CN201303245Y - Three-layered composite cable transition joint - Google Patents

Abstract

The utility model relates to a three-layer composite cable intermediate joint, which is characterized in that the inner layer of the joint is an electric field stress control layer with nonlinear impedance, the middle layer of the joint is an insulating layer, and the outer layer of the joint is a Semi-conductive layer for insulation and shielding. The beneficial effects of the utility model are: to provide a cable joint that can be molded with three layers of materials and extruded at the same time. It improves the quality of installation, and can be produced as heat-shrinkable or cold-shrinkable cable joints. It is used for new construction projects or repairs after cable failures. It can be used in cable tunnels, cable trenches or directly buried underground.

Description

Three-layer composite cable intermediate joint

technical field

The utility model belongs to a power cable interconnection device for power distribution network connection, in particular to a three-layer composite cable intermediate joint.

Background technique

At present, the cable heat-shrinkable intermediate joints used in the known distribution network are made of various pipes in the factory, and then constructed and installed at the engineering site, as shown in FIG. 1 . This type of heat-shrinkable joint is easily polluted by the environment during installation, such as dust and moisture in the air, etc.; in addition, the technical quality and responsibility of the installer are high, and it is difficult to fully reflect the design idea and guarantee the mechanical Dimensional physical parameters, low discharge level and poor power frequency tolerance are not ideal, and there are also hidden dangers in operation.

Contents of the invention

The purpose of this utility model is to provide a three-layer composite cable intermediate joint that combines three layers of materials with different requirements or extrudes them at the same time (three-layer co-extrusion) to overcome the existing cable heat shrinkable joints. Complicated installation and easy contamination.

In order to achieve the above object, the utility model is characterized in that: the inner layer of the joint is an electric field stress control layer with nonlinear impedance, the middle layer of the joint is an insulating layer, and the outer layer of the joint is a semiconductive layer that plays an insulating shielding role .

The above-mentioned electric field stress control layer can be made of rubber-plastic copolymer, silicone rubber or ethylene-propylene rubber, and its parameters are generally volume resistivity ≥ 10 ¹¹ ; dielectric constant ≥ 25; dielectric loss tangent ≯ 10‰.

The above insulation layer can be either rubber-plastic copolymer material, silicone rubber or ethylene-propylene rubber, and its thickness should be ≥ 1.5 times the insulation thickness of cables of the same voltage level.

The above-mentioned semi-conductive layer is conductive plastic or conductive rubber, and its resistivity is required to be ≤10 ² MΩ·m.

The above-mentioned semiconducting layer, insulating layer and electric field stress control layer have the same length.

The beneficial effects of the utility model are: to provide a cable joint that can be molded with 3 layers of materials and extruded at the same time. The requirements of workers improve the quality of installation, and can be produced as heat-shrinkable or cold-shrinkable cable joints. It is used for new construction projects or repairs after cable failures. It can be used in cable tunnels, cable trenches or directly buried underground.

Description of drawings

Figure 1 is a schematic diagram of the structure of a cable joint currently in use.

Fig. 2 is a schematic view of the longitudinal section of the utility model.

Fig. 3 is a structural schematic diagram of an embodiment of the utility model.

In the figure: 1-cable sheath, 2-metal shielding, 3-semiconductor shielding, 4-cable insulation, 5.-conductor, 6-connecting tube, 7-stress evacuation glue, 8-heat shrinkable insulating tube, 9-metal Shielding mesh and heat-shrinkable semi-conductive tube, 10-electric field stress control tube, 11-semiconductive layer, 12-insulation layer, 13-electric field stress control layer.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

The utility model is composed of a three-layer composite cable joint. The inner layer of the joint is an electric field stress control layer 13 with nonlinear impedance, the middle layer of the joint is an insulating layer 12, and the outer layer of the joint is an insulating shielding layer. Semiconducting layer 11.

Embodiment (Fig. 3):

When the utility model is in use, the metal shield 2, the semiconductor shield 3, the cable insulation 4, and the conductor 5 are stripped and cut according to the required size; the utility model is inserted and slid to one side of the cable joint area, and the conductors at both ends of the cable are used The connecting pipe 6 is connected, and the stress evacuation glue 7 is wrapped around the connecting pipe 6 and the insulating end, and then the utility model is pulled back to the joint area and centered, heated and shrunk, and wrapped with metal outside the shrunk joint and the metal shielding layer. Shielding net.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (5)

1. A three-layer composite cable intermediate joint, characterized in that: the inner layer of the joint is an electric field stress control layer with nonlinear impedance, the middle layer of the joint is an insulating layer, and the outer layer of the joint is an insulating shield The role of the semiconducting layer. 2. The three-layer composite cable intermediate joint according to claim 1, characterized in that: the electric field stress control layer is either a rubber-plastic copolymer material, or silicon rubber or ethylene-propylene rubber, and its parameter is volume resistivity ≥ 10 ¹¹ ; Dielectric constant ≥ 25; Dielectric loss tangent ≯ 10‰. 3. The three-layer composite cable intermediate joint as claimed in claim 1, characterized in that: the insulating layer can be either rubber-plastic copolymer material, or silicon rubber or ethylene-propylene rubber, and its thickness should be ≥ the insulation thickness of cables with the same voltage level. 1.5 times. 4. The three-layer composite cable intermediate joint according to claim 1, wherein the semi-conductive layer is made of conductive plastic or conductive rubber, and its resistivity is required to be ≤10 ² MΩ·m. 5. The three-layer composite cable intermediate joint according to claim 1, characterized in that: the semiconductive layer, the insulating layer, and the electric field stress control layer are of the same length.

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