KR20110061268A - The flat type drop cable - Google Patents

Abstract

PURPOSE: A flat type drop cable is provided to prevent the escape of a first tensile strength body due to the self-load of the cable and increase the bonding force of the first tensile strength body by coating an adhesive reinforcing material on the external surface of the first tensile strength body. CONSTITUTION: A pair of first tensile strength bodies(20) is parallelly arranged on the upper side and the lower side of optical fiber(10) along the longitudinal direction of the optical fiber. A first sheath part(30) covers the optical fiber and the first tensile strength bodies. A second tensile strength body(40) is arranged on the upper side of the first sheath part. A second sheath part(50) covers the second tensile strength body.

Description

Flat Drop Cables {THE FLAT TYPE DROP CABLE}

The present invention relates to a flat drop cable including a pair of first tensioning body and one second tensioning body, and more particularly, to improve the bonding force of the first tensioning body and the sheath for preventing deformation of the optical fiber. It relates to a flat drop cable.

In general, an optical cable is composed of an optical fiber unit for transmitting an optical signal and a sheath for protecting the optical fiber unit.

Here, the sheath for protecting the optical fiber unit has a structure in which an anti-tension body such as steel wire or glass fiber reinforced plastic is inserted to withstand the tensile force applied in the process of laying the optical cable.

In addition, in the case of the drop cable for FTTH for connecting the optical cable to the premises via the telephone pole, the optical fiber unit and the support line part surrounding the support line with the sheath material are separated into a flat structure. It is.

Here, in order to implement the FTTH network, when a cable is connected to the house via a telephone pole, a cable is installed between the telephone pole and the telephone pole, and tension is generated in the cable by gravity, which causes stress to the optical fiber unit, thereby causing breakage. have.

Therefore, in the general flat drop cable, the first tensioning body 20 and the support line 40 of the support line part serve to protect the stress that the optical fiber unit 10 may receive from the tensile force generated.

However, when the flat drop cable is installed, as shown in FIG. 1, when the cable 100 stretches downward due to the load of the cable 100 itself, tension is generated in the cable, which is located under the optical fiber unit 10. The first tensioning body 20 is relatively longer than the support line 40 on the upper side.

Here, the tensile restoring force is generated in the lower first tensioning body 20 which is relatively increased, thereby affecting the bonding force between the sheath 30 and the first tensioning body 20.

Subsequently, when the tensile restoring force of the increased first tensioning body 20 is greater than the bonding force between the sheath 30 and the first tensioning body 20, the two materials are separated, so that the first tensioning body 20 is larger than the sheath 30. Will be shortened.

As a result, the detached first tensioning body 20 does not function properly as a tensioning body, and as time passes, the optical fiber unit 10 is stressed to increase optical signal loss due to breakage of the optical fiber unit 10. Cause.

The present invention has been made to solve the above problems, an object of the present invention, the tensile restoring force caused by the sagging of the first tension member that may occur when the flat drop cable is installed between the sheath portion and the first tension member. To provide a flat drop cable configured so as not to affect the bonding force of the.

Still another object of the present invention is to provide a flat drop cable in which an adhesive reinforcing member is coated on an outer surface of the first tensioning body to increase the bonding force between the sheath portion and the first tensioning body.

Still another object of the present invention is to provide a flat drop cable in which a notch portion is formed in the sheath portion to facilitate exposure of the optical fiber when the cable is connected and connected.

의 관계를 만족하는 플랫형 드롭 케이블에 의해 달성될 수 있다.(F : 제 1 항장력체와 제 1 시스부의 접합력,

: 제 1 항장력체의 탄성 계수,

: 전주 사이의 거리가 100m 인 경우, 케이블의 자중에 의해 늘어난 제 1 항장력체의 길이)The object is, according to the present invention, an optical fiber unit; A pair of first tensioning bodies disposed above and below the optical fiber unit in parallel along the longitudinal direction of the optical fiber unit; A first sheath portion covering the optical fiber unit and the first tension member; A second tensioning body disposed above the first sheath portion; A second sheath portion covering the second tension force;

Can be achieved by a flat drop cable that satisfies the relationship of (F:

Is the elastic modulus of the first tension body,

: Length of the first tensioning body increased by the weight of the cable when the distance between poles is 100m)

Here, the bonding force F of the first tensioning body and the first sheath portion may be provided to be smaller than the breaking strength of the first tensioning body.

