JPH0556545A - Protection box for communication cable joint - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a protection box for a communication cable connecting portion which can easily cope with a change in size of the connecting portion of the communication cable and can be mass-produced at a low price. [Structure] The protective box body 11 is divided into four parts along the longitudinal direction and the radial direction of the communication cable 12 into four parts.
3, each divided part 13 is formed by injection-molding plastics, and the communication cable 12 is covered with two pairs of upper and lower divided parts 13a in which divided surfaces along the longitudinal direction are combined to form a tubular body. After connecting the split surfaces of the two sets of split part cylinders 13a along the radial direction with the fitting pin 16 and the fitting hole 17, these are joined together by welding 21 or an adhesive. It is a thing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective box for a communication cable connecting portion, and more particularly to a protective box for a communication cable connecting portion for protecting a direct buried portion of a communication cable from excavation work.

[0002]

2. Description of the Related Art Conventionally, a protective box for a communication cable connecting portion of this type is constructed as shown in FIGS.

As shown in FIG. 5, the connecting portion 1a of the communication cable 1 which is directly buried in the ground is used for the sewage work after the direct buried.
In order to protect it from gas piping work and the like, both ends are covered by a protective box 2 having a cylindrical body whose diameter is successively reduced.
The cable inlet / outlet 3 of the protective box 2 is sealed with a sealing material 4 as needed to waterproof the connecting portion 1a, and a compound 5 is injected into the protective box 2.

As shown in FIG. 6, the protection box 2 is
Is formed into a structure that is divided into two along the longitudinal direction of the communication cable 1, and the bolts and nuts 6 are fastened to the flange portions 2c and 2d formed on both edges in the longitudinal direction of the respective divided parts 2a and 2b. The divided parts 2a and 2b are integrated together.

Further, the upper divided part 2a of the protective box 2
Has an injection hole 7 for injecting the compound 5 into the protective box 2, and the lower divided part 2b has a protective box 2
A seat 8 for improving the seating is formed, and the injection holes 7 and the seat 8 are manufactured to have exactly the same size. The size of the protective box 2 needs to be formed according to the size of the connecting portion 1a of the communication cable 1, and usually has a diameter of 60 to 200 mm and a length of 500 to 1200 mm.
Protective box 2 is used. In particular, since the connecting portion of the optical communication cable is relatively large, the protective box 2 is also formed in a large size accordingly.

The material of the protective box 2 must be selected in consideration of mechanical strength, water resistance and chemical resistance. Usually, FRP is used, but since the product size is large, a molding die is first prepared, and glass fiber and resin are manually laminated in this molding die to commercialize it.

[0007]

By the way, in the conventional protective box 2 for the communication cable connecting portion, since the glass fiber and the resin are manually laminated in the molding die, the mass production is not possible. It was possible.

Further, the number of man-hours required is too large, and it takes a long time to commercialize the product.

Further, a new molding die had to be produced each time the size of the connecting portion 1a of the communication cable 1 changed.

From these points, there is a problem that the product becomes expensive.

In view of the above problems, an object of the present invention is to provide a protective box for a communication cable connecting portion which can easily cope with a change in the size of the connecting portion of the communication cable and can be mass-produced at a low price. It is in.

[0012]

According to the protective box for a communication cable connecting portion of the present invention, the above-mentioned object is divided into four parts in which the protective box main body is divided along the longitudinal direction and the radial direction of the communication cable. It consists of parts, and each divided part is polypropylene, PBT (polybutylene terephthalate), PP
Two pairs of upper and lower split parts are formed by injection-molding plastics such as S (polyphenylene sulfide), PET (polyethylene terephthalate), etc., and the communication cable is formed into a cylindrical body by combining the split surfaces along the longitudinal direction. By covering and connecting the split surfaces along the radial direction of these two sets of split part cylinders with the fitting pin and the fitting hole, and then integrating them by welding or adhesive, To be achieved.

