JPS58185457A - Metal coater for optical fiber - Google Patents

Abstract

PURPOSE:The titled coater in which a pipe for guiding the optical fiber is provided so that it connects to the opening of the upper-side through-hole on the outer wall and the lower-side through hole is tapered on the inside wall opening, thus showing good operability and centering between the through-hole and the optical fiber. CONSTITUTION:The crucible 5 containing the melted metal for coating the optical fiber 4 such as Al, Sn, or In is provided with the guide pipe 6 projected horizontally at the bottom and through-holes 16, 17 are bored at both top and bottom of the pipe wall for passing through the optical fiber 4. Further, a guide pipe 11 is furnished on the hole 16 extending upward so that the operability is increased in the introduction of the optical fiber. The through-hole 17 on the bottom is tapered so that the inlet of the optical fiber 4 is more opened to prevent the metal melt to flowing out. The optical fiber 4 is passed through the hole 14 on the cover 13, further the through-holes 16 and 17 and the optical fiber coated with metal is taken out of the hole 15 in high operability. This process, moreover, facilitates centering between the through-holes 16 and 17 and the optical fiber 4 to give high-quality optical fiber coated with metal.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical distribution of the invention The present invention relates to a metal coating apparatus for continuously and uniformly coating a long optical fiber with metal, and particularly to the structure of a melting crucible.

(bl Background of the technology) After drawing and spinning, optical fibers made of glass materials used as optical transmission paths are used to prevent scratches on the surface of the fibers, and to obtain high-quality optical fibers immediately after spinning. Resin coating is applied to the optical fiber of °C?
a! 1iIII protection is carried out. In such resin-coated optical fibers, moisture passes through the resin and enters the surface of the glass fiber.In recent years, metal coatings have been used instead of resin. I'm on top.

(U) Conventional technology and problems Figure 1 shows a diagram of an optical fiber using a conventional metal melting crucible.
It is a figure explaining m process.

Molding L by the well-known vapor phase one-height horizontal method (EVU method), etc.
The optical fiber base material 1 is heated in a heating furnace 2,
A metal such as aluminum (AJ), tin (8 ports), zinc (Zo), or indium (In) is coated on the extraction path of the optical fiber 4, which is stretched into a small diameter optical fiber and delivered to the drum 8. A heated and melted crucible 6 is disposed, and a molten metal outlet pipe 6 protrudes from the bottom of the crucible 5.
The optical fiber 4 was coated with molten metal 9 through holes 7 and 8 provided in the wall thereof and passing through the optical fiber. Note 10
indicates a heating furnace.

The through holes 7 and 8 provided in the molten metal outlet pipe 6 of the crucible 5 used for such metal coating are 0 and 81 fIN for the outer diameter of the optical fiber wire of 100 to 200 μ#IO.
It has pores with a size of about 0.0 or less. If the hole is made larger than this, the molten metal 9 will come out, so it is preferable to make the hole as small as possible.

In order to coat the optical fiber with metal, it is necessary to quickly insert the optical fiber through the through hole 7 when starting the process of passing the optical fiber through the through hole, or when restarting the work when the optical fiber is broken. It was difficult to pass through 8 and the workability was very poor.

(d) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a method for spinning an optical fiber,
Immediately after that, when starting the work of metal coating the optical fiber, it is easy to pass the optical fiber through the optical fiber straight hole provided in the molten metal lead-out tube, and the optical fiber passing through the straight hole is The object of the present invention is to provide a metal-coated Wf device for optical fibers that is also excellent in centering.

According to the present invention, the purpose of this invention is to provide a crucible for melting a metal to be MW-grown into an optical fiber with a molten metal outlet tube that protrudes laterally, and to In a crucible lζ having a through hole through which an optical fiber is inserted at a corresponding position, a vibrator is provided that communicates with the open end of the upper through hole on the outer wall side and guides the optical fiber to be introduced. This is achieved by tapering the open end of the inner wall to facilitate insertion of the optical fiber.

(g) Embodiments of the Invention Examples of the present invention will be described in detail with reference to the drawings. Second
The figure shows the metal coating for optical fibers according to the present invention! ! 1 is a diagram showing the structure of an apparatus, in particular a gold tI4 melting crucible; FIG.

