JPS62278510A - Terminal part for optical fiber cable and its formation - Google Patents

Abstract

PURPOSE:To decrease the external diameter of an optical fiber cable and easily connect it to equipment, and to treat its terminal by removing the spacer except to necessary length and connecting the core, and then forming a projection layer around the outer periphery of the connection part. CONSTITUTION:Jackets 6 and 11 of a cable main body 20 which has an optical fiber core 9 and a flexible insulation conductor 10 in the spiral grooves 8 of the flexible spacer 7 are removed by about 50cm and the spacer 7 is cut while left to 2-3cm. The core 2a of an opposite-side optical fiber cord 2 to be connected is drawn out and the cores are fused and connected together at a point P; and then a fiber 2b having high tensile force and a jacket 2c are slid toward the main body 20 onto a spacer 7', and the outer periphery of the connection part is covered with a heat-shrinkable tube 21, thus treating the terminal. Thus, the cables can be connected by the easy method without any increase in the external diameter.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the terminal portion of an optical fiber cable such as an optical cabling cable used for image transmission between a moving system and a stationary system, and its formation. It is about the method.

[Conventional technology and its problems]

For image transmission between TV cameras, etc. installed in moving systems such as robots, operating carts, running lanes, etc. and monitor TVs, etc. installed in stationary systems, such as monitoring rooms and control rooms, as well as combined image and power transmission. An optical cabtyre cable having an optical fiber or an optical fiber and a flexible insulated conductor is used.

As an example of this conventional optical cabtyre cable,
As shown in the figure, around the tension member 1, an optical fiber cord 2, Pv
The C intervening string 3 and the flexible insulated conductor 4 are made of polypropylene (
PP) Yarns 5 are interposed and this is arranged as a PvC jacket 6.
The electrical equipment in the transmission system has a structure in which the outer sheath 6 is removed at the terminal part,
The optical fiber cord 2, the flexible 1!1 edge conductor 4 are exposed and connected to each other. The connection part C is subjected to mechanical loads such as bending during use, but there is no problem because the optical fiber cord 2 and flexible insulated conductor 4 are strong against such mechanical loads. .

However, the optical cabtyre cable C1 has 1
Since the outer diameter is around 1 mmφ, the maximum winding length that can be wound onto the take-up reel is limited. Therefore, the movement range of the mobile system such as the TV camera is also limited.

In addition, as another optical cabtire cable, as shown in FIG. 3, a spiral groove 8 is formed along the entire length of the outer surface of a linear flexible spacer 7 having a tension member 1 at its axis. , the optical fiber core S and the flexible insulated conductor 1 are placed in this groove 8.
0 and store it in polyethylene tereftate (PE
T) There is a structure in which the device is covered with a PvC jacket 6 via a tape 11.

This cable C2 has an outer diameter of around 7.0 mm, which can be made thinner than the above cable C1, so it is advantageous in terms of the amount of winding on the take-up reel, but it has low mechanical strength, so It is difficult to process the terminal section.

That is, it is connected to electrical equipment using a splice box or a connector, which raises the problem of high costs.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a terminal part of an optical fiber cable that has a small outer diameter and is easy to connect to equipment, and a method for forming the same.

[Means to achieve the purpose]

In order to achieve the above object, the present invention is configured such that an optical fiber is housed in a groove spirally formed in the length direction of a linear flexible spacer, and a coating is provided around the outer periphery of the optical fiber. At the terminal end of the optical fiber cable, the required length of the coating is stripped off from the terminal surface, and the exposed spacer is removed leaving the required length, and the outer periphery of the exposed optical fiber is removed. A coating made of polyvinyl chloride or the like is formed through the high tensile strength fibers, and a protective layer covering the re-coating is formed on the outer surface of the exposed spacer with the optical fiber core interposed therebetween.

By configuring the cable end portion in this way, the cable main body excluding the end portion has the structure of the cable C2 described above and has a small outer diameter, so that the maximum winding length onto the reel becomes long.

