JPS5938715A - Method for reinforcing juncture of optical fibers and its reinforcing member - Google Patents

Abstract

PURPOSE:To enable simple and quick reinfocement without the formation of gaps and holes by inserting the juncture of optical fibers into the hollow groove of a reinforcing member of a thermoplastic resin, and erasing the recess by heat thereby enclosing the juncture. CONSTITUTION:This invention relates to the reinforcement of a juncture wherein a pair of covered optical fibers 1A, 1B having covering removed parts 3A, 3B on the connection end side are butted and melt stuck to each other. A hollow groove 5 is formed to a thermoplastic reinforcing member 4 along the external longitudinal direction thereof and after the juncture of the optical fibers is fitted therein, the memeber 4 is deformed by heating and pressurizing means to erase the groove 5, whereby the juncture is enclosed. The member 4 consists of only the thermoplastic resin and the groove 5 has the shapes differing between the groove part 6 at the middle and the groove parts 7a, 7b at both ends; the groove parts 7a, 7b are made larger. Another reinforcing member 4 is embedded internally with a tensile material 8 made of stainless steel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reinforcing an optical fiber connection portion and a reinforcing member thereof.

In the optical fiber fusion splicing method, which is often used to achieve a low-loss splicing effect, a pair of coated optical fibers (1)A, (1), called optical fiber cores, etc., are connected as shown in Figure 1.
The coating layer and the coating layer were removed from the end of B, and the coated portion +21 A J2) was cut into a predetermined length. After that, the ends of both coating removal parts (3)A and (3)B are butted against each other and fused and spliced by electric discharge heating, laser heating, or the like.

Such an optical fiber connection part has coating removal parts (3)A, (3)
The fiber is in the state of a strand made of 1B, and therefore has poor strength.To compensate for this, reinforcing means are taken at the connection.

Conventionally, as reinforcement means of this type, there have been methods such as covering the outer periphery of the connection part with a vibrator made of metal such as stainless steel, or methods of covering a V-groove plate and a lid, but in the case of the former, the vibrator and the connection part When there is a gap between the pipe and the pipe, the optical fiber connection part (strands) protrudes within the pipe due to expansion and contraction of the optical fiber coating due to temperature changes, causing buckling, which increases transmission loss. In the case of the latter, air bubbles tend to get mixed in when bonding each plate and the connection part, and this makes it impossible to completely eliminate increased loss and breakage.

Other methods include reinforcing by molding and reinforcing by heat-shrinkable tubes, but these methods have problems in that they are too time-consuming and the reinforcing effect is not sufficient.The present invention aims to solve the above problems by using optical fibers. The purpose is to provide a method and a reinforcing member for reinforcing the connecting portion, and the specific method and structure will be described below with reference to the illustrated embodiments.

Figures 2 (a) to 2) all show reinforcing members (4) according to the present invention, and these reinforcing members (4) are made of thermoplastic resins such as polyamide and polyethylene, or are made of thermoplastic resins such as polyamide and polyethylene, or are made of thermoplastic resins with tensile strength It consists of a composite play with wood.

In the above I, the reinforcing member (4) in FIG. 2(a) is made of only thermoplastic resin, and the reinforcing member (4) is
A groove (5) is formed here, and this groove (5) has a shape with a groove (6) in the middle in the longitudinal direction and grooves (7) a and (7) b at both ends. The grooves (1)a and (7N) at both ends are larger than the middle groove (6).The reinforcing member (4) in Figure 2 (B) is different from that in Figure 2 (A). The tensile strength material (8) is made of metal such as stainless steel or FRP.

On the other hand, the reinforcing member (4) in Fig. 2 (c) has a shape similar to that of a thermoplastic resin cylinder with longitudinal slits, and its grooves (5) are also uniform in the longitudinal direction. It has a shape.

Furthermore, the reinforcing member (4) shown in Fig. 2) has a plurality of tensile strength U' +8] +8 in the reinforcing member (4) shown in Fig. 2 (c).
1 (8)... is buried.

Note that the cross-sectional shape of the groove Φ) may be a rectangular shape such as a ■ shape, or a circular arc shape.

Next, an embodiment of the method of the present invention carried out using the reinforcing member (4) shown in FIG. 2 (B) will be explained with reference to FIGS. The optical fiber connection part shown in Fig. 1 mentioned above is fitted into the groove (5) of (4).
At this time, the covering removal part +3+ A, +3) B is inserted into the intermediate groove part (6), and the covering part (2) A, (2)
The ends of B are inserted into the grooves L7) a and (71b) at both ends.

