JP2003087955A - Joint type branched cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint type branched cable capable of monitoring deterioration in each section between junction sections at the time of regular inspection or the like, or always monitoring shielding layer current or voltage for each section between the junction sections, capable of early confirmation of an accident point in case of abnormality, and diagnosing deterioration of a single body of the joint section, that is, checking electrical performance. SOLUTION: An end section of a semiconductive rubber layer 50 positioned inside an insulation tube 35 is overlapped by a prescribed length (ΔL) from an end of hardware 36 is extended in the lengthwise direction of the cable. A prescribed radial clearance (ΔR) is maintained between the hardware 36 and the end of the semiconductive rubber layer 50. A connector box A of cable shielding layer 3 is formed in the insulation tube 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a joint type branch cable installed on a shaft as a power supply facility in a building.

[0002]

2. Description of the Related Art For example, in order to supply electric power to each floor inside a building, a cable with a branch installed vertically through each floor of the building is used.

The applicant of the present patent application has filed Japanese Patent Application Laid-Open No. 5-244715
As disclosed in the publication, a joint-type branch cable with a T-branch connection unit removably inserted in series in the middle of the main cable along the longitudinal direction is proposed.
The structure of this joint-type branched cable will be briefly described with reference to FIGS. 3 to 5.

That is, the joint-type branch cable 1a
Is a trunk cable 10 having a plug-in terminal 30,
A T-branch connection unit 40 and a branch cable 20 are provided.

In the main cable 10, the male terminal 31 is attached to the conductor 5 exposed by the stepped removal of the shielding layer 3 and the insulator 4 of the main cable 10.

The T-branch connecting unit 40 has a structure in which a T-branching female terminal 42 is arranged inside and protected by a unit insulating cylinder 43.

T-branch connection unit 40 and main cable 1
The 0 plug-in terminal 30 is electrically connected by fitting the male terminal 31 into the T-branching female terminal 42.

Further, the connection fittings 32 provided on the outer periphery of the end of the plug-in terminal 30 are screwed into the male screw portions 41 provided at both ends of the T-branch connecting unit 40, whereby the main cable 10 and the T-branch connecting unit 40 are connected. Mechanical connection is made.

By tightening the connection fitting 32, the tapered insulating portion 33 at the tip of the plug-in terminal 30 of the main cable 10 is pressed against the inner wall of the T-branch connecting unit 40.

The T-branch connecting unit 40 has a branch portion 44 in the horizontal direction. The branch cable 20 includes the shielding layer 11
After the conductor 12 is exposed by stepping off the insulator 12 and the conductor 13, the male terminal 14 integrally formed in an L-shape and the conductor 13 are connected by a compression sleeve 15 and insulated and protected by a branch insulating cylinder 16. It The male terminal 14 is fitted into the T-branch female terminal 42 housed inside the branch portion 44, and the conductors of the branch cable 20 and the main cable 10 are electrically connected. The branch cable 20 is fixed to the T-branch connection unit 40 with a hose band (not shown) while being fitted to the branch portion 44.

In the joint-type branch cable 1a having the above structure, the trunk cable 10 is detachably electrically connected via the T-branch connecting unit 40, and by disconnecting these connections, the trunk cable 10 is divided into a plurality of pieces in the longitudinal direction. It is divided into parts. Therefore, there is an advantage that the weight is reduced, the transportation, the winding on the drum, the laying work are facilitated, and when an accident occurs, the accident part can be easily removed or replaced.

[0012]

However, the shield system of the joint type branch cable 1a, including the trunk cable 10 and the branch cable 20 connected by the T branch connection unit 40, is electrically connected continuously. It is in the connected state.

That is, as shown in FIG. 5, the trunk cable 10 has an insulating tube 35 which forms an insulating layer around the spacer 34 made of insulating EP rubber on the outer periphery of the insulator 4 of the terminal-treated cable 10. Is formed. On the outer circumference of the insulating cylinder 35, a fixing metal fitting 3 for attaching the connecting metal fitting 32.
6 is integrally molded and attached to the insulating cylinder 35.

On the cable shielding layer 3 adjacent to the terminal-treated cable insulator 4, a tinned wire 37 is used to connect the ground wire 3
One end of 8 is wound, and the other end of the ground wire 38 is led out to the outside. A semiconductive tape 39 is wound around the metal fitting 36 and the insulating cylinder 35 to the cable shielding layer 3 on the outer periphery thereof. Further, an insulating tape 51 and a heat shrinkable tape 52 are coated on the outer periphery thereof.

