JPH0133916B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cable branch mold connection method.

2. Description of the Related Art Trunk cables used for indoor wiring in high-rise buildings such as buildings and condominiums are single-core twisted cables in which several (usually three) insulated wires are twisted together.

In such a single-core twisted type trunk cable,
Normally, each branch line to be led to each floor of a building is connected to each main line with a conductor in advance in the factory, the conductor connection part is molded and insulated, and the line is transported and extended in the form of a main line cable with branch lines. .

By the way, as a branch mold connection method for a single-core twisted type cable, each core of a single-core twisted type cable in which branch lines are electrically connected is arranged in parallel rows at a predetermined interval from each other, and these branch connections are A connection method is known in which the periphery is integrally molded with a rubber or plastic insulating material.

However, in the above connection method, a troublesome work of separating the wire cores is required to make each wire core parallel to each other, and this work is extremely difficult, especially in the case of a large-sized cable. In addition, since the above connection part has a structure in which the cores are arranged in parallel, the outer diameter of the connection part is inevitably large, making it difficult to install a single-core twisted type cable with such a connection part vertically in a high-rise building, etc. In this case, there is also the problem that the floor through hole through which the cable is inserted must be made large.

The cable branch mold connection method according to the present invention is a method that can solve the above-mentioned difficulties, and is a method that can solve the above-mentioned difficulties, and uses a branch connection part in which a branch line is conductor-connected to each main line of a main line cable in which a large number of main line electric wires are twisted together. In the method of casting and molding rubber or plastic material by placing the trunk in a half-split mold, the branch connections in each main line are shifted in the longitudinal direction so that the branch connections do not come into contact with each other, and the main lines are twisted. The main line,
A cross section in which a large number of wire insertion holes for individually inserting branch wires are provided in a concentric arrangement, and each of these wire insertion holes is divided into two parts vertically by dividing lines parallel to each other. The present invention is characterized in that circular blocks are respectively fitted to support the main lines and branch lines, and then a rubber/plastic insulating material is injected into the mold to insulate the branch connections.

The present invention will be explained below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the branch mold connection method according to the present invention. In the figure, 1 is a trunk cable made by twisting a large number of trunk wires, and the one shown is three trunk wires. A so-called triplex type cross-linked polyethylene insulated vinyl sheath cable (CVT cable) in which 2, 2, 2 are twisted at a predetermined pitch.
It shows. 3, 3... are both insulated branch wires that are branched and connected via conductor sustaining sleeves 4 at predetermined short intervals of each main line 2, for example every 3 to 5 m (floor height of a building). In the illustration, two branch lines 3, 3 for one main line 2 are taken out from the sleeve 4 toward both left and right sides. Reference numeral 5 denotes a cylindrical mold with a spindle-shaped cavity 51 and a vertically split cylindrical mold, and a ring-shaped groove 52 is formed on the inner wall of both ends.
is formed. 53 and 54 are a resin injection hole and an air vent hole provided in the cylindrical mold 5, respectively. Reference numeral 6 denotes a rubber/plastic insulating material, such as vinyl chloride resin, for mold-insulating the branch connection portion S.

Reference numeral 7 denotes a metal block having a circular cross section that protrudes and is fixed to the inner walls of both ends of the mold 5, and the block 7 is connected to the main lines 2, . . . as shown in FIGS. 2A, B and C. and through holes 71 for individually and hermetically inserting and supporting the branch wires 3, .
. . . and 72, . . . are arranged concentrically with respect to the circular cross section. In the illustration, the main line holes and the branch line holes are arranged so as to be located on a concentric circle _C1 and a concentric circle _C2 , respectively. In this case, each trunk line insertion hole 7
1, 71, 71 and each branch line insertion hole 72, 7
2 and 72 are preferably provided in a triangular arrangement from the viewpoint of structure and electrical characteristics. 73
are dividing surfaces that divide each of the insertion holes 71, . . . , 72, . . . into upper and lower halves, and each dividing surface 73, .
... are arranged parallel to each other. 7
Reference numeral 4 denotes a ring-shaped projection provided on the outer periphery of one end of the block 7, and the ring-shaped projection 2 has a shape that fits into the ring-shaped groove 52 in the mold 5. 7
Reference numeral 5 designates a rectangular flange portion formed at the other end of the block 7, and pin fitting holes 76 are provided at both ends thereof in a direction perpendicular to the dividing surface 73, and the dividing piece 7a divided at the dividing line 73 ,7b,7c,7
A lock pin 8 is fitted to mechanically integrate d and 7e. 9 is the above-mentioned divided piece 7a, 7b, 7
This is an auxiliary band that holds c, 7d, and 7e all at once.

