 6 into the metal pipe 1. When the optical fiber 2 is introduced through the introduction pipe 55, the surface of the optical fiber 2 whose tension is adjusted by the dancer roll stand 6 has
Since the lubricant is attached by the lubricant supply device 7, even if the optical fiber 2 is sent while being in contact with the introduction pipe 55, the friction coefficient between the optical fiber 2 and the introduction pipe 55 can be reduced. In addition, the primary coating of the optical fiber 2 can be prevented from peeling off.

In this state, laser light is radiated from the welding device 8 to the butted portion on the upper portion of the metal tube 1 and welded, thereby forming the sealed metal tube 1 containing the optical fiber 2 therein. When welding the abutting surface of the metal tube 1, the introduction tube 55 for guiding the optical fiber 2 is pressed against the inner wall of the metal tube 1 on the side opposite to the welding surface 14, so that the tube is continuously formed and fed. Even if vibration occurs in the metal pipe 1 to be introduced, the introduction pipe 55 is always
4, and the distance between the introduction pipe 55 and the welding surface can always be kept constant. Therefore, the thermal effect of welding on the introduction pipe 55 and the optical fiber 2 guided by the introduction pipe 55 can be reduced. Further, by the cooling gas supplied from the supply pipe 53,
Since the introduction pipe 55 and the optical fiber 2 near the welded portion are cooled, the thermal influence of welding can be further reduced, and the environmental temperature of the optical fiber 2 near the welding position can be suppressed to about 110 degrees Celsius or less. Although the case where the butted portion of the metal tube 1 is laser-welded has been described, the thermal effect of welding can be similarly reduced when welding is performed by TIG welding or the like.

The introduction pipe 55 is pressed against the inner wall opposite to the welding surface 14 so that its position does not fluctuate and the distance from the welding surface can always be kept to a maximum.
Even if welding spatter accumulates on the upper surface of the metal pipe 5, it does not come into contact with the metal pipe 1, and the operation can be performed for a long time.

After the welded portion or the like of the metal tube 1 containing the optical fiber 2 is inspected by the inspection device 9, the diameter is reduced to a predetermined outer diameter by the diameter reducing means 10. The metal tube 1b is wound around the rotating capstan 11 a plurality of times, and is pulled by frictional engagement with the surface of the capstan 11. The optical fiber 2 loaded in the metal tube 1b is pulled together with the metal tube 1b by frictional engagement with the inner surface of the metal tube 1b. Metal tube 1b
Is pulled by the capstan 11, the tension between the metal tube 1b and the optical fiber 2 gradually decreases in the path from the entrance side to the exit side of the capstan 11. Thus, the metal tube 1b
In addition, the tension of the optical fiber 2 is reduced by the capstan 11 so that the metal tube 1b and the optical fiber 2 at the exit side of the capstan 11 have a difference in the amount of elongation to control the extra length.

The metal tube-coated optical fiber cable leaving the capstan 11 passes through the dancer roll 12 and is taken up by the winder 1.
It is wound on 3. The main function of this dancer roll 12 is
The tension of the metal tube coated optical fiber cable on the exit side of the capstan 11 and the tension on the entrance side of the winder 13 are adjusted. It is determined by the winding speed of the machine 13.

As described above, in this embodiment, the excess length of the metal tube-coated optical fiber cable is controlled by adjusting the tension of the optical fiber 2 and the metal strip 1a or the metal tube 1 relatively. ing. Therefore, since the operation cannot be performed with the tension of the optical fiber 2 set to zero in principle, a certain amount of tension is applied to the optical fiber 2. For this reason, when introducing the optical fiber 2,
The optical fiber 2 comes into strong contact with the curved portion 55a of the introduction tube 55. Normally, the primary coating layer of the optical fiber 2 is peeled off by this contact, and a large amount of the primary coating layer is deposited in the introduction pipe 55 and remains. When the primary coating layer thus peeled remains, the tension of the optical fiber 2 fluctuates, and the accuracy of the extra length control by the tension adjustment is reduced. Further, when the primary coating layer of the optical fiber 2 is peeled off, the tensile strength of the optical fiber 2 is remarkably reduced, which causes breakage. Therefore, before sending the optical fiber 2 to the introduction pipe 55, a lubricant is attached to the surface thereof to prevent the optical fiber 2 from directly contacting the inner wall of the introduction pipe 55, and to prevent the optical fiber 2 from contacting the inner wall of the introduction pipe 55. The coefficient of friction is reduced.

When an excessive amount of lubricant is attached to the optical fiber 2, the same effect as when the primary coating layer of the optical fiber 2 is peeled off occurs. This effect is particularly remarkable when the lubricant is a solid particulate or highly viscous substance. Therefore, before inserting the optical fiber 2 to which the lubricant has adhered into the introduction pipe, the removing device 73 removes excess lubricant by flowing gas in a direction opposite to the traveling direction of the optical fiber 2 to remove excess lubricant. Is prevented from remaining in the introduction pipe 55 and stagnating. Further, when a flammable lubricant is used, even if the temperature of the introduction pipe 55 rises in the vicinity of the welding position, there is no excessive lubricant in the introduction pipe 55, so that the combustion of the lubricant, etc. Can be minimized.

