JPS6051809A - Fire-proof optical fiber - Google Patents

Abstract

PURPOSE:To obtain a fire-proof optical cable which has superior fire-proof characteristics and is handled easily by storing an optical fiber core which has a protection coating in a metallic pipe which has through holes for emitting internal gas when heated. CONSTITUTION:The metallic tubular body 1 has plural through holes 10 for emitting internal gas in the pipe wall. Then, the optical fiber core 2 formed by covering an optical fiber 3 with a protection coating 4 made of glass fiber reinforced thermosetting resin is stored in the metallic tubular body 1, and a protection layer made of resin which does not impede the emission of the gas is preferably provided to the outer circumference of the metallic tubular body 1 to obtain the target fire-proof cable. Even when this fire-proof cable is heated at about 840 deg.C, the cracked gas, etc., in the metallic tubular body 1 are emitted out easily through the through holes 10, so the optical fiber 3 never break owing to an abnormal increase in the gas pressure in the metallic tubular body 1.

Description

[Detailed Description of the Invention] [Technical Field J] The present invention provides a method for preventing communication during heating even if the temperature is reduced to 8jO"C in 30 minutes in accordance with the fire temperature curve specified in JIS-A-1304. This relates to fire-resistant optical cables that can be secured.

(Prior Art) The present inventor conducted a fire resistance experiment on an optical couple in which a coated optical fiber 2 was housed in a metal layered body 1 as shown in FIG. A commonly used optical fiber 3 in which a protective coating 4 made of a thermoplastic resin such as nylon was provided around the outer periphery was used.

Like this 1. Partially the part where the f optical cable is about 84
When heated at 0°C, the protective seal 4 made of thermoplastic resin at the heated location 2j melted and formed a resin clump = I A, -j A, which blocked the inside of the metal tubular body i. . As a result, the gas pressure between the blocked parts increases, and in the worst case, the metal tubular body 1 ruptures, and in that case, the optical fiber 3
was sometimes broken. Furthermore, it was found that the transmission loss increased by about 1.02d13 130 minutes after heating started even though the optical fiber 3 did not break.

In addition to the above-mentioned optical cables, fire-resistant optical cables in which optical fibers are protected only by glass fibers and housed in metal pipes have recently been proposed, but such fire-resistant optical cables are difficult to handle when cutting or connecting. The drawback is that it is.

[Purpose of the invention]

In view of the above problems, it is an object of the present invention to provide a fire-resistant optical cable that has excellent fire resistance and is easy to handle.

[Structure of the invention]

In order to achieve the above object, the fireproof optical cable of the first aspect of the present invention includes a fiber core having a protective layer 0 and 11 through which internal gas can be released when heated. and a metal tubular body for accommodating the optical fiber.

The fire-resistant optical cable of the second invention has a fiber wire having a protective break and a penetration part capable of releasing internal gas when heated, and has an optical fiber core wire according to NFF. A protective layer is provided around the outer periphery of the metal tubular body and is made of a resin that does not inhibit the release of the gas.

1 Example of the invention] Examples of the present invention will be described in detail with reference to the drawings).

FIG. 2 is a multi-day drawing of an embodiment of the first invention of the present invention. As shown in FIG. 2, the fireproof light cape/L of the first invention is
A protective coating 4 made of glass fiber-reinforced thermosetting resin is attached to an optical fiber 3 inside a metal tubular body 1 having a plurality of through holes 10 for discharging internal gas IQ'r passing through the inner and outer surfaces of the tube wall.
The metal tubular body 1 has a plurality of j'J through holes 1 in advance.
It may be formed by forming a metal strip having an angle into a tubular shape and welding the seams, or it may not be welded. However, it is preferable to weld the metal tubular body 1 to the metal tubular body 1 (if construction strength is required).Also, it may be made by simply rolling the metal strip having the through hole 10 and overlapping the ends. .

In addition, if the joints of metal strips are not welded, or if the ends are simply overlapped, internal gas can be released to the outside from the joints or overlapped parts. Therefore, it is not necessary to provide the through hole 10 shown in FIG. Needless to say, in this case, the seams or bristles must not be glued together. Further, when the metal tubular body 1 is corrugated, its flexibility increases by -4, which is advantageous when wiring this fireproof optical cable or twisting a plurality of cables together to form a thick cable.

The one in Figure 2 accommodates only one optical fiber core 2, but even if there are multiple optical fibers, or if it is a composite assembly with a J or a metal conductor, - Yes.

