JPS6333488Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to branch connections of electric cables.
In particular, the present invention relates to the provision of a branch connection having excellent waterproof properties and mechanical properties in a branch connection involving insulation treatment performed at a cable installation site.

[Conventional technology]

For cables used for power supply to buildings, tunnels, etc., in order to shorten the construction period or improve quality, branch cables are connected to the main cable in advance at the cable manufacturing factory, and the branch connections are molded. A so-called prefabricated branched cable insulated with resin coating is used.

FIG. 1 shows such a prefabricated branched cable, in which branch portions 3 are formed at predetermined intervals in the longitudinal direction of a main cable 1, and branch cables 2 extend in the form of branches from the branch portions 3. .

The set intervals of the branch portions 3 are determined in advance by the cable manufacturing factory in accordance with the planned branch cable installation position at the cable installation site.

As mentioned above, the branch connection section insulated by resin molding has obtained favorable results in terms of waterproof properties and mechanical properties, and the reason why it is put into practical use is based on the satisfaction of these properties.

However, with prefabricated cables with branching, the location of the branching part is determined at the cable manufacturing stage before installation, making it impossible to accommodate changes or additions to the branching location that often occur when installing cables on site. Therefore, it was necessary to carry out insulation protection treatment for the branch connection portion by a means different from that for the branch portion which is pre-molded as described above.

In addition, the molding machine is transported to the installation site,
It has been considered to construct the branch section by such molding, but in these days when space at cable installation sites is restricted, it is difficult to work with a large molding machine, and it is not practical. Further, the main cable sheath is made of vinyl or polyethylene, and in particular, the latter resin has poor adhesion to the resin to be molded, and there is a fear that the waterproof properties cannot be improved.

Conventionally, insulating branch connections at cable installation sites involves wrapping them with insulating tape or using separately formed insulating covers.

[The problem that the idea aims to solve]

Insulating structures wrapped with insulation tape have problems with waterproof and mechanical properties, so it is necessary to make the tape-wrapped branch connections mechanically robust and cover them with a waterproof protective box, which is not practical. There was a problem.

On the other hand, in the case of a molded insulating cover, since it is a molded body made of resin such as vinyl, the mechanical properties of the cover itself are satisfactory.
In addition, the main cable and the branch cables that extend branch-like from the main cable are passed through and are split into two to incorporate the branch connection, which makes it easy for moisture to enter, so the cover is waterproof. If the compound is filled, a predetermined waterproof property can be obtained, which is practical.

However, in this method, the branch cable is inserted through a hole in a pre-formed insulating cover, so when tension is applied to the branch cable, tension is applied directly to the branch connection between the cable and the main cable. There was also a risk of a short circuit between the phases if the core wire at the connection part broke and the insulated wire cores of each phase were housed in a common sheath.

Such problems have become more pronounced as the diameter of the small-sized branch cable becomes smaller.

In view of the problems of the prior art described above, the purpose of the present invention is to insulate the branch connection by covering it with a pre-formed insulation protection cover, which not only provides waterproof properties but also provides mechanical protection for the branch connection. The object of the present invention is to provide a branch connection section for this type of cable that is sufficiently designed and has no practical problems in terms of mechanical properties.

[Means to solve the problem]

In order to accomplish this purpose, the branch connection part of the present invention is based on molding of resin, which is an insulating protection cover that covers the branch connection part between the trunk cable and the branch cable, and is its own constituent material. The cable is integrally joined on the circumference of the cable to allow the branch cable to pass through it, and the insulation protection cover is provided with a cut that does not reach the part where the branch cable passes through, and the cable is inserted into the insulation protection cover through this cut. The trunk cable is connected to the terminal of the branch cable which is led out through the insulating protection cover penetrating portion.

〔Example〕

Below, Figures 2 and 3 show an embodiment of the present invention.
This will be explained in detail with reference to the drawings.

FIG. 2 shows the structure of a protective insulating cover with a branch cable used for branch connections. The insulation protection cover 4 is molded together with the branch cable 2 using a resin such as soft vinyl chloride. That is, the insulating cover 4 is integrally joined to the periphery of the branch cable 2 at a position set back from the connection terminal 2a thereof based on molding of resin, which is its own constituent material, and thereby penetrates the branch cable. This is what I did. By applying a surface treatment such as applying an adhesive to the penetrating portion of the branch cable 2, the integration of the insulating cover 4 to the branch cable can be enhanced. All of these can be done at the cable manufacturing factory.

