Middle and low voltage cable welding type intermediate joint

Abstract

A welding type intermediate joint for medium and low voltage cables at least comprises a welding layer, a conductor shielding recovery layer, an insulation recovery layer and an insulation shielding recovery layer which are sequentially arranged from inside to outside. The welding layer is connected between two adjacent sections of cable conductors; the insulation shielding recovery layer comprises an inner layer and an outer layer, the inner layer is a semi-conductive paint layer, and the outer layer is a first semi-conductive belt wrapping layer. On one hand, the installation time can be greatly reduced, and on the other hand, the electric field at the conductor connection position can be more stable; in addition, the inner layer of the insulation shielding recovery layer adopts a semi-conductive paint layer, so that the recovered cable insulation shielding thickness is more uniform.

Description

Technical Field

[0001] The utility model relates to the technical field of cable joints, in particular to a medium and low voltage cable fusion type intermediate joint. Background Art

[0002] In recent years, medium and low voltage 10 - 35kV aluminum (alloy) core conductor power cables have been widely adapted to different types of intermediate joints such as cold shrinkage, heat shrinkage, and wrapping type. The overall electrical and mechanical properties have reached a relatively high level. Existing cable intermediate joints usually use a connecting pipe to connect the aluminum (alloy) core conductor. After conductor shielding and insulation restoration, there is a protrusion at the conductor connection position, which not only affects the appearance but also causes uneven electric fields at this position, resulting in a situation where there may be relatively large potential safety hazards during long-term operation of the intermediate joint. Moreover, using a connecting pipe for installation is time-consuming and laborious. Furthermore, when the insulation shielding layer of the existing cable is restored, it is usually directly wrapped with a semi-conductive tape, resulting in uneven insulation shielding layers and affecting insulation performance. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the above deficiencies of the prior art and provide a medium and low voltage cable fusion type intermediate joint with high electric field stability, time-saving and labor-saving installation, high restoration quality, and high reliability.

[0004] The technical solution of the utility model is: a medium and low voltage cable fusion type intermediate joint, at least including a welding layer, a conductor shielding restoration layer, an insulation restoration layer, and an insulation shielding restoration layer, which are arranged in sequence from the inside to the outside; the welding layer is connected between adjacent two sections of cable conductors; the insulation shielding restoration layer includes two layers, the inner layer is a semi-conductive paint layer, and the outer layer is a first semi-conductive tape wrapping layer.

[0005] Further, the welding layer is a tungsten inert gas (TIG) welding layer.

[0006] Further, the conductor shielding restoration layer includes two layers, the inner layer is a semiconductor nylon cloth winding layer, and the outer layer is a second semi-conductive tape wrapping layer; the semiconductor nylon cloth is wound around the welding layer and the outer diameters of the two sections of cable conductors near the welding layer, and the second semi-conductive tape wrapping layer is wrapped outside the semiconductor nylon cloth winding layer.

[0007] Further, the insulation restoration layer is wrapped with an insulating tape to form a structure consistent with the outer diameter of the cable body insulation layer and is melt-connected with the cable body insulation layer.

[0008] Further, the semi-conductive paint layer is formed by directly spraying semi-conductive paint on the outside of the insulation restoration layer.

[0009] Furthermore, the intermediate joint also includes a metal shielding recovery layer, an inner sheath recovery layer, an armor recovery layer and an outer sheath recovery layer which are sequentially arranged from the inside to the outside.

[0010] Furthermore, the metal shielding restoration layer is formed by connecting the original metal shielding layers on both sides of the cable body using a copper mesh and a copper braided wire.

[0011] Furthermore, the inner sheath recovery layer is formed by wrapping the original inner sheaths on both sides of the cable body with a waterproof tape.

[0012] Furthermore, the armor restoration layer is formed by connecting the original cable armors on both sides of the cable body using copper braided wire.

[0013] Furthermore, the outer sheath recovery layer is formed by shrinking or wrapping a heat shrinkable sheath tube or an armor tape around the inner sheath recovery layer and the armor recovery layer.

[0014] Beneficial effects of the utility model:

[0015] (1) By setting a welding layer between two sections of cable conductors, the overall outer diameter is significantly reduced compared with the existing method of crimping with a connecting tube, and the electric field at the connection position of the cable conductor is more stable; further, the use of an argon arc welding layer can prevent the aluminum core cable from cracking or welding through during welding, greatly reducing the difficulty of welding;

[0016] (2) The inner layer of the insulation shielding recovery layer adopts a semi-conductive paint layer, which can make the insulation shielding layer more uniform and delicate, which is conducive to the recovery of insulation;

[0017] (3) The conductor shielding recovery layer provides good mechanical strength and stability by setting nylon cloth as the support layer of the semiconductor material, which can ensure the uniform wrapping of the semi-conductive tape and prevent the unevenness or breakage of the conductor shielding layer during use, thereby maintaining stable electrical performance;

[0018] (4) The insulation recovery layer is wrapped with insulating tape and combined with a fusion connection method, and the thickness is significantly reduced, which can be consistent with the thickness of the insulation layer of the cable body. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the recovery structure of the cable conductor part of the embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the internal recovery structure of the cable body of the embodiment of the utility model.

