CN111049071A

CN111049071A - Preparation method of integrally prefabricated intermediate joint

Info

Publication number: CN111049071A
Application number: CN201911355331.6A
Authority: CN
Inventors: 王刚; 王志明; 厉枫顺
Original assignee: Anhui Haohui Electric Power Co Ltd
Current assignee: Anhui Haohui Electric Power Co Ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-04-21

Abstract

The invention relates to the technical field of accessories of a crosslinked polyethylene insulated power cable, and discloses a preparation method of an integral prefabricated intermediate joint. The method avoids the die-closing seam on the insulation, solves the problem caused by the thinner shielding layer, ensures the insulation performance better and has longer service life.

Description

Preparation method of integrally prefabricated intermediate joint

Technical Field

The invention relates to the technical field of accessories of a crosslinked polyethylene insulated power cable, in particular to a preparation method of an integral prefabricated intermediate joint.

Background

The Chinese power industry has developed rapidly, the installed power generation capacity and annual energy generation capacity are the first in the world, the power equipment level is greatly improved, the large-capacity, high-parameter and environment-friendly unit is rapidly increased, the coverage area and the modernization degree of a power grid are continuously improved, the Chinese power industry has entered a new development stage of large power grids, large units, west-east power transmission, north-south mutual assistance and national networking, and the Chinese power industry is moving forward to higher targets of high efficiency, environmental protection, safety and economy. With the acceleration of urban construction, track construction, power station and power transmission facility construction, wide development space is brought to the power cable and the accessory industry thereof. Especially, the cable transmission line with long distance and large capacity makes the intermediate joint of the cable developed rapidly.

At present, for the intermediate joint of the crosslinked polyethylene insulated cable with the voltage of more than 66kV, the most widely applied at home and abroad is an integral prefabricated structure, wherein two main rubber parts have two structures. One is that: the method comprises the steps of firstly injecting semiconductive rubber into a mold by a rubber injection machine to form stress cones at two ends and a high-voltage shield in the middle, then injecting insulating rubber into the mold by the rubber injection machine to form stress cone insulation, and finally spraying a relatively thin semiconductive insulating shield layer outside the stress cone insulation. The other is as follows: the method comprises the steps of firstly injecting semiconductive rubber into a mold by a rubber injection machine to form stress cones at two ends and a high-voltage shield in the middle, then injecting insulating rubber into the mold by the rubber injection machine to form stress cone insulation, and finally injecting the semiconductive rubber into the mold by the rubber injection machine to form an insulating shield, wherein the insulating shield is thicker.

The intermediate joint of the two structures has enough electric strength, simple structure and light weight, but has the following defects in the using process: first, since the insulation shield is coated with a thin layer on the outside of the insulation, the insulation shield of the product may be scratched to expose the insulation during the installation of the product. Resulting in a reduction in the insulation properties of the product and even a breakdown of the product. Secondly, although the thickness of the insulation shield is increased, the insulation shield is not easy to damage during installation, after the middle joint is subjected to insulation injection molding, a mold closing seam is left outside the middle joint and needs to be polished, so that the insulation shield is not round, the electric field distribution in the rubber part is not uniform, and the insulation performance is reduced. Certain hidden danger exists for the safe operation of products in the future.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a preparation method of an integral prefabricated intermediate joint, which solves the problem that the insulation shield of a product is scratched to expose insulation in the process of installing the product in the prior art. The insulation performance of the product is reduced, even the product is broken down, and after the middle joint is subjected to insulation injection molding, a mold closing seam is left outside the middle joint and needs to be polished, so that the insulation shielding is not round, the electric field in the rubber part is not uniformly distributed, and the insulation performance is reduced.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of an integral prefabricated intermediate joint comprises the following steps:

s1, vulcanizing the mixed semi-conductive liquid silicon rubber subject stress cone mould by a rubber injection machine to prepare a stress cone;

s2, injecting the semi-conductive liquid silicone rubber into a mold containing a stress cone, and vulcanizing to prepare the high-voltage shield;

s3, injecting the semi-conductive liquid silicon rubber into an insulating outer shielding mould to prepare an insulating outer shielding;

and S4, finally, placing the stress cone and the high-voltage shielding mixed insulation shield at the corresponding position in a combined die, and injecting the mixed insulation liquid silicon rubber into the die by using a rubber injection machine to vulcanize the middle joint insulation, thereby manufacturing the middle joint integral rubber piece.

(III) advantageous effects

The invention provides a preparation method of an integral prefabricated intermediate joint, which has the following beneficial effects:

the process can be used for finally injecting the middle joint insulation, thereby not only avoiding the problem of a mold closing seam outside the middle joint insulation, but also solving the problem of product breakdown caused by the possibility that the coating is damaged during installation due to the thinner insulation shielding layer.

Drawings

FIG. 1 is a schematic diagram of a spraying structure of a conventional intermediate joint rubber part;

FIG. 2 is a schematic view of an injection molding structure of a conventional intermediate joint rubber part;

fig. 3 is a schematic structural view of the intermediate joint rubber member of the present invention.

In the figure: 1. a stress cone; 2. high-voltage shielding; 3. insulating the middle joint; 4. and (4) insulating and shielding.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 3, the present invention provides a technical solution: a preparation method of an integral prefabricated intermediate joint comprises the following steps:

s1, vulcanizing the mixed semi-conductive liquid silicon rubber subject stress cone mould by a rubber injection machine to prepare a stress cone 1;

s2, injecting the semi-conductive liquid silicone rubber into a mold containing the stress cone 1, and vulcanizing to prepare the high-voltage shield 2;

s3, injecting the semi-conductive liquid silicon rubber into an insulating outer shielding mould to prepare an insulating outer shielding 4;

and S4, finally, placing the stress cone 1 and the high-voltage shield 2 mixed insulating shield 4 into corresponding positions in a combined die, and injecting the mixed insulating liquid silicon rubber into the die by using a rubber injection machine to vulcanize the middle joint insulation 3 so as to manufacture the middle joint integral rubber piece.

In conclusion, the working process of the invention is as follows: firstly, injecting mixed semi-conductive liquid silicon rubber into a mold by a rubber injection machine for vulcanization to prepare a stress cone 1, then injecting the semi-conductive liquid silicon rubber into the mold containing the stress cone 1 for vulcanization to prepare a high-voltage shield 2, then preparing the stress cone 1 and an insulating outer shield 4, finally placing the stress cone 1, the high-voltage shield 2 and the insulating shield 4 into corresponding positions in a combined mold, injecting the mixed insulating liquid silicon rubber into the mold by the rubber injection machine for vulcanization to prepare an intermediate joint insulation 3, and thus preparing the intermediate joint integral rubber piece.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The preparation method of the integral prefabricated intermediate joint is characterized by comprising the following steps of:

s1, vulcanizing the mixed semi-conductive liquid silicon rubber subject stress cone mould by a rubber injection machine to prepare a stress cone (1);

s2, injecting the semi-conductive liquid silicone rubber into a mold containing the stress cone (1) to be vulcanized to form the high-voltage shield (2);

s3, injecting the semi-conductive liquid silicon rubber into an insulating outer shielding mould to prepare an insulating outer shielding (4);

and S4, finally, placing the stress cone (1) and the high-voltage shield (2) mixed insulating shield (4) into corresponding positions in a combined die, and injecting the mixed insulating liquid silicon rubber into the die by using a rubber injection machine to vulcanize the middle joint insulator (3) so as to manufacture the middle joint integral rubber piece.