In the figure, the same reference numerals as in FIG. 1 indicate the same functional parts.

The structure of the crucible of the present invention is such that a molten metal outlet tube 6 is provided at the lower end of the crucible 5 for melting metal, and which protrudes laterally, and optical fibers 4 are connected above and below the #i wall of the molten metal outlet tube 6.
Holes 16 and 17 are provided to pass through the upper through hole 16.
is a large hole with an inner diameter of 2 to 8 mm, and a pipe for guiding an upwardly extending optical fiber or a guide means having a guide hole for achieving a similar purpose is installed in the chain hole 16, and the optical fiber 4 is introduced. The structure is such that the workability when doing so can be the same as above. Further, the through hole 17 on the F side has a tapered shape that is open on the inlet side of the optical fiber 4, and the opening diameter of the taper is set to be about the same as the inner diameter of the optical fiber guide pipe 11, for example, 2 to 9 mm. In addition, the diameter of the other tapered hole on the exit side of the optical fiber is configured to be equal to or larger than α8# drop to prevent the molten metal from flowing out. The material of this crucible 5 is stainless steel, alumina (A-LOs), etc.
It may be made of a material that can withstand heat. Further, the height of the guide pipe 11 attached to the crucible may be configured to be higher than the liquid level of the molten metal 9, but if the tension of the molten metal is large, Iζ1. In some cases, a lower lf position may be sufficient. In addition, the metal AM device for optical fiber prevents oxidation of the molten metal 9.
Cover the outer periphery of the crucible 5 with a transparent insulator such as quartz 18
Surrounding the metal (2), oxidation of the molten metal is prevented by flowing a wood gas or the like from the inlet 18 of the cover 18.

The metal used to cover the optical fiber 4 is aluminum (
AJ), tin (80), zinc (Zn), indium (1
++) It is possible to use similar metals.

Holes 14 and 15 are formed in the cover 13 to allow the optical fiber 4 to pass through, and the chain holes 14 and 15 also serve as an outlet for the nitrogen N that has entered from the inlet 18.

- The blade-side thermal furnace 10 is provided on the outer periphery of the cover 18 and melts the metal in the crucible 5 using an electric furnace or the like.

If the optical fiber metal coating apparatus having the configuration 1(1) is used, the optical fiber 4 can be coated with the metal through the hole 14 of the cover 18 when the optical fiber 4 is coated with metal online immediately after spinning.
through the through-holes 16 and 17 (the optical fiber that has completed metal coating can be taken out from the hole 15 with good workability. Furthermore, it is also possible to center the through-holes 16 and 17 with the optical fiber 4 passing through it. This makes it easy to obtain high-quality metal-coated optical fibers.

(g) Effects of the invention As explained in detail above, when manufacturing metal-coated optical fibers, the use of the metal-coating device for optical fibers of the present invention improves workability and improves the connection between the straight hole and the optical fiber. Excellent centering and stable metal-coated optical fiber can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a method for manufacturing a gold coated optical fiber using a conventional metal melting crucible, and FIGS. 1 binary fiber base material, 2: heating furnace, 8 Ni drum 4: optical fiber, 5 Nil crucible, 6: #ll gold metal outlet tubes 7 and 8: through hole, 9: jll gold metal lO: heating furnace, 1: $
Inner high, 18: force i<-114 and 15: hole, 16
and 17: through hole, 18 two populations. @I ・1 ・possible l2nf( □--j 16

Claims (1)

[Claims] A crucible that holds a metal to be coated on an optical fiber is provided with a molten metal lead-out pipe that protrudes laterally, and a through hole through which the optical fiber is inserted is provided at vertically corresponding positions on the tube wall of the molten metal lead-out pipe, A pipe is provided that communicates with the open end on the outer wall side of the L up-side through hole to guide the optical fiber to be introduced, and the open end on the inner wall side of the D side through hole is opened in a tapered shape to facilitate insertion of the optical fiber. A metal coating device for optical fibers characterized by a tightening mechanism.