Next, to explain the procedure of the branch mold connection method of the present invention, first, the branch connection parts S, S, S in each main line 2, 2, 2 are provided so as to be shifted from each other in the longitudinal direction as shown in FIG. Avoid electrical contact between branch connections. In this case, each branch connection portion S is arranged so that the trunk cable 1 is in a twisted state. Next, the branch connection part S is accommodated in the mold 5, and each trunk line 2 and each branch line at both ends of the branch connection part S are connected by circular blocks 7, 7 fitted into both end walls of the mold 5. 3 is firmly inserted and supported. Thereafter, a vinyl chloride resin compound 6 is filled into the mold 5 through the resin injection hole 53 of the mold 5 using an extruder, an injection molding machine, etc., thereby obtaining a desired molded insulated branch connection.

As described above, in the branch mold connection method according to the present invention, the branch line connections in each main line of a main line cable in which a large number of main line electric wires are twisted are shifted from each other in the longitudinal direction, and the branch connection parts are connected in a non-contact manner. Since the main cables are arranged in a twisted state and then subjected to a batch mold insulation treatment, the overall shape of the molded branch connection can be further downsized, and the above-mentioned conventional difficulties can be eliminated. Moreover, since the branch connection parts are shifted from each other in the longitudinal direction, electrical contact between the branch connection parts can be completely interrupted, so that a connection part with stable electrical characteristics can be obtained.

Furthermore, in the present invention, a large number of wire insertion holes are provided in a concentric arrangement at both ends of the mold for inserting and supporting main lines and branch wires individually, and each of these wire through holes is divided into upper and lower halves. Because the block has a circular cross section divided by parallel dividing lines, the wires inserted into the mold can be compactly inserted into the mold in a predetermined twisted state and in a completely sealed state. It can be supported, and regardless of the rotational phase of the block based on the twisting of the main cable when the block is attached to the cable end, the outer periphery of the block is circular, so the block and two-split cylindrical mold can be It has the advantage that a reliable fit can be guaranteed, and the connection part can be easily molded despite the twisting of the main cable. Of course, since the block is divided, it is easy to separate it after molding.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the cable branch mold connection method according to the present invention, Fig. 2A is a partially cutaway side view of a block with a circular cross section used in the present invention, and Fig. 2B is Fig. 2A. A-A line arrow view, 2nd
Figure C is a sectional view taken along the Ro-Ro line in Figure 2A. In the figure, 1 is a main cable, 2, 2 is a main line, 3, 3 is a branch line, 5 is a two-piece cylindrical mold, 6 is a rubber/plastic insulating material, 7 is a block with a circular cross section, 71 and 72 are wire insertion holes, 7
3 is a dividing surface, and S is a branch connection part.

Claims (1)

[Claims] 1. A method in which a branch connection section in which a branch line is conductor-connected to each main line of a main line cable made up of a number of twisted main line electric wires is housed in a half-split mold and cast-molded with rubber or plastic material, The branch connections in each of the main lines are shifted in the longitudinal direction so that the branch connections do not come into contact with each other, and are arranged so that the main lines are in a twisted state, and then housed in a half-split mold. A large number of wire insertion holes for individually inserting the main line and the branch line are provided in a concentric arrangement at both ends of the mold,
Each of the wire insertion holes is divided vertically into two by parallel dividing lines, and a block having a circular cross section is fitted into each hole to insert and support each of the main wires and branch wires, and then, A cable branch mold connection method characterized by injecting rubber or plastic insulating material into a mold to insulate the branch connection part.