The branch cable 20 is also the above trunk cable 1
The structure is the same as that of 0, and the ground wires 38 from each trunk cable 10 and the branch cable 20 are connected to each other as shown in FIG.

As described above, in the joint type branched cable 1a having the above structure, even if the ground wires 38 from the main cable 10 and the branch cable 20 are electrically separated from each other, the T branch connection unit 40 is used. In the connected main cable 10 and branch cable 20, the cable shielding layer 3 is in a state of being electrically connected to each other through the semiconductive tape 39, the fixing metal fitting 36, the connecting metal fitting 32, and the like. Therefore, the conventional joint-type branch-attached cable 1a has a problem that the T-branch connecting unit 40 cannot perform the deterioration diagnosis for each section between the connecting portions, and the insulation deterioration diagnosis cannot be performed unless they are collectively performed.

Therefore, an object of the present invention is to enable deterioration diagnosis for each section between connecting portions at the time of periodic inspection, or to constantly monitor the shielding layer current or voltage for each section between connecting portions. The purpose of the present invention is to provide a joint type branching cable that enables early confirmation of the accident point and can also perform deterioration diagnosis of the connection unit itself, that is, electrical performance check.

Another object of the present invention is to provide a joint type cable with a branch, which is capable of diagnosing the deterioration of the branch cable or constantly monitoring it.

[0019]

The above object is achieved by a joint type branch cable according to the present invention. In summary, the present invention comprises a T-branch connection unit for detachably electrically connecting a trunk cable in series in the longitudinal direction and detachably electrically connecting one end of a branch cable branched from the middle of the trunk cable. In the joint-type branched cable, the trunk cable has an insulating tube on a cable insulator that has been subjected to terminal treatment, and an outer periphery of the insulating tube,
Arranging a metal fitting for the T-branch connection unit,
A semiconductive rubber layer extending along the longitudinal direction of the cable from the outer peripheral portion of the cable insulator adjacent to one end of the insulating cylinder to the inside of the insulating cylinder is provided inside the insulating cylinder. The end of the semiconductive rubber layer overlaps with the end of the metal fitting in the longitudinal direction of the cable, and
Between the metal fitting and the end of the semi-conductive rubber layer, the pieces are held apart from each other in the radial direction, and the edge portion of the cable shielding layer is formed in the insulating cylinder. It is a cable.

According to one embodiment of the present invention, a semi-conductive tape is wound between the semi-conductive rubber layer located on the outer periphery of the cable insulator and the cable shielding layer adjacent to the cable insulator.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The joint-type branch cable according to the present invention will be described below in more detail with reference to the drawings.

FIG. 1 and FIG. 2 show an embodiment of a joint type branch cable according to the present invention. In the joint-type branch cable 1 of the present invention, the main cable 10 and the branch cable 20 connected by the T-branch connection unit 40 are in a state where the cable shielding layer 3 is cut off and electrically separated for each connection section. It is said that

According to this embodiment, as shown in FIG. 1, the main cable 10 is the conventional main cable 10 shown in FIG.
The structure is the same as the above, except that the cable shielding layer edge cutout A is formed inside the cable insulating cylinder 35.

That is, according to this embodiment, the semiconductive rubber layer 50 is provided extending from one end of the insulating tube 35 forming the cable insulating layer into the insulating tube 35 along the longitudinal direction of the cable. To be One end of the semiconductive rubber layer 50 extends from the end of the insulating cylinder 35 to the insulating spacer 34,
On the other hand, the end of the semi-conductive rubber layer 50 inside the insulating cylinder has a predetermined distance (Δ) from the end of the fixing bracket 36 in the longitudinal direction of the cable.
Only L) is extended to the metal fitting side. Also, the fixing bracket 3
A separation distance (ΔR) in the radial direction is held between 6 and the semiconductive rubber layer 50 even at the closest position. In this embodiment, the distances ΔL and ΔR are 1 to
It is set to 20 mm and 1 mm or more.

A semi-conductive rubber layer 50 on the insulating spacer 34
A semiconductive tape 39 is wound between the cable insulation layer 4 and the cable shielding layer 3 adjacent to the cable insulator 4. A ground wire 38 is fixed to the cable shielding layer 3 by a tin-plated wire 37 as in the conventional case. The end of the ground wire 38, the semi-conductive tape 39, the cable insulating tube 35, and the fixing bracket 3
An insulating tape 51 is wound so as to cover the outer periphery of 6, and the outer periphery thereof is covered with a heat shrink tape 52.

