JPS61292815A - Branch formation of cable with branch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for molding a branch part of a cable with a branch, particularly a cable with a branch having a thin branch line.

[Conventional technology and its problems]

For lighting equipment in tunnels, elevated roads, etc., as shown in Fig. 5, a branch line 15 is branched from the main cable 11 and energized to the lighting equipment H, but the branch part 3 is waterproof and durable. In view of the above, the insulating reinforcing layer is formed by molding an insulating resin composition.

As shown in FIG. 3, this insulation reinforcing layer is formed by stripping off the jacket 32 and insulator 33 of the main cable 31, and then stripping off the insulation coating 36 of the branch line 35 to expose the exposed conductor 34. The conductors 37 that have been connected to each other are fixedly connected using the crimp connection sleeve 38, and then the main cable 31 and the branch line 35 are supported and fixed to the mold m, and the connection part a of both conductors 34 and 37 is
The insulating resin composition P is injected into the mold m from the injection port i and molded.

When injecting the resin composition P in this molding, conventionally, as shown in the same figure, the conductor 37 comes out of the crimp connection sleeve 38 and goes straight to the insulating coated branch line 35.
A main cable 31 and a branch line 35 are supported and fixed to a mold m.

Therefore, when the resin composition P is injected into the mold m from the injection port i, the resin flows in both directions of the mold m, that is, in the direction of the arrow in the figure, and tension in the flow direction is applied to the main cable 31 and the branch line 35. However, if the conductor 37 is straight as described above, the tension will be concentrated at the point where the conductor 34 is led out from the connection sleeve 38.

Here, if the branch line 35 is relatively thick, even if tension is applied to the branch part, the tensile strength of the branch line itself is large, so there is no risk of it breaking at the branch part a, but 2-(7 lines/0.6 t
ax), there is a serious problem that the branch wire 35 of the branch connection portion 1 may be disconnected due to the molding pressure.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide a molding method for a branch part in which the branch conductor is not disconnected at the branch part even when the branch line is relatively thin. It is something.

[Means to achieve the purpose]

In order to achieve the above object, in the above conventional forming method, the branch line from the fixed connection part is provided with a loose part.
By forming slack portions, the main cable and branch cables are supported and fixed in the mold, and the connecting portions of both grooves are loaded.

[Effect]

In the molding method configured in this manner, as described above, when tension is applied to the main cable and the branch line by injecting the insulating resin composition, the slack portions are stretched by the tension to absorb the tension. Therefore, no tension is applied to the fixed connection portion (branch connection portion), and there is no risk of disconnection of the conductor.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Embodiment 1] In the embodiment shown in FIGS. 1 and 4, the main cable 11 is a single-phase three-wire cable, and the branch cable (branch line) 15 is a ground wire e.
As shown in FIG. 1, first, the insulator 13 of the outer sheath of the trunk cable 11 (crosslinked polyethylene insulated vinyl sheath cable (CV) 22nd x 3 cores) is sequentially peeled off to expose the conductor 14. On the other hand, branch cable 15 (cross-linked polyethylene insulated vinyl sheath cable)
The terminal of the (CV) 2d x 3 cores is also sequentially stripped off its jacket IS and insulator 16 to expose the conductor 17. The conductor 17 of this branch cable 15 is connected to the conductor 1 of the main cable 11.
4, and crimped the - part with a connecting sleeve 1 to firmly connect both groove bodies 14 and 17.

Note that e in the figure is a ground wire.

Next, as shown in FIG. 1, the branch cable 15 is made a U-turn to form a slack part 19, and the main cable 11 and the branch cable 15 are supported and fixed to the gold fim, and both groove bodies 14 and 17 are connected. Loaded with part 1, injection capacity 400 c
Using the injection molding machine shown in c, the insulating resin composition P was injected into the mold m at the injection port i at an injection resin temperature of 175°C, an injection resin amount of 240 cc, an injection time of 8 sec%, and an injection pressure of 31/ffl.
After injection, the spot cooler was used for 30 seconds.
After cooling for a period of c, the insulation reinforcing layer of the branch part 3 is molded,
A branched cable A shown in FIG. 4 is obtained.

