CN116526412A - Cold shrink intermediate joint of power cable and manufacturing process thereof - Google Patents

Abstract

The invention relates to the technical field of cable accessory manufacturing, in particular to a cold-shrink intermediate joint of a power cable and a manufacturing process thereof. The invention discloses a cold-shrink intermediate joint of a power cable, which comprises a conductor crimping pipe crimped at the outer side of a joint of two cable cores, wherein the conductor crimping pipe is positioned between cable insulations of the two cable cores, and an insulating strip is wrapped outside the cable insulations and the conductor crimping pipe; the cable insulation at both ends of the insulating tape is wrapped with a high dielectric constant tape. The technical problem solved by the invention is to develop a cold-shrink intermediate joint of a power cable, which does not need to be connected with a high-voltage shielding pipe and can reduce the production difficulty and the cost.

Description

Cold shrink intermediate joint of power cable and manufacturing process thereof

Technical Field

The invention relates to the technical field of cable accessory manufacturing, in particular to a cold-shrink intermediate joint of a power cable and a manufacturing process thereof.

Background

A cable intermediate joint, i.e. a cable joint in the middle of a cable line. The cable intermediate joint is a cable accessory for intermediate connection of cross-linked cables or oil-immersed cables with various voltage levels, and has the main functions of ensuring smooth circuits, keeping the cables sealed, ensuring the insulation level at the cable joint and ensuring the safe and reliable operation of the cable joint.

As shown in fig. 1, the conventional middle joint body for a middle-low voltage cable mainly includes four parts: the semi-conductive stress cone 11, the joint high-voltage shielding tube 12, the middle joint main insulation 14 and the joint outer shielding 15 are arranged in the joint high-voltage shielding tube 12, and the conductor crimping tube 13 is arranged in the joint high-voltage shielding tube. In order to shield the burr discharge and the like on the conductor crimping tube, both ends of the joint high-voltage shielding tube 12 should be longer than the conductor crimping tube 13, and the distance between the joint high-voltage shielding tube 12 and the semiconductive stress cone 11 should be controlled, if the distance is too short, the field strength near the stress cone and the shielding tube increases. The traditional intermediate joint not only increases the manufacturing cost of enterprises, but also needs to be accurate in size positioning during installation, and has lower installation efficiency. In addition, the existing intermediate joint is provided with a stress cone, the stress cone is required to be cast and molded firstly, then the insulating part is cast and molded, the process is complex, a plurality of molds are required, the production difficulty is increased, and the enterprise cost is also increased.

Accordingly, those skilled in the art have been working to develop a cold shrink intermediate joint for a power cable and a manufacturing process thereof that do not require a joint high voltage shielding tube and can reduce the difficulty and cost of production.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention discloses a cold-shrink intermediate joint for a power cable and a manufacturing process thereof, and aims to provide a cold-shrink intermediate joint for a power cable and a manufacturing process thereof, which do not need a high-voltage shielding pipe for the joint and can reduce the production difficulty and cost.

In order to achieve the above purpose, the invention provides a cold-shrink middle joint of a power cable, which comprises a conductor crimping pipe crimped outside the joint of two cable cores, wherein the conductor crimping pipe is positioned between cable insulations of the two cable cores, and an insulating strip is wrapped outside the cable insulations and the conductor crimping pipe; the cable insulation at two ends of the insulation strip is wrapped with a high dielectric constant strip.

Preferably, the high dielectric constant tape is in lap joint with the cable shield. During connection, one section of the cable shielding layer at the connection end is peeled off, the cable shielding layer is polished to be smooth, and one end of the high-dielectric-constant strip material is lapped, wrapped and wound on the cable shielding layer.

Preferably, the cable shielding layer is coated with a semiconductive paint.

Preferably, the high dielectric constant tape has a dielectric constant greater than 20.

Preferably, the insulating tape and the cable are insulated and wrapped with an intermediate connector body.

Preferably, the intermediate connector body includes an intermediate connector main insulation and an outer connector shield, which are cast to form the intermediate connector body.

Preferably, the outer shield of the connector is externally sprayed with a semi-conductive paint as the outer shield of the connector.

Preferably, the two ends of the conductor crimping tube are reversely tapered, the tapered connecting end is arranged at the insulated end part of the cable, and the insulating strip is wrapped outside the connecting end and the conductor crimping tube. The two ends of the conductor crimping tube are designed to be reverse cones, the cable is insulated with conical connecting ends corresponding to the reverse cones, the insulating strips fill and wrap the two cones in opposite directions, and internally protruding wrapping parts are formed at the two ends of the conductor crimping tube; the structure can play a role in balancing the electric field to a certain extent, and the problem of nonuniform electric field caused by the enhancement or weakening of the electric field is avoided.