Joint type branch cable 1 having the above structure
As shown in FIG. 1, the ground lines 38 are individually grounded or electrically connected to each other with the main cable 10 and the branch cable 20 connected by the T branch connection unit 40 connected. It is connected. Thus, the joint-type branch-attached cable of the present invention is the trunk cable 1
Edge cutting is performed on the cable shielding layer.

Therefore, the joint type branch cable of the present invention can use the ground wire 38 to diagnose deterioration in each section between the connecting portions. Further, when a defective portion is found as a result of deterioration diagnosis for each section, the connecting portion can be disconnected and the defective portion can be easily replaced.

[0028]

As described above, in the joint-type branch cable of the present invention, the trunk cable is detachably electrically connected in series in the longitudinal direction, and one end of the branch cable branched from the middle of the trunk cable is detached. In a joint-type branch cable with a T-branch connection unit that enables electrical connection, a trunk cable has an insulating tube on a cable insulator that is terminated, and an outer periphery of the insulating tube is connected to the T-branch connection unit. Inside the insulating tube, the metal fittings are placed and the semiconductive rubber layer is provided from the outer periphery of the cable insulator adjacent to one end of the insulating tube to the inside of the insulating tube, extending along the longitudinal direction of the cable. The end portion of the semi-conductive rubber layer located at the position of the semi-conductive rubber layer extends in the longitudinal direction of the cable in an overlapping manner with respect to the end portion of the metal fitting, and between the metal fitting and the end portion of the semi-conductive rubber layer, a radial Away from Since it is configured such that the edge of the cable shielding layer is formed inside the insulating cylinder, (1) Deterioration diagnosis for each section between the connection sections during periodic inspection, or between the connection sections It is possible to constantly monitor the shielding layer current or voltage for each section, to enable early confirmation of an accident point in the event of an abnormality, and also to perform deterioration diagnosis of the connection unit itself, that is, electrical performance check. (2) Degradation diagnosis of the branch cable or constant monitoring is possible. (3) Furthermore, when a defective portion is found as a result of deterioration diagnosis for each section, the defective portion can be easily replaced by disconnecting the connecting portion. Such an effect can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a joint-type branched cable according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a trunk cable in the joint-type branched cable of FIG.

FIG. 3 is a diagram showing a schematic configuration of a joint-type branched cable.

FIG. 4 is a cross-sectional view of a conventional joint-type branched cable.

5 is an enlarged cross-sectional view of a trunk cable in the joint-type branch cable of FIG.

[Explanation of symbols]

1 Joint type branch cable 3 Cable shielding layer 4 cable insulation 5 conductors 10 trunk cable 20 branch cable 32 connection bracket 34 Insulating spacer 35 insulating tube 36 Fixing bracket 38 Ground wire 39 Semi-conductive tape 40 T branch connection unit 50 Semi-conductive rubber layer A Cable shield layer edge cutting part

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5G309 EA07                 5G355 AA03 BA02 BA11                 5G363 AA16 BA01 DA01 DB17                 5G375 AA02 CA02 CA19 CB06 CB14                       CB36 CB55 CD02 DB16 DB32                       EA17

Claims (2)

[Claims] 1. A joint type branch equipped with a T-branch connection unit for removably electrically connecting a trunk cable in series in the longitudinal direction and detachably electrically connecting one end of a branch cable branched from the middle of the trunk cable. In the attached cable, the trunk cable has an insulating tube on a cable insulator that has been subjected to a terminal treatment, and a connecting metal fitting for the T-branch connecting unit is arranged on an outer periphery of the insulating tube, and one end of the insulating tube is provided. A semiconductive rubber layer extending along the longitudinal direction of the cable from the outer peripheral portion of the cable insulator adjacent to to the inside of the insulating cylinder, and the semiconductive rubber layer positioned inside the insulating cylinder. The end of
Overlapping in the longitudinal direction of the cable with respect to the end of the metal fitting, and between the metal fitting and the end of the semi-conductive rubber layer, it is held at a distance in the radial direction, A joint type branched cable, wherein an edge cut portion of a cable shielding layer is formed in the insulating cylinder. 2. A semi-conductive tape is wound between the semi-conductive rubber layer located on the outer periphery of the cable insulator and a cable shielding layer adjacent to the cable insulator. 1-joint cable with branch.