On the other hand, the terminal part has a so-called optical fiber cord structure in which the optical fiber core wire is coated with high tensile strength fibers, and since this optical fiber cord is exposed, it has high mechanical strength. This makes it easier to connect to required equipment, especially to mobile systems.

Furthermore, in the method of the present invention for forming the terminal portion of the optical fiber cable C2, when forming the terminal portion of the optical fiber cable C2, a required length of the coating is stripped off from the terminal surface of the optical fiber cable C2, thereby exposing the exposed portion. The spacer is removed leaving a required length, and the optical fiber core of the optical fiber cord is fusion-spliced to the exposed optical fiber core, and then the high tensile strength fiber layer and coating of the optical fiber cord are attached to both the optical fibers. The optical fiber cable is slid over the center to reach the stripped end face of the optical fiber cable, and a protective layer covering the re-coating is formed on the outer surface of the exposed spacer with the optical fiber cord interposed therebetween.

With this configuration, the cable terminal portion of the present invention can be obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings FIGS. 1 to 4.

First, as shown in FIGS. 1 and 2, like the cable Ct, the cable main body 20 is constructed from a linear flexible spacer 7 having a tension member 1 provided at its axis along the entire length in the outer surface length direction. A spiral groove 8 is formed, an optical fiber core S and a flexible insulated conductor 10 are housed in the groove 8, and the PVC is attached via a polyethylene tereft (PET) tape 11.
For example, GI-50/
125 x 2-core + 0.5Cm” x 2-core cable tossle.

At the terminal portion of the cable main body 20 that will be connected to the device, as shown in FIG. The spacer 7 is removed leaving a required length, for example, 2 to 3 CI11.

However, the tension member 1 in the spacer may be left long as necessary and used when fixing the cable.

Next, the optical fiber cord 2 (for example, G
Prepare the required size (for example, around 40c+i) of T-50/125 car core optical cord x 2), pull out the optical fiber core 2a of this cord 2, and connect it to the cable main body 20.
The optical fiber core 9 is fusion spliced.

It is also possible to peel off the coating 2C without pulling out the optical fiber core 2a, and fold back the high tensile strength fiber 2b to avoid tangling, as shown in FIG. 4, to fusion splice both optical fiber cores 2a and 9. can.

After this fusion splicing Vt, only the high tensile strength fibers 2b and the coating 2C of the optical fiber cord 2 are slid toward the cable main body 20 side so that the remaining parts are exposed so as not to apply bending stress to the optical fiber cores 2a and 9. It reaches above the spacer 7'. At this time, as shown in FIG. 2, this spacer 7' is removed by the thickness of the high tensile strength fiber 2b and coating 2c, so that the optical fiber cord 2' (optical fiber core 9 It is preferable to prevent bending stress from being applied to the optical fiber core 9 when the high tensile strength fiber 2b and the coating 2C are applied on the optical fiber cord 2'. coated optical fiber 2
A is truncated including the connection point P with the optical fiber core 9.

Thereafter, as shown in FIG. 1, a heat-shrinkable tube 21 is placed over the spacer 7' with the optical fiber cord 2' and the flexible insulated conductor 4 interposed therebetween, and re-covering 6.2C is performed. ! lFi is formed to complete the formation of the terminal section. The protective layer can also be formed by molding an epoxy resin or the like.

The other end of the cable main body 20 may be configured in the same manner as described above when connected to a moving system; otherwise, for example, when connected to a connection part of a take-up reel, an optical fiber core S or the like may be used. You can connect it directly.

In the optical fiber cable C constructed in this manner, the cable main body 20 is wound around a take-up reel, and the optical fiber cord 2', etc., which is the exposed end thereof, is connected to a moving system. At this time, as mentioned above, the cable main body 20 is considerably thinner than the cable C1, so the maximum winding length on the reel is longer than that using the cable C, and the movable range of the moving system is reduced. It becomes wider. In addition, since the terminal portion that is connected to the mobile system is an optical fiber cord 2 or the like having high mechanical strength, there is no problem at all.