The above embodiment is directed to the case where excess lubricant adhering to the optical fiber 2 is removed by using a removal gas flow in a removal device 73 provided immediately after the container 72 of the lubricant supply device 7. As described above, the excess lubricant may be directly removed at the entrance of the optical fiber introduction device 5 by a cooling gas or a filler filling the space between the metal tube 1 and the optical fiber 2.

For example, as shown in FIG. 5, while feeding the optical fiber 2 to which the lubricant has been attached from the guide tube 51 of the optical fiber introducing device 5, the cooling or the power is supplied from the supply tube 53.
A gas or filling 52 for the gas is supplied. While introducing the optical fiber 2 and gas into the metal tube 1 through the introduction tube 55, a part of the gas is ejected from the entrance side of the guide tube 51, or the filling material is caused to overflow into the container 57. Excessive lubricant attached to the surface of the optical fiber 2 sent to the guide tube 51 can be removed. The filling material overflowing in the container 57 may be collected by the suction pipe 58.

In the above embodiment, the case where the gas or the filler 52 is separately supplied from the supply pipe 53 has been described. However, the gas and the filler can be supplied simultaneously. For example, as shown in FIG. 6, a gas introduction joint 511 to which a gas supply pipe 510 is connected is provided above a guide pipe 51a having a filler overflow hole 59. The filler 52 is supplied from the supply pipe 53 while feeding the optical fiber 2 to the curved introduction pipe 55 through the gas introduction joint 511 and the guide pipe 51 a, and is sent into the metal pipe 1 through the introduction pipe 55. The gas is supplied from the gas supply pipe 510 while causing a part of the filler to overflow from the overflow hole 59 of the guide pipe 51a, and is ejected from the inlet of the gas introduction joint 511 into which the optical fiber 2 is introduced. By simultaneously supplying the gas and the filler as described above, it is possible to remove excess lubricant attached to the optical fiber 2 by jetting out the gas and then remove the remaining excess lubricant by overflow of the filler. Thus, the optical fiber 2 having a thin layer of a lubricant attached to the surface thereof can be sent to the introduction tube 55.

In each of the above-described embodiments, a case has been described in which the single-tube introduction tube 55 is used. However, as shown in FIG.
An introduction tube 55 composed of a double tube 51 and a filler introduction tube 552 that covers the optical fiber introduction tube 551 may be used. Then, the guide tube 51, the gas supply tube 510 and the optical fiber introduction tube 551 are connected by the manifold 54, and the supply tube 53 for supplying the filling material and the introduction tube 55 for the filling material.
2 and the optical fiber 2 and the cooling gas or the inert gas are supplied to the metal tube 1 by the optical fiber introducing pipe 551.
While the gas is being introduced into the inside, the excess filler adhering to the surface of the optical fiber 2 with a part of the gas can be removed and eliminated. In this case, the filler supplied from the supply pipe 53 is sent into the metal pipe 1 through the space between the optical fiber introduction pipe 551 and the filler introduction pipe 552, so that the optical fiber 2 is thinned.
It is not affected by the viscous resistance of the filler when passing through 51, and can be inserted into the metal tube 1 while maintaining a constant tension, and the extra length of the optical fiber can be controlled with high precision.

In the embodiment shown in FIG. 7, the case where the gas supply pipe 510 is directly connected to the manifold 54 has been described. However, as shown in FIG. 8, the gas supply pipe 510 is directly connected to the guide pipe 51. Even in this case, the same operation as the above embodiment can be obtained.

[0036]

According to the present invention, as described above, the optical fiber
Key around which a metal tube into which a fiber bundle or optical fiber bundle is introduced is wound.
Metal tube and optical fiber or optical fiber at the entry side of the capstan
Give the fiber bundle a difference in tension, and
Or reduce the tension of the optical fiber bundle with a capstan,
Metal tube and optical fiber or light at the exit side of the capstan
By giving a difference in the elongation of the fiber bundle,
Controls the extra length of the optical fiber bundle.
The extra length of the fiber can be controlled with high accuracy. Also,
Optical fiber or optical fiber with lubricating substance attached to the inlet tube
Optical fiber in metal tube by introducing bundle
To control the excess length of the optical fiber.
Can be Furthermore, by introducing an inert gas, a cooling gas, and a filling material for filling the space of the metal tube together with the optical fiber from the introduction pipe together with the optical fiber, these gases or the filling material are used to fill the optical fiber or the like. The effect of the welding heat can be further reduced.

Further, the introduction pipe having the curved portion is placed at the welding position.
Pressure is applied elastically to the inner wall of the metal tube opposite to the weld surface.
And make sure that the inlet pipe is always on the opposite side of the welding surface.
The maximum distance between the inlet pipe and the welding surface
Can be held in the guide tube and guided by the guide tube
Reduce the thermal effect of welding on optical fiber and lubricant,
Damage due to heat can be reliably prevented.