In addition, the outer surface of the first tension member may be coated with an adhesive reinforcing member for increasing the bonding force with the first sheath portion.

Here, the adhesion reinforcing member may be provided with ethylene acetic acid or ethylene acrylic acid.

In addition, the optical fiber unit may be provided as a single-core optical fiber, a multi-core optical fiber or a ribbon type optical fiber.

On the other hand, the first tension member may be made of fiber glass reinforced plastic (Fiber glass reinforced plastic).

In addition, the first sheath portion may further include notches formed on both sides along the length direction of the first sheath portion.

In this case, the second tension member may be provided as a steel wire or a steel wire.

In addition, the first sheath portion and the second sheath portion may be integrally provided.

Here, the first sheath portion and the second sheath portion may be made of polyethylene (PE) or low smoke zero halogen (LSZH).

According to the present invention, the tensile restoring force due to the sagging of the first tensioning body does not affect the bonding force between the sheath portion and the first tensioning body, so that the dropping of the first tensioning body due to the weight of the cable can be prevented.

In addition, by bonding an adhesive reinforcing member on the outer surface of the first tension member, the bonding force between the sheath portion and the first tension member can be increased.

In addition, by forming a notch in the sheath portion, when the cable is connected and connected, easy exposure of the optical fiber can be realized.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

Prior to this, terms used in the present specification and claims should not be construed in a dictionary meaning, and the inventors may properly define the concept of terms in order to explain their invention in the best way. It should be construed as meaning and concept consistent with the technical spirit of the present invention.

Therefore, the embodiments shown in the present specification and the drawings are only exemplary embodiments of the present invention, and not all of the technical ideas of the present invention are presented. Therefore, various equivalents It should be understood that water and variations may exist.

1 is a model of a flat drop cable stretched between the poles, Figure 2 is a modeling graph of the flat drop cable according to the invention, Figure 3 is a perspective view of a flat drop cable according to the invention, Figure 4 Is a perspective view of a flat drop cable according to another embodiment of the present invention.

1 to 4, the flat drop cable 100 according to the present invention, the optical fiber 10; A pair of first tensioning bodies (20) disposed above and below the optical fiber (10) in parallel along the longitudinal direction of the optical fiber (10); A first sheath portion 30 covering the optical fiber 10 and the first tensioning body 20; A second tension body (40) disposed above the first sheath portion (30); And a second sheath portion 50 covering the second tension body 40.

의 관계를 만족한다.(F : 제 1 항장력체와 제 1 시스부의 접합력,

: 제 1 항장력체의 탄성계수,

: 전주 사이의 거리가 100m 인 경우, 케이블의 자중에 의해 늘어난 제 1 항장력체의 길이)F>

(F: the bonding force of the first tension body and the first sheath portion,

= Modulus of elasticity of the first tension body,

: Length of the first tensioning body increased by the weight of the cable when the distance between poles is 100m)

Here, the optical fiber unit 10 is composed of a unit aggregate containing one or more optical fiber core wires.

Here, the optical fiber core wire is a portion in which an optical signal including data is transmitted, and in general, glass fiber made of silica material having a high refractive index is used for the core part, and glass or synthetic resin made of silica material having a low refractive index is used for the clad part. Implement the role of transmitting the optical signal passing through the center by total reflection.

Preferably, the optical fiber core wire may be formed by coating with a polymer resin on the outer surface of the core wire to mechanically protect the core and the cladding.

The optical fiber unit 10 may be configured as a loose cable type in which the one or more optical fiber core wires are arranged at predetermined intervals, or a ribbon cable formed by closely contacting one or more optical fiber core wires in a ribbon form. It may be configured as a cable type.

That is, the optical fiber unit 10 may be provided as a single-core optical fiber, a multi-core optical fiber or a ribbon type optical fiber.

In addition, the first tension member 20 is disposed on the upper and lower portions of the optical fiber unit 10 to generate the tensile force to protect the optical fiber unit 10 when a deformation such as bending the optical cable 100 is applied. As an element to be able to, it also performs the function of forming the center skeleton of the cable.

