JPH04324Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a heat-resistant optical fiber cable that can be used continuously at high temperatures of 300°C or higher.

An optical fiber storage groove is provided around the support, a colored tape is inserted into this groove to store the optical fiber, and a sheath is placed around the cable.
However, these devices are intended to be used at room temperature, and were designed with the idea in mind that both the support and sheath are made of plastic.

Furthermore, an optical fiber cable in which a hollow part for the optical fiber is carved in a spiral shape around a linear body at a predetermined pitch is known from Japanese Patent Application Laid-open No. 51-67141. Because the optical fiber is protected by a cable, it is difficult to apply direct force to the optical fiber when the cable is bent or pulled, so the fiber itself is less likely to be damaged, so it can be used as a heat-resistant cable. It's not something you get.

This invention was made in view of the above-mentioned circumstances, and will be explained below with reference to the drawings.

FIG. 1 shows that optical fiber storage grooves 2 consisting of U-grooves are provided at four locations around a steel wire member 1, an anticorrosive layer 5 is provided on the surface of the storage groove 2, and a metal-coated optical fiber 3 is stored in this. This is a heat-resistant optical fiber cable with an aluminum tube 4 coated on the outside.

FIG. 2 shows that the steel wire member 1 has optical fiber storage grooves 2 in the form of V-grooves at four locations around the periphery, and the steel wire member including these storage grooves is coated with an anti-corrosion layer 5 made of polyimide resin coating. A metal-coated optical fiber 3 is housed in the optical fiber housing groove 2, and the heat-resistant optical fiber cable is coated with an aluminum tube 4 on the outside.

FIG. 3 shows a cable having the cross-sectional structure shown in FIG. 1, in which the optical fiber storage grooves 2 are provided in a spiral shape at a constant pitch.

All of these cables use heat-resistant metal-coated optical fibers, which absorb stress into the storage groove 2 (with anti-corrosion layer 5) of the steel wire member 1, which has heat resistance and strength. Since the optical fiber is stored in an unprotected state, there is no mechanical influence on the optical fiber, and since the external aluminum tube 4 is also heat resistant, it is heat resistant as a whole.

A specific embodiment of the present invention will be described below regarding a cable manufactured according to FIG. 3.

An aluminum-coated fiber with an outer diameter of 125 μm and a core diameter of 50 μm is made into a spiral U-groove steel wire member (galvanized) with an outer diameter of 2.4 mm, and the U-groove has a width.
Put 4 pieces in a 0.3mm piece with a semicircular bottom and a spiral pitch of 200mm. A polyimide resin coating layer with a thickness of 20 μm is provided on the surface of the spiral steel wire.
The outside is coated with an aluminum tube with an inner diameter of 2.6 mmφ and an outer diameter of 4.0 mmφ.

For comparison, a cable was prototyped using a spiral U-grooved aluminum wire in place of the spiral U-grooved steel wire member. This and the above cable
When the cable was left in an atmosphere at 300°C for 60 hours, it was confirmed that the cable had 10 times the strength and lifespan of the comparison cable. In the present invention, a heat-resistant resin baking film is provided on the surface of the steel wire member as described above, or SiO ₂ , A ₂ O ₃ , ZrO ₂ ,
If an inorganic insulating film such as BO is applied by baking or plasma spraying, or if an oxide film is formed on the surface of the steel wire using an alloy material containing Si, A, etc., Even if moisture intrudes, there is no risk of electrolytic corrosion occurring between the steel wire and the aluminum tube.

Further, the optical fiber storage groove in the present invention may be linear or spiral, and the steel wire member storage groove may have a U-groove, V-groove, or any other structure that can accommodate the optical fiber. It can be of any shape. Furthermore, when the storage groove is spiral-shaped, the pitch of the spiral should be determined from a design perspective depending on the bending radius, etc., but is usually 50 mm to 800 mm.

[Brief explanation of drawings]

The figures show an example of the structure of the heat-resistant optical fiber cable of the present invention. Figure 1 is a sectional view of an example in which the storage groove is a U-groove, Figure 2 is a sectional view of an example in which the storage groove is a V-groove, and Figure 2 is a sectional view of an example in which the storage groove is a V-groove. FIG. 3 is a step-cut perspective view of an example in which the storage groove is spiral. 1... Steel wire, 2... Storage groove, 3... Metal coated optical fiber, 4... Aluminum tube, 5... Corrosion protection layer.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An anticorrosion coating is provided in an optical fiber storage groove provided around a steel wire member, a metal-coated optical fiber is stored in the storage groove, and an aluminum tube is coated on the outside. A heat-resistant optical fiber cable characterized by: (2) The heat-resistant optical fiber cable according to claim 1, wherein the optical fiber storage groove provided around the steel wire member is a V-groove or a U-groove.