JPH1123927A - Manufacture of optical fiber with hanging wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost, to shorten the days required for manufacturing and to improve workability at a cable extending work by collectively pushing out a sheath while respectively controlling send-in speeds of hanging wire and optical fiber cable core sent into an extruding equipment. SOLUTION: The hanging wire 5 constituted of twisting plural pieces of element wires of a galvanized steel wire is sent out from a send-out drum 4 for hanging wire. The optical fiber cable core 7 integrating a single fiber or plural optical fiber core wires is sent out from the send-out drum 6 for the optical fiber cable core. Respective wire and core are sent out by a belt lap capstan 8. The hanging wire 5 and the core 7 are performed collectively with the sheath of a gourd-shaped sectional shape by the extruding equipment 9. At this time, the send-in speeds of the hanging wire 5 and core 7 sent into the extruding equipment 9 are made respectively V2, V1. The sheath is pushed out collectively while respective send-into speeds are controlled so as to become V2<V1<=1.005.V2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable, and more particularly to an optical fiber cable with a surplus length in which a gourd-shaped sheath having a cross-sectional shape is collectively provided on the outer periphery of a suspension wire and an optical fiber cable core to give an extra length to the optical fiber cable. The present invention relates to a method for manufacturing a cable.

[0002]

2. Description of the Related Art An optical fiber cable with a suspension wire is generally said to extend by about 0.2% when a tension is applied to the suspension cable when the cable is extended or tightened, or when a natural phenomenon such as wind pressure is applied to the suspension cable. I have. In this case, if the length of the suspension wire and the length of the optical fiber cable are the same, the optical fiber cable also becomes 0.2%
The optical fiber in the cable is also extended by about 0.2%. As a result, the transmission loss of the optical fiber may increase, causing a communication problem.

[0003] Therefore, it has been developed that the optical fiber cable is not expanded even if the suspension wire is expanded, as shown in FIG.
The extra-length optical fiber cable with a suspension line, such as the pre-hanger type optical fiber cable shown in FIG. 4A is a sectional view, and FIG. 4B is a side view. This pre-hanger type optical fiber cable is composed of a coated suspension line 1, an optical fiber cable 2, and a support 3 for supporting and fixing the optical fiber cable 2 at a predetermined pitch. About 0.2%.

[0004]

However, the above-mentioned optical fiber cable has the following problems.

[0005] (1) Coating extrusion process of a suspension wire which is coated with a suspension wire to make a coating suspension line 1, coating and extrusion process of an optical fiber cable core which is a coating of an optical fiber cable core and an optical fiber cable 2, and further a coating suspension wire. 1 and the optical fiber cable 2 are molded and fixed at a predetermined pitch, and three molding steps are required, which requires a large number of manufacturing days and increases costs.

(2) Since the support 3 is manufactured by molding, the working speed is slow, which causes high cost and long manufacturing days.

[0007] (3) When the extra length of the optical fiber cable with a hanging wire is extended, the projections of the support 3 are often caught by a guide such as a wheel and the workability is poor.

Accordingly, the present invention has been conceived to solve the above-mentioned problems of the prior art, and has been developed to provide a low-cost, short-manufacturing, and high-workability optical fiber cable with a suspension cable. It is to provide a manufacturing method.

[0009]

According to the present invention, in order to achieve the above-mentioned object, a suspension wire and an optical fiber cable core are arranged in parallel and fed out, and a sheath having a gourd-shaped cross section is extruded around the outer periphery of the cable by an extruder. In the manufacturing method of the optical fiber cable with a suspension wire which is extrusion-coated in a lump, assuming that the feeding speeds of the suspension wire and the optical fiber cable core fed into the extruder are V2 and V1, respectively, V2 <V1 ≦ 1.
Provided is a method for manufacturing an optical fiber cable with a suspension line, characterized in that the sheath is extruded at a time while controlling the respective feeding speeds so as to obtain 005 · V2.

Further, in order to achieve the above object, the present invention is characterized in that when a suspension wire and an optical fiber cable core are extruded at once, a slit is intermittently formed in a gourd-shaped cross-section neck. And a method for manufacturing an optical fiber cable with a suspension wire.