The insulating protective cover 4, through which the branch cable 2 is passed through in the jointed and integrated state, is a housing that contains therein the connection terminal 2a of the branch cable 2 led out through the jointed and integrated state. A chamber 4a and a cable insertion hole 4 connected to both ends of the chamber 4a
The cable insertion hole 4b on one side is formed independently of the penetrating portion of the branch cable 2 via a prong 10. The cover 4 has a storage chamber 4a and a cable insertion hole 4 from its outer surface.
Cut 7 reaching the inner wall surface defining b, 4b
is formed, thereby facilitating the introduction of the trunk cable into the insulation protection cover 4, which will be described later. In this way, even if the cut 7 reaches the cable insertion hole 4b, it does not reach the branch cable penetration part, thereby maintaining the connection of the branch cable 2 to the insulating cover 4,
It also maintains the watertightness of the penetrating portion.

Now, the insulation protection cover 4 constructed as described above is carried to the installation site together with the main cable 1 to be installed, and is subjected to branch connection processing.

FIG. 3 shows the structure of a branch connection constructed using the above-mentioned insulating cover 4. The insulating protection cover 4 is expanded from the cutout 7 and is wrapped around the main cable 1. At this time, the trunk cable 1 is positioned so as to be inserted through the cable insertion holes 4b, 4b. The main cable 1 thus taken in has its insulation coating and sheath removed by stripping steps at the part where it passes through the storage chamber 4a to expose the conductor, and this exposed conductor part is integrally connected to the insulation cover 4. The conductor at the connecting terminal 2a of the branch cable taken into the branched cable through the penetrated portion is attached thereto, and these are fastened by compression of the sleeve 8 to form a predetermined conductor connecting portion. With this conductor connection part stored in the storage chamber 4a, the remaining gap in the insulating cover 4 is filled with waterproof compound 9, and then the mating surface at the cutout 7, the cable insertion hole 4b, and the trunk cable 1 are filled. The boundary between the two is welded by a welding member 6, thereby forming an insulation-protected branch connection.

In addition, it is desirable to join the mating surfaces other than the welded part in the cut 7 with adhesive,
Further, a waterproof tape may be wrapped around the outer surface of the insulation protection cover 4.

[Effects of the invention] According to the branch connection section of the present invention configured as described above, when making a branch connection at a cable installation site, it is possible to not only ensure waterproofness but also to maintain the integrity of the main cable. The branch cable, which is smaller in size compared to that of the previous model, is joined to the insulation protective cover in a completely integrated state based on the joining obtained by molding, and then taken into the interior through the penetration part in the joined integrated state. Since the terminal section is branched and connected to the main cable,
Even if tension is applied to the branch cable from the outside, the tension at the branch connection part between the trunk cable and the branch cable is significantly reduced, and therefore, the breakage of the branch cable, which becomes noticeable due to the diameter reduction, is greatly reduced. Furthermore, it is possible to obtain stable mechanical properties, and it has great practical value.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing an example of a prefabricated cable with a branch, Figs. 2 and 3 show an example of the branch connection part of the cable according to the present invention, and Fig. 2 is an insulated protective cover with a branch cable. FIG. 3 is a cross-sectional explanatory view of a branch connection section constructed using the same insulation protection cover. Explanation of symbols: 1 is the trunk cable, 2 is the branch cable, 4 is the insulation protection cover, 7 is the cutout, 8
is a sleeve for connecting conductors.

Claims (1)

[Scope of utility model registration request] In the branch connection section, which is constructed by covering the branch connection part between the main cable and the branch cable with a pre-formed insulation protection cover, the insulation protection cover is molded from resin, which is its own constituent material, and the branch connection part is formed by covering the branch connection part between the trunk cable and the branch cable. The cable is integrally joined on the circumference of the cable to allow the branch cable to pass through it, and the insulation protection cover is provided with a cut that does not reach the part where the branch cable passes through, and the cable is inserted into the insulation protection cover through this cut. A cable branch connection section characterized in that a main cable connected to the main cable and a terminal of a branch cable led out into the main cable through the insulating protection cover penetration part are connected to each other.