JPH03230717A - Three-way branch pipe for power cable - Google Patents

Abstract

PURPOSE:To maintain required moisture-proof and insulating characteristics while the size of a branching part is reduced by a method wherein protruding cross-section rings are applied along the circumferences of the winding-start positions of insulating tapes on the surfaces of respective branch cylinders. CONSTITUTION:Protruding cross-section rings 14 and 15 are solidly applied along the circumferential surfaces of the predetermined winding-start positions of respective protective insulating tapes 13 on a large cylinder part 11 and branch cylinders 12a, 12b and 12c. After a three-way branch pipe 10 is applied to a power cable, the protective insulating tapes 13 are wound on the outer surface of the cable on the lower side of the protruding cross-section ring 14 of the large cylinder part 11 and on the outer surfaces of the respective single cable cores on the upper sides of the protruding rings 15 of the branch cylinders 12a, 12b and 12c to complete fixation and insulation reinforcement of the three- way branch pipe 10 on the power cable. With this constitution, the required winding regions can be realized only by applying the protruding cross-section rings 14 and 15 to the edge parts of the wound tapes.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a three-pronged branch pipe for power cables used for branching each single-core cable at the terminal end of a three-phase cable cable, etc. be.

[Prior Art] Conventionally, in three-phase cable cables, three-pronged branch pipes are often installed at the connection portions, termination portions, etc., in order to safely and reliably branch the m; cables. As shown in FIG. 7(a), Ibl, the most commonly used three-pronged branch pipe 1 has a large cylindrical part 2 into which the three-phase capeple is inserted together with the exterior part, and a three-pronged branch pipe 1 in which the upper part of this large cylindrical part 2 is inserted. It consists of three branch pipes 3a, 3b, and 3c that branch into three branches, and each single-core cable is inserted through each of the branch pipes 3a, 3b, and 3c.

As shown in Fig. 8, the cable end portion into which this three-pronged branch pipe l is inserted is removed from the exterior portion 4 of the power cable, and the
The cable is branched into strips of single-core cables 5a, 5b, and 5c, and the above-mentioned three-pronged branch pipe 1 is inserted into the base of the branch. At this time, protective insulating tape is applied to the outer periphery near both ends of the three-pronged branch pipe 1, from the large cylinder part 2 to the exterior part 4, and from the branch pipes 3a, 3b, 3c to the single-core cables 5a, 5b, 5c. 6 is wound, the seam is waterproof and fixed, and m8
Insulation reinforcement is provided on the cables 5a, 5b, and 5C sides. In this case, each tun core cable 5a, 5b, 5c
In some cases, the grounding wire 7 is extended from the shielding layer.

[Problem to be solved by the invention 1 In this way, the fixing of the three-pronged branch pipe l to the power cable is as follows:
This is done by winding a protective insulating tape 6 around the outer periphery from both ends of the three-pronged branch pipe 1 to the exterior part 4 and the single-core cable, respectively. When winding this insulating tape 6, it is necessary to set the winding start position of one example of a three-pronged branch pipe at a predetermined position in order to maintain the same waterproof and insulating properties. It is extremely troublesome to work while measuring, and there is a great risk of incorrect work. In particular, three-pronged branch pipe 1
When downsizing the three-pronged branch pipe 1, if the winding start position is incorrect, the relative error will increase and there is a risk of having a serious impact on the waterproof and insulation properties. This is an impediment to miniaturization of the terminal and connection structures of power cables.

An object of the present invention is to solve the above-mentioned problems and to easily determine the predetermined winding end position without error when winding an insulating tape, thereby achieving a predetermined waterproofing even when miniaturized.・An object of the present invention is to provide a three-pronged branch pipe for power cables that can maintain insulation properties.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the three-prong branch pipe for power cables according to the present invention includes a large tube portion into which a three-core cable is inserted, and each branch pipe into which the three-core cable is branched. An electric cable that has three branch tubes through which single-core cables are inserted, and is fixed by wrapping an insulating tape between the large tube portion and each branch tube with a predetermined cable inserted between the cables. The present invention is also a branch pipe, characterized in that a protruding ring is provided around the large tube portion and each branch tube at the winding end position of the insulating tape on the surface of the large tube portion and each branch tube.