[0021] Description of the accompanying drawings:

[0022] 1. Cable conductor; 2. Welding layer; 3. Conductor shielding recovery layer; 4. Insulation recovery layer; 5. Insulation shielding recovery layer; 6. Metal shielding layer; 7. Metal shielding recovery layer; 8. Inner sheath recovery layer; 9. Armor recovery layer; 10. Cable armor; 11. Outer sheath recovery layer; 12. Outer sheath of cable body. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 1 and Figure 2 As shown: a medium and low voltage cable fusion type intermediate joint, including a welding layer 2, a conductor shielding recovery layer 3, an insulation recovery layer 4, an insulation shielding recovery layer 5, a metal shielding recovery layer 7, an inner sheath recovery layer 8, an armor recovery layer 9 and an outer sheath recovery layer 11 arranged in sequence from the inside to the outside.

[0025] Specifically, in this embodiment, the welding layer 2 is connected between two adjacent sections of the cable conductor 1, and the welding layer 2 is preferably welded by argon arc welding, thereby abandoning the conventional form of crimping with a connecting tube. Among them, the cable conductor 1 is an aluminum or aluminum alloy conductor, and the welding layer 2 is connected to the two sections of the cable conductor 1 with equal diameters. The reason why this embodiment uses argon arc welding for welding is that the thermal conductivity of aluminum is 1 to 3 times greater than that of copper, and it is easy to heat up, but this material is not resistant to high temperatures and has a large coefficient of expansion when heated, which easily causes welding deformation; moreover, aluminum is also prone to cracks and weld penetration during welding, making welding more difficult. By using argon arc welding, compared with welding methods such as hot melt welding, it is possible to prevent aluminum core cables from cracking and welding penetration during welding, greatly reducing the difficulty of welding.

[0026] In this embodiment, the conductor shielding recovery layer 3 includes two layers, the inner layer is a semiconductor nylon cloth winding layer, and the outer layer is a semi-conductive tape winding layer. Among them, the semiconductor nylon cloth is firstly wound on the welding layer and the outer diameter of the two sections of the cable conductor close to the welding layer, and then the high-performance semi-conductive tape is used for wrapping, so as to realize the recovery of the conductor shielding recovery layer. By setting nylon cloth as the support layer of the semiconductor material, good mechanical strength and stability are provided, which can ensure the uniform wrapping of the semi-conductive tape, prevent the unevenness or breakage of the conductor shielding layer during use, thereby maintaining stable electrical performance; and the conductive tape can effectively restore the shielding function of the cable, prevent the influence of electromagnetic interference, and combine the structure of the semiconductor nylon cloth to help improve the electrical performance of the conductor shielding layer, thereby enhancing the anti-interference ability of the cable.

[0027] In this embodiment, the insulation restoration layer 4 is formed by winding a high-performance cross-linked polyethylene insulating tape into a structure with the same outer diameter as the insulation layer of the cable body, and then the insulation layer of the cable body and the wound insulating tape are combined by heating and melting to restore the structure of the insulation layer of the cable body.

[0028] In this embodiment, the insulation shield restoration layer 5 includes two layers, an inner layer of semi-conductive paint layer and an outer layer of semi-conductive tape winding layer which is the same as the conductor shield restoration layer. The insulation shield restoration layer 5 is formed by directly spraying semi-conductive paint on the outside of the restored insulation restoration layer to form a semi-conductive paint layer, and then winding and restoring with a high-performance semi-conductive tape. By using the semi-conductive paint layer in this embodiment, the insulation shield layer can be made more uniform and delicate, which is beneficial to the restoration of insulation.

[0029] In this embodiment, the metal shield restoration layer 7 is formed by connecting the original metal shield layers 6 on both sides of the cable body with a copper mesh and copper braided wire, so as to restore the metal shield of the cable body. For example, the copper mesh can be used as an internal shield layer to provide a strong shielding effect, while the copper braided wire is used for external shielding and structural reinforcement.

[0030] In this embodiment, the inner sheath restoration layer 8 is formed by winding the original inner sheaths on both sides of the cable body with a waterproof tape.

[0031] In this embodiment, the armor restoration layer 9 is formed by connecting the original cable armors 10 on both sides of the cable body with a copper braided wire to restore the cable armor.