[0011]

Embodiments of the present invention will be described below.

FIG. 1 is a schematic view of an optical fiber cable with a suspension wire according to the present invention.

A plurality of (for example, seven) strands of galvanized steel wire are twisted from the delivery drum 4 for the suspension wire, and a single wire or a plurality of wires are delivered from the delivery drum 6 for the optical fiber cable core. The optical fiber cable cores 7 in which the optical fiber core wires are assembled are fed out and sent out by a feed belt wrap capstan 8 respectively.

FIG. 2 is a sectional view of the feed belt wrap capstan 8. As shown in FIG.

D1 is the outer diameter of the optical fiber cable core, d2
Is the outer diameter of the suspension wire, D1 is the diameter of the capstan on the optical fiber cable core, and D2 is the diameter of the capstan on the suspension line. In general, d1> d2 and D1> D2 are established. I have.

These capstan diameters D1 and D2 are:
The following relational expression is designed to hold. Note that λ
Is the extra length ratio of the cable to be obtained, V1 is the sending speed of the optical fiber cable core 7, and V2 is the sending speed of the suspension line 5.

Λ = V1 / V2 = (D1 + d1) / (D2 + d2) (2) According to the equation (1), V1> V2 is satisfied for V1 and V2. Since (3) is satisfied, λ> 1 is also satisfied.

The feed belt wrap capstan 8 is
The capstan on the suspension line side and the capstan on the optical fiber cable core side are made of a single body. The suspension line 5 and the optical fiber cable core 7 can be sent to these capstans from the outside of the capstan so that they can be brought into close contact with each other. The structure is such that the suspension wire 5 and the optical fiber cable core 7 are pressed against the capstan by a leather belt.

As a result, the ratio of the feed speed V1 of the optical fiber cable core to the feed speed V2 of the suspension wire is (D1 + d1) and (D1
2 + d2), which gives the extra length λ. However, when the excess length ratio λ exceeds 0.5%, that is, V1> 1.005 · V2 (5), the optical fiber cable core 7 and the suspension line 5 are collectively placed. When the sheath is applied to the optical fiber cable, failures such as uneven thickness of the sheath on the optical fiber cable core side frequently occur. Therefore, the excess length ratio λ is preferably set to 1 <λ ≦ 1.005 (6).

Thereafter, the suspension wire 5 and the optical fiber cable core 7 are collectively sheathed by the extruder 9. At this time,
The slit forming device 10 provided at the outlet of the extruder 9 makes it possible to form a slit hole in the gourd-shaped cross-section neck. The sheathed optical fiber cable with a suspension wire is then cooled by passing through a cooling water tank 11, taken up by a take-up machine 12, and wound up on a drum by a take-up machine 13.

FIGS. 3A and 3B show the optical fiber cable with a suspension line manufactured as described above, wherein FIG.
(B) is a side view, (c) is a top view, 20 is a sheath neck, and 21 is a slit provided in the sheath neck. The dimensions of the neck portion of the gourd-shaped sheath in cross section are preferably 0.5 to 10 mm in thickness and 0.5 to 30 mm in height. When slits are provided, the height of the neck portion is preferably 20 mm or more and the slit length is preferably 1 m or less. As can be seen from a comparison between the optical fiber cable with a suspension cable obtained by the method of the present invention shown in FIG. 3 and the conventional product of FIG. 4, the optical fiber cable with a suspension cable obtained by the method of the present invention has no protrusion. Workability at the time of drawing can be significantly improved.

The material of the suspension wire 5 is STG, IRG, F
All conventionally used materials such as RP can be applied. As the sheath material of the suspension wire 5 and the optical fiber cable core 7, that is, the covering material, all materials conventionally used such as PE, PVC, nylon, and aluminum laminate PE can be applied.

As a method of controlling the feeding speed of the suspension line 5 and the optical fiber cable core 7, a transmission device capable of controlling the speed is provided for each of the suspension line and the optical fiber cable core, and V1 = λ · V2. Control using an electric signal, or mechanically using a gear, gear, etc.
There is also a method of controlling so that 1 = λ · V2. These methods can be appropriately selected and used.