Preferably, the outer diameter of the insulating tape is similar to the outer diameter of the cable insulation.

The invention also provides a manufacturing process of the power cable cold-shrink intermediate joint, which comprises the following steps of:

1) Stripping the cable shielding layer and the cable insulation at the end part of the cable to be connected, and exposing a part of the cable shielding layer from the cable insulation;

2) Processing one end of the cable insulation exposed out of the cable shielding layer into a conical connecting end;

3) Sleeving the cast middle joint main body to one end of a cable, then pressing and connecting a conductor crimping pipe, and wrapping an insulating strip outside the conductor crimping pipe and the connecting end until the outer diameter of the insulating strip is nearly consistent with that of the cable insulation;

4) Wrapping a high-dielectric-constant strip outside the cable shielding layer, and wrapping two layers in a half lap joint mode;

5) And moving the middle joint main body to the middle part, and uniformly spraying the semiconductor paint outside the middle joint main body.

The beneficial effects of the invention are as follows:

by eliminating the joint high-voltage shielding pipe, the distance between the joint high-voltage shielding pipe and the semiconductive stress cone is not required to be controlled, the joint high-voltage shielding pipe and the joint outer shielding forming step are omitted, the installation efficiency is improved, the manufacturing cost of enterprises is reduced, and the field intensity is not increased because the distance between the joint high-voltage shielding pipe and the semiconductive stress cone is too short. Meanwhile, the high-dielectric-constant strip is adopted to replace the stress cone, and the stress cone is firstly molded and then is injection-molded for insulation, so that the processing is complex. On the other hand, the middle joint main body is formed by pouring the middle joint main insulation and the joint outer shielding, is suitable for connecting the middle and low voltage power cables, can effectively even the electric field of the cable shielding fracture, and has small size and convenient installation.

Drawings

FIG. 1 is a schematic structural view of a prior art intermediate joint;

fig. 2 is a schematic structural view of an embodiment of the present invention.

In the above figures: 1. a high dielectric constant tape; 2. the middle joint is mainly insulated; 3. the joint is externally shielded; 4. an insulating tape; 5. a conductor crimping tube; 6. insulating the cable; 7. a cable core; 8. a cable shield.

Detailed Description

The present invention will be further described with reference to the drawings and examples, and it should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific manner, and thus should not be construed as limiting the present invention.

As shown in fig. 2, the invention provides a cold-shrink intermediate joint of a power cable, which comprises a conductor crimping pipe 5 crimped outside the joint of two cable cores 7, wherein the conductor crimping pipe 5 is positioned between cable insulations 6 of the two cable cores 7, and the cable insulations 6 and the conductor crimping pipe 5 are wrapped with an insulating strip 4; the cable insulation 6 at both ends of the insulating tape 4 is wrapped with the high dielectric constant tape 1. The two ends of the conductor crimping pipe 5 are reversely tapered, the tapered connecting end is arranged at the end part of the cable insulation 6, the connecting end and the conductor crimping pipe 5 are externally wrapped with an insulation strip 4, and the outer diameter of the insulation strip 4 is similar to the outer diameter of the cable insulation 6. By designing both ends of the conductor crimping tube 5 to be reversely tapered, the cable insulation 6 has tapered connection ends corresponding to the reversely tapered shapes, the insulation tape 4 fills and wraps the two tapered shapes in opposite directions, and internally protruding wrapping parts are formed at both ends of the conductor crimping tube 5; the structure can play a role in balancing the electric field to a certain extent, and the problem of nonuniform electric field caused by the enhancement or weakening of the electric field is avoided.

In detail, the high dielectric constant tape 1 is lap-jointed with the cable shield 8. During connection, one section of the cable shielding layer 8 at the connection end is peeled off, the cable shielding layer 8 is polished to be smooth, the cable shielding layer 8 is coated with semiconductor paint, and one end of the high-dielectric-constant strip 1 is lapped, wrapped and wound on the cable shielding layer 8. The high dielectric constant tape 1 has a dielectric constant greater than 20. Meanwhile, the insulating strip 4 and the cable insulation 6 are wrapped by an intermediate joint main body, the intermediate joint main body comprises an intermediate joint main insulation 2 and a joint outer shield 3, and the intermediate joint main insulation 2 and the joint outer shield 3 are cast to form the intermediate joint main body. The outer side of the joint outer shield 3 is sprayed with semi-conductive paint as the joint outer shield.