In this case, the first tension member 20 is a stiff, yet somewhat elastic material Kevlar aramid yarn (Kevlar aramid yarn), an epoxy fiber rod (Fiber glass epoxy rod), glass fiber reinforced plastic (Fiber glass reinforced plastic ) But may not be limited thereto.

The optical fiber unit 10 and the first tensioning body 20 are surrounded by the first sheath portion 30, as shown in FIGS. 3 to 4.

Here, the first sheath portion 30 forms the outer shape of the cable, and serves as a mechanical protection function, polyethylene, low smoke zero halogen (LSZH), PVC, or olefin (Olefin) It is composed of an insulating material such as a) -based polymer material, but can be variously modified within the scope of the known technical idea depending on the purpose of use and the installation environment.

In addition, a glass fiber layer may be disposed inside the first sheath portion 30 to improve the strength of the cable and improve the bending property of the cable.

Alternatively, a metal jacket may be further configured inside the first sheath portion 30 to block alien crosstalk caused by electromagnetic waves generated from other adjacent cables or other electronic equipment.

In addition, the first sheath portion 30 may further include a notch portion 32 formed at both sides along the longitudinal direction of the first sheath portion 30.

Here, the notch part 32 easily peels off the first sheath part 30 when the first sheath part 30 is exposed to expose the optical fiber unit 10 when the optical cable 100 is connected or connected. It is a component for.

On the other hand, the second tension member 40 is disposed above the first sheath portion 30 covering the optical fiber unit 10 and the pair of first tension member 20 to increase the tension of the cable 100. It is a component that reinforces.

Preferably, the second anti-tensile body 40 may be provided as a steel wire or a stranded wire, Kevlar aramid yarn (Kevlar aramid yarn), fiber glass epoxy rod (Fiber glass epoxy rod), Fiber glass reinforced plastic may be provided, but is not limited thereto.

3 to 4, the second tension member 40 is coated by the second sheath portion 50, and the first sheath portion 30 and the second sheath portion 50 are coated with the second sheath portion 50. It can be provided integrally.

Here, the second sheath portion 50 is formed integrally with the first sheath portion 30, it may be formed continuously or intermittently along the longitudinal direction of the optical cable 100.

In addition, the second sheath portion 50 may be made of polyethylene (PE) or low smoke zero halogen (LSZH), PVC, or olefin (Olefin), like the first sheath portion 30 described above. It may be composed of an insulating material such as a polymer material.

The flat drop cable provided as a component as described above has a tensile restoring force between the first sheath portion 30 and the first tensioning body 20 due to the stretching of the first tensioning body 20 that may occur when the cable is installed. It provides a structure that does not affect the bonding force of the.

To explain this in more detail, the cable installed between the two poles is modeled with the equation of a suspension line (curved rope between them when both ends of a uniform rope are fixed at two positions of the same height) as shown in the graph of FIG. It is expressed as the formula below.

(H: horizontal tension of cable, w: weight of cable per unit length)

는 아래의 식으로 정리된 다.Further, the second sheath portion 50 and the first sheath portion 50 and the second sheath portion 50, which cover the second tensile force body 40 modeled by the suspension equation, can be formed at any point. 1 difference in the length of the extension of the tension body 20

Is summarized by the following equation.

Here, p is the distance between the second sheath portion 50 and the first tensioning body 20, H is the horizontal tension of the cable, w is the weight per unit length of the cable, the first tension by using the above formula The tensile restoring force due to the elongated length of the sieve 20 is summarized as follows.

Here, k means the elastic modulus of the first tension body material.

By using the above formula, by forming the bonding force of the first tensioning body 20 and the first sheath portion 30 equal to or greater than the tensile restoring force of the first tensioning body 20, the tension of the first tensioning body 20 It is possible to prevent the separation of the first sheath portion 30 and the first tension member 20 that may be generated by the restoring force, thereby preventing the stress received by the optical fiber unit 10.

That is, the cable is manufactured in consideration of the influence of the tensile restoring force of the first tensioning body 20 that can be generated when the cable is installed, whereby the bonding force between the first tensioning body 20 and the first sheath portion 30 is the first. It is possible to design a cable that is equal to or greater than the tensile restoring force of the tensioning body 20.