3 and 4 show one embodiment of the second invention and other embodiments of the present invention. Figure 3: The first fire control light pull of the second invention is shown in Figure 3 (L'), which houses an assembly 5 of several FM optical fibers 2 inside. Through hole 1
The outer periphery of a metal tubular body 1 having a 0.0 temperature is coated with a protective layer 6 made of a resin that evaporates when exposed to high temperatures.

This protective layer 6 covers the cable partially 8, I o ”c
,: Vt2 When heated, it melts, vaporizes, etc. and escapes from the inside of the metal tubular body 1 through the through hole 10 to the outside, inhibiting the release of the gas. j(・
It is something. In addition, FIG. 4 shows a metal strip 1 without a through hole 10 as shown in FIG. 2 rolled up so as to have an overlapping portion 11.

In this case, since the metal strips are not bonded to each other in the overlapped portion 11, when the gas pressure inside the metal tubular body 1 decreases due to heating, the internal gas can also escape from the overlapped portion 11.

In addition, the protective cover of 9-Noaiba 3 is 4+, and the heat-resistant resin such as INOJ-Ron is 840 '' (IF heated, Multi: Generate IW gas for I knee.
The internal gas pressure of the shaped body 1 is easy to rise. Therefore, as explained in FIG.
1. Even under high temperatures, it has a great effect on all crops. The second protective coating 4 contains a large amount of glass fiber lamp 1, and has a relatively small amount of resin that generates decomposition gas. It is preferable because it is thin and requires less internal gas pressure. Also, as the material of the metal tubular body 10, iron-based materials such as stainless steel are preferable because they have excellent heat control properties.

In such a fireproof optical cable of the present invention, s4
Even if heated to 1" (:), the gases inside the metal tubular body, including the decomposed gas, are easily released to the outside through the 1"1 passage of the tubular body described in 1). The gas pressure of the optical fiber will not rise abnormally.Therefore, the metal tubular body will not rupture or the optical fiber will not break.Furthermore, according to the present invention, the increase in transmission loss of the optical fiber will be negligible. In addition, ((2) The optical fiber of the present invention using glass fiber as a protective coating is also shown in 7], -r) 1. In the case of using only glass fiber, l:I:
<J,') is hardened with thermosetting resin, so color 7,
It is easier to handle than one consisting of only one thin eyebrow.

Incidentally, the first invention of the present invention, which is a fire-resistant optical cable that does not have a protective coating on the outer periphery of the metal tubular body, is more likely to be used in combination with other power lines, etc., or by twisting a plurality of cables together. Furthermore, the second invention is suitable for a thick cable and a protective layer is provided on the outer periphery of the metal tubular body, and the second invention is suitable for use in cases where the protective layer is provided on the outer periphery of the metal tubular body. IC is suitable for use in many places, but is not limited to this usage.
I,-,.

1 Effect of the Invention 1 As stated above, the fire-resistant optical cable of the present invention has excellent heat resistance and is easy to handle during connection.

4 Detailed explanation of the present invention No. 11 No. 1 & j No. 4 sectional view showing the state when the conventional nine cables are applied or not, and Fig. 2 shows an embodiment of the first invention of the present invention. Figure 3 shows one embodiment of the second invention of the present invention, and Figure 41 shows another embodiment of the second invention. It is.

1 Metal tubular body, 2. Optical fiber core wire, 3.. fiber, 4. protective coating, 5. optical fiber wire, 6.
・Protective layer, I O-j! 4 holes, 11 overlapping parts.

Claims (5)

[Claims] (1) Consists of a cored optical fiber having a protective layer ω, and a metal tubular body that houses the cored optical fiber and has a penetration part that can release internal gas when heated. A fire-resistant optical cable characterized by: (2) The fire-resistant optical cable according to claim 1, wherein the penetration portion is a plurality of through holes passing through the inner and outer surfaces of the metal tubular body. (3) The fire-resistant optical cable according to claim 1, wherein the penetrating portion is a metal strip-shaped portion of the metal elongated body. (4) The fire-resistant optical cable according to claim 1, wherein the protective coating is made of a glass fiber-reinforced thermosetting resin. (5) An optical fiber core wire having a protective coating, a metal tubular body having a penetration part capable of releasing internal gas when heated and housing the optical fiber or wire, and the metal A fire-resistant optical cable characterized by comprising a protective layer formed on the outer circumference of the tubular body and made of a resin that does not inhibit the release of the gas.