JPH0635205Y2 - Non-metal optical cable tension terminal fixing structure - Google Patents

Description

[Detailed Description of the Invention] "Industrial field of application" The present invention relates to a fixing structure of a tensile terminal used when a non-metal optical cable is extended.

“Prior Art” Conventionally, as an optical cable, there is a non-metal optical cable for the purpose of preventing the influence of electromagnetic induction and reducing the weight of the cable. As a fixing structure of the pulling terminal when such a non-metal optical cable is extended, for example, a structure shown in FIG. 2 is known.

In FIG. 2, reference numeral 1 is a non-metal optical cable, and 2 is a metal cap. In the non-metal optical cable 1, the sheath, the optical fiber core wire, etc. are removed at the end,
The end 3a of the tension member 3 made of P is exposed.
The metal cap 2 includes a cylindrical tubular portion 4 and a spherical canopy portion 5 that closes one opening of the tubular portion 4.
The cylindrical portion 4 has an axial length longer than that of the terminal portion 3a of the tension member 3, and an inner diameter thereof larger than that of the non-metal optical cable 1. An insertion opening 6 is formed in the center of the canopy portion 5, and an eyebolt 7 is inserted into the insertion opening 6 with its screw portion protruding outside the cap. Then, from the end 3a of the tension member 3 to the end of the non-metal optical cable is inserted into the metal cap 2, and the internal space of the metal cap 2 is filled and solidified with an adhesive 8 such as epoxy resin. Thus, the metal cap 2 is integrally attached to the non-metal optical cable 1.

In order to extend the non-metal optical cable 1 having such a fixed structure of the pulling terminal, first connect a wire to the eyebolt 7, then pull the wire with a cable towing vehicle or the like,
Thereby, the non-metal optical cable is laid at a predetermined position.

[Problems to be Solved by the Invention] By the way, in the above-mentioned structure for fixing the tensile end of the non-metal optical fiber, there are the following problems when the non-metal optical cable 1 is extended.

When the eyebolt 7 having the above-mentioned fixed structure is pulled when the non-metal optical cable 1 is extended, a tension acting in the pulling direction inside the cap and a tension against the above-mentioned tension due to the weight of the non-metal optical cable 1 are generated, which conflict with each other. The tension acting in the direction tends to cause cracks in the adhesive 8 inside the cap. In this case, the epoxy resin near the canopy portion 5 has its tensile strength increased by the eyebolt 7, and the adhesive 8 from the opening to the central portion has its tensile strength increased by the tension member 3.
The adhesive 8 between the end portion 3a of the tension member 3 and the eyebolt 7 is not alone, and therefore has a relatively small tensile strength as compared with other portions, and thus is more likely to crack than other portions. On the other hand, the adhesive 8 has good adhesiveness with FRP, but has inferior adhesiveness with metal as compared with the above FRP. Therefore, when the tension generated inside the cap exceeds the tensile strength of the adhesive 8, the adhesive 8 between the end 3a of the tension member 3 and the eyebolt 7 is cracked, which causes the adhesive 8 and the metal cap 2 to break. The adhesiveness with
As a result, the non-metal optical cable 1 comes out of the metal cap 2 together with the adhesive 8.

[Means for Solving Problems] Therefore, in this invention, a notch is formed at the tip of the tension member of the end of the non-metal optical cable, and a wedge is held at the notch, and the tip of the tension member holding the wedge is held. Part is inserted into a tubular part of a sleeve consisting of a tubular part and a pulling part that closes one opening of the tubular part, the adhesive is filled in the tubular part, and a narrowed part is formed in the vicinity of the opening part of the tubular part. By doing so, the above problems were solved.

[Embodiment] FIG. 1 is a view showing an embodiment of the present invention, in which reference numeral 10 is a non-metal optical cable and 11 is a sleeve. Similar to the non-metal optical cable 1 shown in FIG. 2, the non-metal optical cable 10 has a sheath, an optical fiber core wire and the like removed at its end, and the end 12a of the FRP tension member 12 is exposed. The end 12a of the tension member 12 is divided into two parts along the lengthwise direction of the tension member 12 from the tip end surface 12b thereof to the vicinity of the central portion of the end member 12a. Are formed. A wedge 14 made of a copper wire, a steel plate or the like is sandwiched and fixed to the cut portion 13 via an adhesive 15 such as an epoxy resin. In this case, the end portion 12a of the tension member 12 having a large diameter due to the wedge 14 being held.
The maximum diameter of is slightly smaller than the inner diameter of the cylindrical portion of the sleeve 11 described later.

The sleeve 11 is made of metal such as iron in which a cylindrical tubular portion 16 and a pulling portion 17 that closes one opening of the tubular portion 16 are integrally configured. The tubular portion 16 has an inner diameter slightly larger than the maximum diameter of the end portion 12a of the tension member 12 with the wedge 14 held between the end portions 12a of the tension member 12 and the end portion 12a of the tension member 12. It is constructed slightly shorter than the length. Further, a curved surface portion 16a is formed by cutting and rounding the corner portion on the inner peripheral edge of the opening portion of the tubular portion 16, whereby the tubular portion 16 is bent when forming a throttle portion to be described later. When an unexpected accident occurs,
Due to the inner peripheral edge of the opening, the end 12a of the tension member 12 is
It is designed not to hurt. The tension portion 17 is the above-mentioned tubular portion.
A disc portion 18 that closes one opening of the disc 16, a disc-shaped large-diameter portion 19 that is integrally connected to the disc portion 18, and a threaded portion 20 that is integrally connected to the large-diameter portion 19. ing. A male screw 21 is formed on the outer peripheral surface of the screwing portion 20, and a female screw such as a pulling tool (not shown) is screwed into the male screw 21 to form a sleeve.
11 is fixed to a towing tool and is towed.