[0032] In this embodiment, the outer sheath restoration layer 11 is formed by using a heat-shrinkable sheath or armor tape to shrink or wind on the inner sheath restoration layer 8 and the armor restoration layer 9 to restore the outer sheath 12 of the cable body.

[0033] The installation process of the intermediate joint in this embodiment is as follows: (1) Cut and process the cable body; (2) Weld and restore the cable conductor; (3) Restore the conductor shield layer; (4) Restore the insulation; (5) Restore the insulation shield; (6) Restore the metal shield layer; (7) Restore the inner sheath; (8) Restore the armor layer; (9) Restore the outer sheath.

[0034] The design principle of this embodiment is: since the thermal conductivity of aluminum is 1 to 3 times greater than that of copper, it is easy to heat up, but this material is not resistant to high temperatures and has a large coefficient of expansion when heated, which easily causes welding deformation; moreover, this material is also prone to cracks and weld penetration during welding, making welding more difficult. This embodiment adopts argon arc welding, combined with the various layer restoration technology of the cable fusion type intermediate joint, to restore the cable conductor shielding, insulation, insulation shielding, metal shielding, inner sheath, armor and outer sheath, thereby avoiding the existing situation that after the aluminum (alloy) core conductor is connected by a connecting pipe, the conductor shielding and insulation restoration are performed, and the conductor connection position has a bulge, which not only affects the appearance but also causes the electric field at this position to be uneven, and eliminates the situation that the fusion type intermediate joint may have a large safety hazard during long-term operation.

[0035] To sum up, the intermediate joint of the utility model directly connects the conductors by welding the conductors without using a connecting tube to connect the cable body. Compared with the aluminum core cable fusion-type intermediate joint which uses an aluminum connecting tube for crimping, the use of a direct welding layer can significantly reduce the insulation thickness restored by melting, which on the one hand reduces the installation time, and on the other hand makes the electric field at the conductor connection position more stable; in addition, the inner layer of the insulation shielding recovery layer uses a semi-conductive paint layer, which can make the restored cable insulation shielding thickness more uniform.

Claims

1. A medium and low voltage cable fusion type intermediate joint, characterized in that: It at least includes a welding layer, a conductor shielding recovery layer, an insulation recovery layer and an insulation shielding recovery layer which are arranged in sequence from the inside to the outside; the welding layer is connected between two adjacent sections of cable conductors; the insulation shielding recovery layer includes two layers, the inner layer is a semi-conductive paint layer, and the outer layer is a first semi-conductive tape wrapping layer.

2. The medium and low voltage cable fusion type intermediate joint according to claim 1 is characterized in that: The welding layer is a argon arc welding layer.

3. The medium and low voltage cable fusion type intermediate joint according to claim 1 is characterized in that: The conductor shielding recovery layer includes two layers, the inner layer is a semiconductor nylon cloth winding layer, and the outer layer is a second semi-conductive tape winding layer; the semiconductor nylon cloth is wound around the welding layer and the outer diameter of the two sections of cable conductors close to the welding layer, and the second semi-conductive tape winding layer is wound around the outside of the semiconductor nylon cloth winding layer.

4. The medium and low voltage cable fusion type intermediate joint according to claim 1, characterized in that: The insulation recovery layer is wrapped with an insulation tape to form a structure consistent with the outer diameter of the cable body insulation layer, and is fused and connected with the cable body insulation layer.

5. The medium and low voltage cable fusion type intermediate joint according to claim 1, characterized in that: The semi-conductive paint layer is formed by directly spraying the semi-conductive paint on the outside of the insulation recovery layer.

6. The medium and low voltage cable fusion type intermediate joint according to claim 1, characterized in that: The intermediate joint also includes a metal shielding recovery layer, an inner sheath recovery layer, an armor recovery layer and an outer sheath recovery layer which are sequentially arranged from the inside to the outside.

7. The medium and low voltage cable fusion type intermediate joint according to claim 6, characterized in that: The metal shielding restoration layer is formed by connecting the original metal shielding layers on both sides of the cable body using a copper mesh and a copper braided wire.

8. The medium and low voltage cable fusion type intermediate joint according to claim 6, characterized in that: The inner sheath recovery layer is formed by wrapping the original inner sheaths on both sides of the cable body with a waterproof tape.

9. The medium and low voltage cable fusion type intermediate joint according to claim 6, characterized in that: The armor restoration layer is formed by connecting the original cable armors on both sides of the cable body with copper braided wire.

10. The medium and low voltage cable fusion type intermediate joint according to claim 6, characterized in that: The outer sheath recovery layer is formed by shrinking or wrapping a heat shrinkable sheath tube or an armor tape around the inner sheath recovery layer and the armor recovery layer.

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