[Function] In the three-pronged branch pipe for power cables having the above-described configuration, the protrusion provided around the branch pipe indicates the predetermined winding end position of the insulating tape.

[Embodiment 1] The present invention will be explained in detail in Section 8 based on the embodiment illustrated in FIGS. 1 to 6. Note that the same reference numerals as in the conventional example indicate the same members.

FIG. 1 shows a connecting portion of an electric cable for driving, for example, a three-phase high-voltage motor, and FIG. 2 shows a sectional view of the connecting portion as seen from the side. The outer sheath 4 at the terminal end of the electric cable is removed and branched into three single-core cables 5a, 5b, and 5C, and a three-pronged branch pipe made of striped chloroprene rubber, ethylene propylene rubber, etc. is attached to the base of the branch. 10 is attached. As shown in FIGS. 3 and 4, this three-pronged branch pipe IO has a large cylindrical portion 11 into which a three-phase capeple is inserted from below together with the exterior portion 4, and three pipes that branch into three prongs at the upper part of this large cylindrical portion 11. It consists of branch tubes 12a, 12b, 12c, and the lower end open portion of the large tube portion 11 and each branch tube 12a, 12b,
Both of the lower end open parts 12c are molded so that the wall of the cylinder at the tip is thin. Then, cable portion 1 branch portions 12a, 12b, 12 which are not branched into the large cylinder portion 11 are provided.
The branched single-core cables 5a, 5b, and 5c are inserted through C, respectively, and the protective insulating tape 13 of each of the large tube portion 11 and the branch tubes 12a, L2b, and 12c is at a predetermined starting position. Convex ring 14 on the outer peripheral surface
．． 15 are integrally provided around the circumference.

The three-pronged branch pipe 10 is fixed to the power cable and the insulation reinforced by attaching the three-pronged branch pipe 10 to the power cable, and then applying the protective insulating tape 13 from the convex ring 14 of the large cylindrical part 11 to the cable sheathing part 4 on the lower side. and branch tube 12a
, 12b, 12C from the convex ring 15 to each of the upper single core cables 5a, 5b, 5C. In addition, when winding, the predetermined winding range can be achieved by simply using the convex rings 14 and 15 as the ends of the winding, and there is less risk of incorrect work. The total length of 50m
Even when configured as small as about m, predetermined waterproof and insulation properties can be easily obtained.

Furthermore, in FIGS. 1 and 2, the tip of each single-core cable 5a, 5b, and 5C branched by the three-pronged branch pipe 10 is made of ethylene propylene rubber or the like, and has a length of about 70 mm, for example. A hollow spindle-shaped rubber stress cone 20 is inserted into each. These stress cones 20 are connected to single-core cables 5a, as shown in FIG.
5b and 5c, and includes a rubber insulating part 22 and a semiconductive layer part 23, and the rubber insulating part 2
For example, three protruding rings 24 are integrally provided around the outer circumferential surface of the large diameter portion 2 at equal intervals. Each stress cone 2 is placed on the flat part between the convex rings 24 for later phase determination.
Colored tapes made of synthetic resin materials of different colors, for example, red, blue, and white, can be wound for each color, and the height of the convex ring 24 is made approximately equal to the thickness of the wound colored tape. There is. And these stress cones 2
Recesses 25 and 26 for winding the protective insulating tape are formed on the outer periphery near both ends of the 0.

Here, as shown in FIGS. 1 and 2, the semiconducting layer portion 23
is each outer semiconducting layer 31 of the single-core cables 5a, 5b, and 5c.
A protective insulating tape 13 for fixing the three-pronged branch pipe l is connected to the recess 25 at the lower end of the stress cone 20 from the branch pipes 12a, 12b, and 12c. The stress cones 20 are continuously wound to the position shown by the dotted line in FIG. Fixed. On the other hand, a conductor 33 is exposed at the end of each single-core cable 5a, 5b, 5c, and a motor-side lead wire 35a of a high-voltage motor (not shown) is connected via a connection terminal 34.
, 35b, and 35c, and an insulating tape 36 is wound thereon.

