JPH071607Y2 - Optical cable core structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a core structure of an optical cable, and more particularly to a core structure of a grooved spacer of a grooved spacer type optical cable.

[Conventional technology]

Conventionally, as a core structure of this type of optical fiber cable, there is an example of a core structure of a grooved spacer made of plastic having a tensile strength member made of FRP in the central portion and a plurality of grooves for accommodating the optical fibers on the outer periphery. .

[Problems to be solved by the device]

The core structure of the conventional grooved spacer is a structure in which the optical fiber is housed in the groove of the grooved spacer at the time of initial installation to form an optical cable. Therefore, if it is necessary to add an optical fiber at a later date after aerial wiring of the optical cable, it is not possible to insert the optical fiber into the groove of the grooved spacer using the existing optical cable, and another optical cable must be installed. It has to be laid, which is a problem in terms of construction work and economically.

The present invention solves the conventional problem, and when it is necessary to add the rear sunlight fiber, the core of the optical cable for inserting and storing the optical fiber for expansion is inserted by using the optical fiber installed in the initial optical fiber. It is intended to provide a structure.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a hollow portion at the center of a FRP strength member disposed in the center of a grooved spacer, and a plastic member is formed on the inner surface of the hollow FRP strength member having a hollow portion. It features a core structure with layers.

[Action]

The grooved spacer that forms the core of the optical cable of the present invention is
Since the structure has a hollow part with a plastic layer on the inner surface in the central part of the FRP tensile strength body placed in the central part, if an optical fiber for expansion is needed at a later date, a hollow part will be added. Using the existing optical cable core with FRP, it is possible to newly and easily insert an optical fiber having a required number of cores and a required length from the air pressure into the hollow portion of the FRP.

The FRP used as a tensile strength body has an appropriate repulsive force, does not bend extremely, and since the bending radius of the optical cable naturally increases, it is easy to insert the optical fiber.

In addition, FRP is a material with a high Young's modulus, and by applying FRP of an appropriate size according to the application, thermal contraction of the components of the optical cable such as plastics is suppressed, and it functions sufficiently as a strength member.

Furthermore, an FRP with a hollow part may be weakened in bending, but since it has a plastic layer on the inner surface of the FRP hollow part, it prevents the strength deterioration of the FRP itself and reduces the frictional force when inserting the optical fiber. Be peeled off. Embodiments will be described below with reference to the drawings.

〔Example〕

FIG. 1 is a view showing a cross-sectional structure of a core structure of an overhead optical cable according to an embodiment of the present invention. Reference numeral 1 is a grooved plastic spacer, 2 is a strength member made of FRP having a hollow portion 6 (hereinafter referred to as FRP), 3 is a plastic layer applied to the inner surface of the hollow portion 6 of FRP 2, and 4 is a plastic grooved in advance during initial installation. The optical fibers 5 arranged and housed in the groove of the spacer 1 are optical fibers inserted and housed in the hollow portion 6 for expansion if necessary.

In FIG. 1, the grooved plastic spacer 1 is a commonly used U-shaped or square grooved grooved plastic spacer. Initially, the required number of optical fibers 4 are stored based on the design at the time of installation. The plastic material is used and polyethylene is usually used.

The FRP of the tensile strength member 2 is provided with a hollow portion 6 into which the rear sunlight fiber 5 is inserted and which is additionally installed. As the FRP material, an inexpensive and commonly used material is applied. Also, considering the function as a strength member, the diameter should be as small as possible.

The plastic layer 3 is provided on the inner surface of the FRP 2, and it is desirable to use an inexpensive material such as polyethylene having a small coefficient of friction with the optical fiber 5 to be inserted, and to make it the minimum necessary thickness.

The number of optical fibers 5 to be inserted in the hollow portion 6 is set in advance, and the hollow portion 6 has a minimum diameter dimension corresponding to the preset number, and the outer diameter of the cable is made as small as possible.

The FRP2 having the hollow portion 6 can be easily manufactured by using a plastic molding machine, and the plastic layer 3 can be manufactured by simultaneously performing two-layer extrusion processing at the time of manufacturing the FRP2.

The grooved plastic spacer 1 is a FRP2 having a hollow portion 6.
The plastic core can be easily manufactured by processing the plastics on the outer peripheral surface of the plastics using a plastic molding machine to form the cable core.

Further, the grooved plastic spacer 1, FRP 2, and plastic layer 3 can be simultaneously processed, and the simultaneous processing method is economical in terms of price.

Grooved plastic spacer 1 for manufactured cable core
After the optical fiber 4 is housed in the groove portion of the device using a collecting machine, a desired winding is formed and a covering is applied to form a desired optical cable.

The optical cable with the above core structure will be laid according to the plan. However, when it is necessary to add more optical fibers at a later date, the hollow portion of the grooved plastic spacer 1 of the optical cable in which the optical fibers 5 have already been laid. Apply the air pressure method in 6 and insert the required number and length, and add the optical fiber using the existing optical cable.

[Effect of device]

As explained above, the core of the optical cable according to the present invention has a hollow portion with a plastic layer on the inner surface in the central portion of the FRP tensile strength member of the grooved plastic spacer. When an optical cable is laid and it is necessary to add a rear Nikko fiber,
By inserting the required number of optical fibers into the hollow part provided in the center of the FRP of the tensile strength body of the grooved plastic spacers for the required length, it is possible to add optical fibers using the existing optical cables and save time. It is possible to increase the number of optical fibers by hand, equipment, and rationalize the construction.
It is extremely effective for workability and economy when applied to the core structure of optical cables in the construction of optical cable networks expected to be expanded.

[Brief description of drawings]

FIG. 1 is a sectional view of the core of an optical cable embodiment of the present invention. 1 ... Groove plastic spacer with groove, 2 ... Tensile member (FR
P), 3 ... plastic layer, 4 ... optical fiber (initial),
5 ... Optical fiber (expansion), 6 ... Hollow part

Claims (1)

[Scope of utility model registration request] 1. A hollow of a strength member (2) made of FRP having a hollow portion (6) in the center of a strength member (2) made of FRP arranged in the center of a grooved spacer. A core structure of an optical cable comprising a structure having a plastic layer (3) on the inner surface of the section.