[0013]

According to the above construction, the protective box body is composed of the four divided parts which are divided in the longitudinal and radial directions of the communication cable. Therefore, in order to manufacture a protective box, it is sufficient to manufacture an injection mold of one divided part,
Since the size of the molding die is extremely small, the die allowance can be reduced.

Further, since plastics are injection-molded by the above-mentioned injection mold to manufacture divided parts, mass production is possible and the unit price of the product can be greatly reduced.

Further, the communication cable is covered with two pairs of upper and lower split parts which are tubular bodies formed by combining split surfaces along the longitudinal direction, and the split surfaces of the two split parts tubular bodies along the radial direction. Are connected by a fitting pin and a fitting hole. Therefore, a protective box of an arbitrary length can be formed by interposing an intermediate part appropriately combined with the tubular body between these two sets of split part tubular bodies, and as a result, the injection molding die The types can be reduced.

In this way, a protective box for a communication cable connecting portion which can easily cope with a change in the size of the connecting portion of the communication cable and can be mass-produced at a low price is manufactured.

The strength can be sufficiently put to practical use by connecting or reinforcing the connecting portions of the two sets of divided part cylinders by welding or an adhesive.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a protective box for a communication cable connecting portion according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 4, the protective box main body 11 of the protective box 10 for the communication cable connecting portion is divided into four parts along the longitudinal direction and the radial direction of the communication cable 12. It consists of parts 13.

These divided parts 13 are formed in the same shape, and FIG. 1 shows one of the divided parts 13. The divided part 13 has a shape in which a cylindrical body whose one end is successively reduced in diameter is halved. A flange portion 14 is formed on a divided surface of the divided part 13 along the longitudinal direction, and a bolt hole 15 for inserting a bolt (not shown) is formed in the flange portion 14. .. On the other hand, on the split surface of the split part 13 along the radial direction, a fitting pin 16 for connecting the split surfaces to each other and a fitting pin 16 for inserting the fitting pin 16 in position are inserted. A fitting hole 17 is formed.
Specifically, the fitting pins 16 and the fitting holes 17 are formed on the arc-shaped divisional surfaces at equal intervals along the circumferential direction.

A holding base 18 for holding the connecting portion 12a of the communication cable 12 is integrally formed inside the divided part 13. And this holding table 1
A compound injection hole 19 for injecting the compound into the protective box 10 is formed in the vicinity of 8.

Further, the divided parts 13 are formed by producing an injection mold (not shown) and injection molding plastics by the injection mold. As the plastics, PBT (polybutylene terephthalate) having excellent mechanical strength, PPS (polypropylene sulfide), polypropylene, PET (polyethylene terephthalate), etc., which are attracting attention as having heat resistance and chemical resistance, are adopted. .. The fitting pin 16 may be attached at the time of injection molding of the divided part 13 or may be attached after molding.

Then, the connecting portion 12a of the communication cable 12 is formed by the four divided parts 13 thus formed.
Are covered. Specifically, as shown in FIG.
The connecting portion 12a of the communication cable 12 is covered with two pairs of upper and lower split parts 13a which are cylindrical bodies formed by combining split surfaces along the longitudinal direction. At that time, the flange portions 14 of the divided parts 13 are brought into contact with each other, and the bolts 20 are inserted into the bolt holes 15 formed in the flange portions 14 and screwed and fastened with a nut.

Next, as shown in FIG. 3, the split surfaces of the two sets of split part cylinders 13a along the radial direction are connected by the fitting pins 16 and the fitting holes 17. It
After that, the connecting portion is integrated by welding 21 or an adhesive, and the connecting portion 12a of the communication cable 12 is covered with the protective box 10.

The connection portion 12 of the communication cable 12 is also provided.
When the length of a is long, the protective box 10 is configured as shown in FIG.