Here, after the adhesive reinforcing member 22 is coated on the outer surface of the first tension member 20 to increase the bonding force between the first tension member 20 and the first sheath portion 30, the first sheath portion 30 may be combined.

Preferably, the adhesion reinforcing member 22 may be made of ethylene acetic acid or ethylene acrylic acid, and may be coated on the outer surface of the first anti-tension body 20, but is not limited thereto. Of course, it may be coated as.

On the other hand, the bonding force F of the first tensioning body 20 and the first sheath portion 30 may be provided to be equal to or less than the breaking strength of the first tensioning body 20 itself.

That is, the bonding force between the first tensioning body 20 and the first sheath portion 30 is equal to or greater than the tensile restoring force according to the increased length of the first tensioning body 20 and the first tensioning body 20 itself. By constructing less than or equal to the breaking strength, the separation of the first tensioning body 20 and the first sheath portion 30 due to the weight of the cable can be prevented.

Therefore, the flat drop cable 100 according to the present invention can prevent the first tensioning body 20 and the first sheath portion 30 from falling off to protect the optical fiber unit 10 from the stress caused by the cable weight. The optical signal loss rate can be reduced.

As described above, in the flat drop cable according to the present invention, the tensile restoring force due to the sagging of the first tensioning body does not affect the bonding force between the sheath portion and the first tensioning body, so that Falling can be prevented, and the bonding strength of the sheath portion and the first tension member can be increased by coating an adhesive reinforcing member on the outer surface of the first tension member, and when the cable is connected and connected by forming a notch in the sheath, Easy exposure can be achieved.

As mentioned above, although the present invention has been described by way of limited embodiments and drawings, the technical idea of the present invention is not limited thereto, and a person having ordinary skill in the art to which the present invention pertains, Various modifications and variations may be made without departing from the scope of the appended claims.

Since the accompanying drawings are for understanding the technical spirit of the present invention together with the detailed description of the above-described invention, the present invention should not be construed as limited to the matters shown in the following drawings.

1 is a model diagram of a flat drop cable is installed between the poles,

2 is a modeling graph of a flat drop cable according to the present invention,

3 is a perspective view of a flat drop cable according to the present invention,

4 is a perspective view of a flat drop cable according to another embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: optical fiber unit 20: first tension body

22: adhesive reinforcing member 30: first sheath portion

32: notch 40: second tensile force body

50: second sheath 100: flat drop cable

Claims (10)

An optical fiber unit; A pair of first tensioning bodies disposed above and below the optical fiber unit in parallel along the longitudinal direction of the optical fiber unit; A first sheath portion covering the optical fiber unit and the first tension member; A second tensioning body disposed above the first sheath portion; And a second sheath portion covering the second tension member; F>

Flat drop cable, characterized in that to satisfy the relationship. (F: bonding force between the first tensioning body and the first sheath portion,

= Modulus of elasticity of the first tension body,

: Length of the first tensioning body increased by the weight of the cable when the distance between poles is 100m) The method of claim 1, The joining force F of the first tensioning body and the first sheath portion is smaller than the breaking strength of the first tensioning body. The method of claim 1, Flat outer drop cable characterized in that the outer surface of the first tension member is coated with an adhesive reinforcing member for increasing the bonding force with the first sheath portion. The method of claim 3, wherein The adhesive reinforcing member is a flat drop cable, characterized in that provided with ethylene acetic acid or ethylene acrylic acid. The method of claim 1, The optical fiber unit is a flat drop cable, characterized in that provided by a single-fiber optical fiber or multi-core optical fiber or ribbon type optical fiber. The method of claim 1, The first tension member is a flat drop cable, characterized in that provided with fiber glass reinforced plastic (Fiber glass reinforced plastic). The method of claim 1, And said first sheath portion further comprises notches formed on both sides along the longitudinal direction of the first sheath portion. The method of claim 1, The second tension member is a flat drop cable, characterized in that provided with a steel wire (line) or strand. The method of claim 1, And the first sheath portion and the second sheath portion are integrally provided. The method of claim 9, The first sheath portion and the second sheath portion is a flat drop cable, characterized in that the polyethylene (PE) or low smoke zero halogen (LSZH) is provided.

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