When resin is injected in this molding, when tension is applied to the main cable 11 and branch cable 15 due to the injection, the U-turned slack portion 19 stretches due to the tension and absorbs the tension.

This cable A with a branch is used, for example, as shown in FIG. 1, it is connected to the ground main line E laid parallel to the main cable 11.21.

(Embodiment 2) In the embodiment shown in FIG. 2, a branch cable (branch line) 25 with a ground wire e is connected to the single-phase three-wire trunk cable 21 shown in FIG. 4, as in the previous embodiment. And, first,
As shown in Figure 2, trunk cable 21 (cross-linked polyethylene insulated vinyl sheath cable (CV) 14-X3 core)
The outer jacket 22 and insulator 23 of the main cable 21 are sequentially peeled off to expose the conductor 24 of the main cable 21. On the other hand, branch cable 25
(Cross-linked polyethylene insulation vinyl di-scale (
The outer sheath 2S and the insulator 26 of the terminal of the (CV) 2md x 3 cores are sequentially peeled off to expose the conductor 27. The conductor 27 of this branch cable 25 is crimped and connected to the exposed conductor 24 of the main cable 21 using a connecting sleeve 28 .

Next, as shown in the figure, the one-branch cable 25 is loop-turned to form a slack part 29, and the main cable 21 and branch cable 25 are supported and fixed to the mold m, and both groove bodies 24 and 27 are connected. Even in the molding of the part 3, when tension is applied to the main cable 21 and the branch cable 25 by resin injection, the loop-turned slack portion 29 is stretched by the tension (the diameter is reduced) to absorb the tension.

This branched cable A is also used as shown in FIG.

In addition, in Examples 1 and 2 above, the insulated core wire of the branch cable is U-turned or loop-turned to form the slack part, but it is not necessarily necessary to make this shape, and the branch cable is formed by the flow of resin during molding. Any loose shape that can be stretched (moved) may be used.

[Comparative example]

In order to confirm the effect of the present invention, based on the conventional method shown in FIG. Same molding material, injection resin temperature 160℃, injection resin amount 240cc, injection time 6 seconds, injection pressure 40
KIF/d, cooling time (spot cooler) 25 Q
The branch part 1 was molded under SeC conditions.

After this molding, the branch part λ was dismantled and the presence or absence of breakage at the branch connection part was examined. As a result, 6 out of 10 were found to be broken or a part of the stranded wire forming the conductor was broken.

On the other hand, in Examples 1 and 2, all 10 wires were not disconnected at all.

〔effect〕

As explained above, according to the present invention, even when the size of the branch cable is thin, injection molding conditions can be slightly changed (
It is possible to provide a high-quality branch connection without disconnection only by forming a slack part).

[Brief explanation of the drawing]

1 and 2 are plan views of each embodiment of the present invention when the branch part is loaded into a mold, FIG. 3 is a plan view of the conventional example, and FIG. 4 is a plan view of the conventional example. FIG. 5 is a cross-sectional view of the main parts of the branch cable manufactured by the molding method and is a wiring diagram, and the main symbols in the figure are as follows. 11.21... Trunk cable, 12.22... Sheath, 13.23... Insulator, 14.24... Conductor, 1
5゜25...Branch cable, 16, 26...Insulator, 18.28...Connection sleeve, m...Mold patent applicant Tuck Electric Cable Co., Ltd. Agent Kama 1) Text 2nd 1 Figure 112131... 142434... Figure 3 152535... 14.24 Figure 2 #111 (Jig 1V f-4 mold Figure 5 Procedure amendment (8 buttons September 12, 1985)

Claims (3)

[Claims] (1) Strip off the jacket and insulation of the main cable, firmly connect the exposed conductor to the exposed conductor by stripping off the insulation coating of the branch line, and connect the slack part to the branch line from the connection point. The main cable and the branch line are supported and fixed in a mold, the connection part of both conductors is loaded, and an insulating resin composition is injected into the mold to mold an insulating reinforcing layer of the branch connection part. A method for forming a branch part of a cable with a branch. (2) The method for forming a branch part of a cable with a branch according to claim (1), wherein the slack part is formed by making a U-turn. (3) The method for forming a branch part of a cable with a branch according to claim (1), wherein the slack part is formed by loop turning.