As described above, according to the present invention, as a method of adding an extra length to the cable side, the covering of the suspension line 5 and the optical fiber cable core 7 is simultaneously performed simultaneously while controlling the feeding speed of the suspension line 5 and the optical fiber cable core 7. Due to the extrusion, the production days and cost have been significantly reduced.

Since the feed speed of the suspension wire 5 and the optical fiber cable core 7 is controlled before the sheath is extruded and covered, if the cooling capacity of the cooling water tank is increased, the production speed of the optical fiber cable with the suspension wire can be further improved. . If, unlike the method of the present invention, a method of controlling the take-up speed of the optical fiber cable with a stranded cable after coating the sheath, the wrapped optical fiber cable is wrapped around a capstan for controlling the take-up speed. Unless the suspended fiber optic cable is completely cooled, the target extra length cannot be obtained.
Manufacturing speed cannot be increased.

[0026]

According to the present invention, the following excellent effects are exhibited.

(1) Since the optical fiber cable with a suspension wire is formed at a time by extruding and covering the sheath, the number of necessary steps is reduced from the conventional three steps to one step, thereby shortening the number of manufacturing days and reducing costs. Can be.

(2) Since the feeding speed difference between the suspension wire and the optical fiber cable core is provided by the feeding belt wrap capstan, it is easy to set the extra length ratio.

(3) The molding work of the support, which has been conventionally required, is eliminated, and the production speed is improved.

(4) Since there is no projection like a conventional support, the workability and efficiency of wire drawing work are improved.

(5) Since the feeding speed of the suspension wire and the optical fiber cable core is controlled before the sheath is extruded and covered, if the cooling capacity of the cooling water tank is increased, the cable manufacturing speed can be further improved.

(6) Since the feeding speed of the suspension wire and the optical fiber cable core is controlled before the sheath is applied by the feeding belt wrap capstan, when this is applied to existing equipment, the cooling water tank or the like is modified. Becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a schematic view of a method for manufacturing an optical fiber cable with a suspension wire according to the present invention.

FIG. 2 is a sectional view of a feed belt wrap capstan used in the manufacturing method of the present invention.

FIG. 3 is an optical fiber cable with a suspension wire according to the present invention,
(A) is a sectional view, (b) is a side view, and (c) is a top view.

FIG. 4 is a conventional pre-hanger type optical fiber cable, in which (a) is a cross-sectional view and (b) is a side view.

[Description of Signs] 1 Suspended Wire with Coating 2 Optical Fiber Cable 3 Support 4 Feeding Drum for Suspended Wire 5 Suspended Wire 6 Feeding Drum for Optical Fiber Cable Core 7 Optical Fiber Cable Core 8 Feeding Belt Wrap Capstan 9 Extruder 10 Slit Forming Device DESCRIPTION OF SYMBOLS 11 Cooling water tank 12 Take-up machine 13 Winder 20 Neck 21 Neck slit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Ishii 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable Co., Ltd. (72) Inventor Akira Shoji 5 Hidaka-cho, Hitachi City, Ibaraki Prefecture No. 1-1, Hidaka Factory, Hitachi Cable, Ltd.

Claims (2)

[Claims] 1. A method for manufacturing an optical fiber cable with a suspension wire, wherein a suspension wire and an optical fiber cable core are arranged in parallel and fed out, and a sheath having a gourd-shaped cross-section is collectively extruded and coated on an outer periphery thereof by an extruder. When the feeding speeds of the suspension wire and the optical fiber cable core fed into the extruder are V2 and V1, respectively, V2 <V1 ≦ 1.
A method for manufacturing an optical fiber cable with a suspension wire, characterized by extruding a sheath at a time while controlling the respective feeding speeds so as to obtain 005 · V2. 2. The hanging wire according to claim 1, wherein, when the hanging wire and the optical fiber cable core are extruded at once, a slit is formed intermittently in a gourd-shaped cross section of the neck. Manufacturing method of optical fiber cable.