In the embodiment, by eliminating the joint high-voltage shielding pipe, the distance between the joint high-voltage shielding pipe and the semiconductive stress cone is not required to be controlled, the joint high-voltage shielding pipe and the joint outer shielding forming step are omitted, the installation efficiency is improved, the manufacturing cost of enterprises is reduced, and the field intensity is not increased because the distance between the joint high-voltage shielding pipe and the semiconductive stress cone is too short. Meanwhile, the high dielectric constant strip 1 is adopted to replace the stress cone, and the stress cone is firstly molded and then is injection-molded for insulation, so that the processing is complex. On the other hand, the middle joint main insulator 2 and the joint outer shield 3 are cast into a middle joint main body, so that the middle joint main insulator is suitable for connecting a middle-low voltage power cable, can effectively even the electric field of a cable shielding fracture, and is small in size and convenient to install.

The invention also provides a manufacturing process of the power cable cold-shrink intermediate joint, which comprises the following steps of:

1) Stripping the cable shield 8 and the cable insulation 6 at the end of the cable to be connected, and exposing a portion of the cable shield 8 to the cable insulation 6;

2) Machining one end of the cable insulation 6 exposed out of the cable shielding layer 8 into a conical connecting end;

3) Sleeving the cast middle joint main body to one end of a cable, then pressing and connecting a conductor press joint pipe (5), and wrapping an insulating strip 4 outside the conductor press joint pipe 5 and the connecting end until the outer diameter of the insulating strip is nearly consistent with that of the cable insulation 6;

4) Wrapping the high dielectric constant strip 1 outside the cable shielding layer 8, and wrapping two layers in a half lap joint mode;

5) And moving the middle joint main body to the middle part, and uniformly spraying the semiconductor paint outside the middle joint main body.

The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.

Claims (10)

1. A power cable cold shrink intermediate joint, characterized in that: the cable comprises a conductor crimping pipe (5) which is crimped outside a joint of two cable cores (7), wherein the conductor crimping pipe (5) is positioned between cable insulations (6) of the two cable cores (7), and the cable insulations (6) and the conductor crimping pipe (5) are wrapped with insulating strips (4); the cable insulation (6) at two ends of the insulation strip (4) is wrapped with the high dielectric constant strip (1).

2. The power cable cold shrink intermediate joint of claim 1, wherein: the high dielectric constant strip (1) is in lap joint with the cable shielding layer (8).

3. The power cable cold shrink intermediate joint of claim 2, wherein: the cable shielding layer (8) is externally coated with a semiconductive paint.

4. The power cable cold shrink intermediate joint of claim 1, wherein: the high dielectric constant tape (1) has a dielectric constant greater than 20.

5. The power cable cold shrink intermediate joint of claim 1, wherein: the insulating strip (4) and the cable insulation (6) are wrapped with an intermediate joint main body.

6. The power cable cold shrink intermediate joint of claim 5, wherein: the middle joint main body comprises a middle joint main insulator (2) and a joint outer shield (3), and the middle joint main insulator (2) and the joint outer shield (3) are cast to form the middle joint main body.

7. The power cable cold shrink intermediate joint of claim 6, wherein: and the outer side of the joint outer shield (3) is sprayed with semi-conductive paint.

8. The power cable cold shrink intermediate joint of claim 1, wherein: the two ends of the conductor crimping tube (5) are reversely conical, the conical connecting end is arranged at the end part of the cable insulation (6), and the insulating strip (4) is wrapped outside the connecting end and the conductor crimping tube (5).

9. The power cable cold shrink intermediate joint of claim 1, wherein: the outer diameter of the insulating strip (4) is similar to the outer diameter of the cable insulation (6).

10. A process for manufacturing a cold-shrink intermediate joint for an electrical power cable, the cold-shrink intermediate joint for an electrical power cable according to any one of claims 1 to 9, characterized in that: the method comprises the following steps:

1) Stripping the cable shielding layer (8) and the cable insulation (6) at the end of the cable to be connected, and exposing a part of the cable shielding layer (8) to the cable insulation (6);

2) Machining one end of the cable insulation (6) exposed out of the cable shielding layer (8) into a conical connecting end;

3) Sleeving the cast middle joint main body to one end of a cable, then pressing and connecting a conductor press joint pipe (5), and wrapping an insulating strip (4) outside the conductor press joint pipe (5) and the connecting end until the outer diameter of the insulating strip is nearly consistent with that of the cable insulation (6);

4) Wrapping the high-dielectric-constant strip (1) outside the cable shielding layer (8), and wrapping two layers in a half-lap mode;

5) And moving the middle joint main body to the middle part, and uniformly spraying the semiconductor paint outside the middle joint main body.