The end portion 12a of the tension member 12 is inserted into the cylindrical portion 16 of the sleeve 11. In this case, an adhesive 22 such as an epoxy resin is filled and solidified between the end portion 12a of the tension member 12 and the inside of the tubular portion 16, whereby the end portion 12a of the tension member 12 is fixed in the sleeve 11. Has been done. Further, the tubular portion 16 is narrowed slightly toward the center side of the opening portion thereof, so that the small-diameter throttle portion is formed.
23 are formed. Here, the inner diameter of the throttle portion 23 is made slightly larger than the outer diameter of the end portion 12a of the tension member 12, so that the end portion 12a does not receive a compression pressure when the throttle portion 23 is formed. ing. Further, the narrowed portion 23 is formed after the adhesive 22 is filled in the tubular portion 16 and before the adhesive 22 is solidified, whereby a space is not formed in the tubular portion 16 and the adhesive 22 is filled therein. There is.

In order to fabricate such a terminal fixing structure for a non-metal optical cable, first, the end 12a of the exposed tension member 12 of the non-metal optical cable 10 is moved from the end face 12b to the end 12 thereof.
The notch 13 is formed by dividing the a into the vicinity of the center. Next, the adhesive 15 is injected and applied to the cut portion 13, and the wedge 14 is sandwiched and fixed to the cut portion 13 via the adhesive 15. Next, an adhesive 22 is applied to the outer peripheral surface of the end portion 12a of the tension member 12 holding the wedge 14 on the tip side, and the tubular portion 16 of the sleeve 11 is filled with the adhesive 22.
In this state, the end portion 12a of the tension member 12 is inserted into the tubular portion 16, and the tip end surface 12b of the tension member 12 is brought into contact with the disc portion 18 or in the vicinity thereof. In this case, the same adhesive 22 as the adhesive 15 is preferably used, but the adhesive 22 is not necessarily limited to this. Then, the tube portion 16
Under the condition that the inside is filled with the adhesive 22 without forming a space, the vicinity of the opening of the tubular portion 16 is squeezed and the narrowed portion 23
Is formed, and then the adhesive 22 is solidified to obtain a tensile terminal fixing structure.

In order to extend the non-metal optical fiber cable 10 having such a fixed structure of the pulling end, the pulling tool is first screwed to the threaded portion 20 of the pulling portion 17 of the sleeve 11, and then the pulling tool is connected to the wire. A non-metal optical cable is laid at a predetermined position by pulling the cable with a cable towing vehicle or the like.

In such a non-metal optical cable pulling end fixing structure, since the tip end side of the end 12a of the tension member 12 has a large diameter by sandwiching the wedge 14 in the notch 13, the pulling part 17 of the sleeve 11 is pulled. Even if the solidified adhesive 22 is cracked at this time, the adhesive 22 is locked to the narrowed portion 23, and the end 12a having a large diameter is locked to the adhesive 22. Are prevented from coming out of the sleeve 11. Further, since the adhesive 22 is filled in the tubular portion 16 and the narrowed portion 23 is formed, the adhesive 22 is solidified.
22 is sealed by the squeezing portion 23 and is adhered and solidified over the entire inner surface of the tubular portion 16 and the outer peripheral surface of the end portion 12a of the tension member 12, whereby the end portion 12a of the tension member 12 and the sleeve 11 are connected. A high bond strength is obtained during. Further, in this tension terminal fixing structure, the tension portion 17 of the sleeve 11 is
Since the threaded portion 20 is provided on the shaft, connection with the pulling tool can be easily performed.

In addition, in the above-described embodiment, the single throttle portion 23 is formed on the tubular portion 16, but two or more throttle portions may be formed.

[Advantage of Invention] As described above, in the tension terminal fixing structure of the non-metal optical cable of the present invention, the notch is formed at the tip of the tension member of the end of the non-metal optical cable, and the wedge is sandwiched between the notches. The end portion of the tension member holding the wedge is inserted into the tubular portion of the sleeve including the tubular portion and the pulling portion that closes one opening of the tubular portion, and the tubular portion is filled with the adhesive to Since the narrowed portion is formed near the opening of the, the tip of the end of the tension member has a large diameter due to the wedge being held, so the adhesive that has solidified when the sleeve is pulled Even if a problem occurs, the adhesive is locked to the narrowed portion, and the end portion having a large diameter is locked to the adhesive to prevent the end portion from coming out of the sleeve. You can Further, if the adhesive is solidified after forming the narrowed portion, the adhesive is sealed by the narrowed portion and adheres over the entire inner surface of the cylinder and the outer peripheral surface of the end of the tension member. And solidify, whereby a high bond strength can be obtained between the end of the tension member and the sleeve.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a tension terminal fixing structure for a non-metal optical cable of the present invention, and FIG. 2 is a side sectional view showing an example of a conventional tension terminal fixing structure. 10 …… Non-metal optical cable, 11 …… Sleeve, 12a …… Tension member end, 13 …… Notch, 14 …… Wedge, 15 …… Adhesive, 16 …… Cylinder, 17 …… Tensile, 22 …… Adhesive, 23 …… Squeezer.

Claims (1)

[Scope of utility model registration request] 1. A notch is formed at the tip of a tension member at the end of a non-metal optical cable, and a wedge is sandwiched between the notches, and the tip of the tension member sandwiching the wedge has a tubular portion and this tubular portion. Inserted into the tubular part of the sleeve consisting of the tension part that closes one opening,
A tensile terminal fixing structure for a non-metal optical cable, characterized in that an adhesive is filled in the tubular portion, and a narrowed portion is formed near the opening of the tubular portion.