In the above embodiment, the optical fiber core 2a of the optical fiber cord 2 is fusion-spliced to the optical fiber core 9 of the cable body 20, and then the high tensile strength fibers 2b and the coating 2C of the optical fiber cord 2 are connected to the cable body 20. The optical fiber cord 2' is formed as the terminal part of the cable main body 20 by sliding it to the side, but the optical fiber core 2a is pulled out from the optical fiber cord 2 in advance, that is, the cylindrical shape made of the high tensile strength fiber 2b and the coating 2c is formed. It is also possible to form the optical fiber cord 2' at the end of the cable body 20 by inserting the body into the optical fiber core 9.

[Comparative example]

Table 3 below shows a comparison of cable diameters, etc. between an embodiment in which the optical fiber main body 20 is configured as shown in Table 1 below, and a conventional example in which the cable C1 shown in FIG. 5 is configured as shown in Table 2 below.

Table 1 Table 2 Table 3 From these results, it can be confirmed that this example is superior in every respect to the conventional example.

It should be noted that although the embodiments are concerned with cabtire cables, it goes without saying that the present invention can be applied to other cables as well.

〔Effect of the invention〕

Since the present invention is configured as described above, the diameter of the cable main body can be reduced without requiring any special measures for connection with the mobile system as in the past. Therefore, for example, when used as a cabtire cable, there is an effect that the amount of winding on a reel can be increased.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a cutaway front view of essential parts of an embodiment of the optical fiber cable according to the present invention, Fig. 2 is a sectional view taken along line X-X of the terminal portion of Fig. 1, and Fig. 3 1 is a sectional view of the cable body shown in FIG. 1, FIG. 4 is an explanatory view of a method for forming an end portion, and FIG. 5 is a sectional view of a conventional cable. 1...Tension member, 2.2'...
・Optical fiber cord, 2c, 6...Sheath (coating), 7...Spacer, 8...Groove, 2a
, 9... Optical fiber core wire, 2b... High tensile strength fiber, 20... Cable body, 21...
...Heat-shrinkable tube (protective layer). Patent Applicant Tuckwosen Co., Ltd. Agent Kama 1) Bun 2

Claims (4)

[Claims] (1) At the terminal part of an optical fiber cable, which is constructed by storing an optical fiber core in a groove formed in a spiral shape in the length direction of a linear flexible spacer and providing a coating on the outer periphery, the terminal A required length of the coating is removed from the surface, the exposed spacer is removed leaving a required length, and the outer periphery of the exposed optical fiber is coated with polyvinyl chloride or the like via high tensile strength fibers. A coating consisting of
A terminal portion of an optical fiber cable, characterized in that a protective layer is formed on the outer surface of the exposed spacer to cover both the coatings with the optical fiber core interposed therebetween. (2) The terminal portion of an optical fiber cable according to claim (1), wherein the protective layer is made of a heat-shrinkable tube. (3) When forming the terminal part of an optical fiber cable, which consists of storing an optical fiber core in a groove formed in a spiral shape in the length direction of a linear flexible spacer and providing a coating around the outer periphery. , stripping off a required length of the coating from the terminal surface thereof, removing the exposed spacer leaving only the required length, and fusion-splicing the optical fiber core of the optical fiber cord to the exposed optical fiber core; Next, the high tensile strength fibers and coating of the optical fiber cord are slid over the two optical fiber cores to reach the stripped end face of the optical fiber cable, and the optical fiber cord is interposed on the outer surface of the exposed spacer. A method for forming an end portion of an optical fiber cable, the method comprising: forming a protective layer covering both the coatings. (4) The method for forming an end portion of an optical fiber cable according to claim (3), wherein the protective layer is made of a heat-shrinkable tube.