As shown in the drawing, a semi-cylindrical intermediate part 18 is provided between the two sets of split part cylinders 13a in combination with the cylinder, and the intermediate part cylinder 18a is fitted with the fitting pin. 16 and the fitting hole 17 are used to integrate with the two sets of split part cylinders 13a, so that the longitudinal dimension of the protective box 10 is increased. The length of the intermediate part 18 is set according to the length of the connecting portion 12a of the communication cable 12. Further, the intermediate part 18 is formed by producing an injection molding die (not shown) similarly to the divisional part 13 and injection molding plastics by the injection molding die.

The cable entrance 22 of the protection box 10
Is sealed with a sealant (not shown) to waterproof the connecting portion 12a, and a compound is injected into the protective box 10 through the compound injection hole 19 (not shown). Is.

Next, the operation of the above embodiment will be described.

As described above, the protective box main body 11 of the protective box 10 for the communication cable connecting portion is composed of the four divided parts 13 which are divided in the longitudinal direction and the radial direction of the communication cable 12. Therefore, for example, in the case of manufacturing the protective box 10 having a length of 1 m, the half length is 50 cm.
It suffices to produce an injection mold of the divided part 13. As a result, the size of the molding die becomes extremely smaller than that of the conventional one, so that the die allowance can be reduced.

Since the divided parts 13 are manufactured as injection molded products, mass production is possible and the unit price of the product can be greatly reduced.

Furthermore, the above-mentioned two sets of split part cylinders 13a
Since the intermediate part tubular body 18a having an appropriate length according to the length of the connecting portion 12a of the communication cable 12 is interposed between the two, a protective box of an arbitrary length can be formed. The number of molds can be reduced.

As described above, it is possible to easily cope with a change in the size of the connecting portion 12a of the communication cable 12 and to mass-produce the communication cable connecting portion at a low price.
0 is produced.

The strength can be sufficiently put to practical use by integrally reinforcing the connecting portions of the two sets of split part cylinders 13a by welding 21 or an adhesive. The applicant adopted polypropylene as the material, assembled the four injection-molded four divided parts 13 as described above, and manufactured the protection box 10 which was joined and integrated by the heat welding 21. It has been confirmed that there is no problem in terms of mechanical strength by burying the protection box 10 in the ground 1 m.

[0034]

As described above, according to the protective box for the communication cable connecting portion according to the present invention, it is possible to easily cope with the change in the size of the connecting portion of the communication cable, and it is possible to mass-produce at a low price. It has the excellent effect of being

[Brief description of drawings]

FIG. 1 is a perspective view showing divided parts in an embodiment of a protection box for a communication cable connecting portion according to the present invention.

FIG. 2 is a plan view showing a combination state of a pair of split parts in an embodiment of a communication cable connection part protection box according to the present invention.

FIG. 3 is a vertical cross-sectional view showing a connecting portion of divided parts in an embodiment of a protection box for a communication cable connecting portion according to the present invention.

FIG. 4 is a plan view showing a state in which an intermediate part is used in an embodiment of the protection box for a communication cable connecting portion according to the present invention.

FIG. 5 is a plan view showing a conventional protection box for a communication cable connecting portion.

6 is a view taken along the line AA of FIG.

[Explanation of symbols]

 11 Protective Box Main Body 12 Communication Cable 13 Divided Parts 13a Divided Parts Tube 16 Fitting Pin 17 Fitting Hole 21 Welding

Claims (2)

[Claims] 1. A protective box body is composed of four divided parts which are divided in the longitudinal direction and the radial direction of the communication cable, and each of the divided parts is formed by injection-molding plastics. The connecting portion is covered with two pairs of upper and lower split parts which are formed by combining split surfaces along the longitudinal direction into a tubular body, and the split surfaces along the radial direction of the two split parts tubular bodies are fitted with fitting pins. A protective box for a communication cable connecting part, characterized in that after connecting with a dowel, these are joined together by welding or an adhesive. 2. The plastics are polypropylene, PBT (polybutylene terephthalate), PPS.
(Polyphenylene sulfide), PET (polyethylene terephthalate), It is characterized by the above-mentioned.
Protective box for communication cable connection described in.