With such a configuration, the single-core cable 5a,
Since the stress cone 20 is inserted into 5b and 5c,
The main purpose of the stress cone 20 is to alleviate electrical stress.
0 into the single-core cables 5a, 5b, and 5c, the protruding ring 24 reduces slippage and improves workability during insertion. 13.13'' can satisfy the insulation properties without counting the number of turns by simply filling the concave portions 25.26, and can obtain a smooth shape without being raised as a stepped portion.

Note that instead of the above-mentioned three-pronged branch pipe 10, a three-pronged branch pipe 10° as shown in FIG. 5 may be used.

In this three-pronged branch pipe 10°, the convex ring 14.1
On the outside of 5, separate protruding rings 16,17 are arranged parallel to the protruding rings 14,15. In this case, if the insulating tape 13 is wound with the protruding rings 14 and 15 as the winding start positions, the protruding rings 16 and 17 will be buried in the insulating tape 13. Convex ring 1
6.17 acts to stop the movement of the insulating tape 13, and effectively prevents misalignment between the wound insulating tape 13 and the large cylinder portion 11 and the branch tubes 2a, 12b, 12c. The large cylinder part 11 and the branch cylinder 1 were prevented from slipping by surface friction of the insulating tape 13 which was crimped and wound.
2a, 12b, and 12c can reduce the area of their outer peripheral surfaces. Therefore, in the above-mentioned three-pronged branch pipe 10, it is possible to further shorten the overall length of the large cylinder portion 11, the branch pipes 12a, 12b, 12c, and ultimately the three-pronged branch pipe 10'.

In addition, in the above-mentioned embodiment, the convex rings 14, 15.
16.17 is the large cylinder part 11. Branch tube 12a, L2b, 12
Although it is preferable to provide it over the entire circumference of c, there is no problem even if it is provided partially.

[Effects of the Invention] As explained above, the three-pronged branch pipe for power cables according to the present invention can easily set the predetermined winding start position without error when winding the insulating tape due to the protruding ring provided around the circumference. This makes it easy to wind the windings while maintaining the specified waterproof and insulating properties, and even when downsizing, it is possible to maintain good waterproof and insulating properties in the same part of the winding, making it possible to maintain good waterproof and insulating properties for branch pipes and even power cables. It becomes easy to downsize the terminal section and the connecting section.

[Brief explanation of drawings]

1 to 6 show an embodiment of the three-pronged branch pipe for power cables according to the present invention, FIG. 1 is a front view of the terminal part of the power cable, FIG. 2 is a sectional view seen from the side, Section 3 is a front view of a three-pronged branch pipe, Fig. 4 is a plan view, Fig. 5 is a front view of a three-pronged branch pipe according to another embodiment, Fig. 6 is a cross-sectional view of a stress cone, and Fig. 7 ( at is a plan view of a conventional three-pronged branch pipe, fbl is a front view, and Fig. 8 is a front view of a conventional power cable terminal part. Reference numeral 4 is an exterior part of the power cable, 5a, 5b, and 5C are sheep core cables. 10. 10° is the three-pronged branch pipe, 11 is the large cylinder part,
12a, 12b, and 12c are branch tubes, 13.13° is an insulating tape, 14.15.16.17 is a convex ring, and 20 is a stress cone.

Claims (1)

[Claims] 1. It has a large tube portion into which a three-core cable is inserted, and three branch tubes through which each single-core cable branched from the three-core cable is inserted, and a predetermined cable is inserted into the large tube portion and each branch tube, respectively. A three-pronged branch pipe for a power cable in which an insulating tape is wound and fixed between the cable and the cable in the above-mentioned state, and the large cylinder part and each branch pipe have a winding end position of the insulating tape on the surface of each branch pipe. A three-pronged branch pipe for power cables characterized by having a convex ring around the circumference.