Also, always keep the distance between the inlet pipe and the welding surface at the maximum.
Of the welding pipe on the upper surface of the introduction pipe.
The metal pipe 1 does not come in contact with the
It can operate stably for a while.

Further, since the introduction tube is curved, the contact between the optical fiber and the inner wall of the introduction tube becomes remarkable. However, before the insertion into the introduction tube, a lubricating substance is attached to the optical fiber, and the optical fiber and the inside of the introduction tube are attached. The primary coating layer of the optical fiber can be prevented from peeling off by bringing the wall into contact with the lubricating substance and reducing the coefficient of friction between the optical fiber and the inner wall of the introduction tube.

When an excessive lubricating substance adheres to the optical fiber, the same effect as when the primary coating layer of the optical fiber peels off occurs. Before insertion, remove excess lubricating material to prevent excessive lubricating material from remaining and stagnating in the inlet pipe, thereby preventing fluctuations in the tension of the optical fiber. The long rate can be controlled within the target range, and a stable product can be manufactured.

When a gas or a filling substance is introduced into the metal tube through the introduction tube, a part of the gas or the filling material flows from the entrance of the introduction tube in a direction opposite to the traveling direction of the optical fiber and overflows, thereby causing the gas to flow out. The surface of the optical fiber can be wiped with a filler or a filling substance, and excess lubricating substance can be easily removed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the lubricant supply device of the embodiment.

FIG. 3 is a sectional view showing another lubricant supply device according to the embodiment.

FIG. 4 is a sectional view showing the optical fiber introduction device of the above embodiment.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

FIG. 6 is a sectional view showing a third embodiment of the present invention.

FIG. 7 is a sectional view showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view showing a fifth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal tube 2 optical fiber 3 first forming roll group 4 second forming roll group 5 optical fiber introduction device 55 introduction tube 7 lubricant supply device 72 container 73 removal device 76 lubricant 8 welding device

Claims (8)

(57) [Claims] 1. A metal tube-coated optical fiber cable for loading an optical fiber through an introduction tube inserted into said metal tube in a process of forming a metal strip into a tubular shape and then welding the butt portion to form a sealed metal tube. In the manufacturing method, an optical fiber or an optical fiber bundle having a lubricating substance attached to the introduction pipe was introduced, and the optical fiber or the optical fiber bundle was introduced.
Metal tube on the entrance side of the capstan where the metal tube is wound
Between the optical fiber and the optical fiber bundle.
Cap the tension between the metal tube and the optical fiber or optical fiber bundle.
Metal on the exit side of the capstan, reduced by the stun
Make the difference between the elongation of the tube and the optical fiber or optical fiber bundle
Controlling the extra length of the optical fiber or the optical fiber bundle by controlling the length of the optical fiber or the optical fiber bundle . 2. The outside diameter of the introduction pipe is larger than the inside diameter of the metal pipe.
2. The metal pipe according to claim 1, wherein said pipe is inserted into said metal pipe so as to keep the distance between said pipe and said metal pipe constant. A method for manufacturing a coated optical fiber cable. 3. The method according to claim 1, wherein the excess lubricating substance is removed before the optical fiber having the lubricating substance attached thereto is inserted into the introduction tube. 4. The method for producing a metal tube-coated optical fiber cable according to claim 1, wherein a gas or a filling substance is injected into the metal tube from the introduction tube. 5. A metal having means for forming a metal strip into a tube and welding the butt to form a sealed metal tube, and an inlet tube inserted into the sealed metal tube and guiding an optical fiber into the sealed metal tube. tube coated optical Faibake - in table production apparatus, e Bei a lubricant supply means for attaching the lubricant material to the optical fiber to be guided by the inlet tube, the optical fiber or
Capster around which a metal tube with an optical fiber bundle is wound
Tube and optical fiber or optical fiber bundle at the entry side
Between the metal tube and the optical fiber or optical fiber.
Reduce the tension of the fiber bundle with the capstan and
Metal tube and optical fiber or optical fiber at the exit side of the tongue
By providing a difference in the amount of elongation of the bundle,
An apparatus for manufacturing an optical fiber cable coated with a metal tube, characterized by controlling a surplus length of the fiber bundle . 6. An apparatus according to claim 5, further comprising an excess lubricant removing means for removing excess lubricant from the optical fiber passing through said lubricant supply means. 7. The apparatus according to claim 5, wherein a gas or a filling material is injected into the metal tube from the introduction tube. 8. The excess lubricant removing means is provided at an optical fiber inlet of the introduction pipe, and is configured to reverse a gas or a filling substance filled in the metal pipe in a direction opposite to a traveling direction of the optical fiber. An apparatus for manufacturing a metal tube-coated optical fiber cable according to claim 6 or 7.