After this, the reinforcing member (4) that can contain the optical fiber connection part is set in a heating and pressurizing mold (9), where the reinforcing member (4) is heated to soften the thermoplastic resin, At the same time, pressure is applied to erase the concave groove (51), thereby completely enveloping the outer periphery of the optical fiber connection part as shown in FIG. 3(B) and reinforcing the connection part.

Of course, even if the reinforcing member (4) shown in Fig. 2 (A) and (C) is used, the optical fiber connection part can be reinforced in the same way as above. For example, the reinforcing member (4) shown in Fig. 2) In the example used, a reinforced state as shown in FIG. 4 is obtained.

At this time, if the tensile strength pad (8) is embedded within the reinforcing member (4), the reinforcing effect will be higher.

As explained above, the method of the present invention connects a pair of coated optical fibers F having coat removal parts (3)A and (3)B on the connection end side.
ill A and ill B are the respective coating removal parts +3) A
, (3) In a method for reinforcing an optical fiber connection part in which the ends of B are butted together and fusion spliced, the reinforcing member (4) made of thermoplastic resin is provided with a concave groove (5) along the longitudinal direction of its outer periphery. ) is formed, and after fitting the optical fiber connection part into the groove (5), the reinforcing member (4) is deformed by heating and pressurizing means to erase the groove (5). It is characterized by enclosing the connection part.

Therefore, in the case of the method of the present invention, the optical fiber connection part can be reinforced by simply fitting the optical fiber connection part into the groove (5) and heating and pressurizing the reinforcing member (4), so no skill is required and on-site In addition, since the reinforcing part (4) adheres closely to the outer periphery of the optical fiber connection, there is no formation of pores or voids, which can prevent the formation of optical fiber connections. Buckling, breakage, and increased transmission loss are eliminated, and the mechanical properties, temperature characteristics, transmission characteristics, etc. become satisfactory.

Furthermore, the reinforcing member (4) of the present invention is made of thermoplastic resin, and has a concave groove (4) for fitting the optical fiber connection part in the longitudinal direction of the outer circumference.
Since the reinforcing member (4) is characterized by the formation of a By using it, the implementation becomes efficient,
Moreover, it can be done without any problem.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an optical fiber connection part, Figures 2 (a) to 2) are perspective views and sectional views showing various examples of reinforcing members according to the method of the present invention, and Figures 3 (a) and (b) are illustrations of the present invention. A vertical front view and a vertical side view showing an example of reinforcing the optical fiber connection part according to the invention method, and FIG. 4 is a vertical side view showing the other side of the same as above (IIA, +IIB... Coated light fiber +21
A, +21B...Coating part +31 A, f31B...Coating removed part (4
)...Reinforcement member (5)...Concave groove (6), t7) a, t71 b..." Mizobe Patent applicant's agent Patent attorney Ifuji Akira Figures 1 and 2 Figure 3 (4) C 4 Figure 162 Shirakata Shirane, Oaza Shirakata, Tokai Village, Naka District, Ibaraki Prefecture, Nippon Telegraph and Telephone Public Corporation, Ibaraki Telecommunications Research Institute [Co., Ltd.] Inventor: Makoto Furuyo - Oaza Shiro, Tokai Village, Naka District, Ibaraki Prefecture 162 Shirane, Nippon Telegraph and Telephone Public Corporation, Ibaraki Telecommunications Research Institute ■Applicant: Nippon Telegraph and Telephone Public Corporation

Claims (3)

[Claims] (1) In a method for reinforcing an optical fiber splicing portion, in which a pair of coated optical fibers having a sheath removed portion on the splicing end side are fusion spliced with the tips of the sheath removed portions abutting each other, thermoplastic resin A concave groove is formed along the longitudinal direction of the outer circumference of the rod-shaped reinforcing member, and after fitting the optical fiber connection part into the concave groove, the reinforcing member is deformed by heating and pressing means to form the concave groove. A method for reinforcing an optical fiber connection, characterized in that the groove is eliminated and the connection is thereby encapsulated. (2) A reinforcing member for an optical fiber splicing portion in which a pair of coated optical fibers having a sheath removed portion on the splicing end side is fusion spliced with the tips of the sheath removed portions abutted against each other, the reinforcing member being made of thermoplastic resin. A reinforcing part for an optical fiber connection part, characterized in that a groove for fitting the optical fiber connection part is formed in the longitudinal direction of the outer periphery. (3) The reinforcing member 0 for an optical fiber connection section according to claim 2, wherein the concave groove is such that the grooves at both ends in the longitudinal direction are larger than the groove in the middle in the longitudinal direction.