Rubber mold and method for manufacturing factory joints of submarine electric power cables

Abstract

The invention discloses a rubber mold for manufacturing factory joints of submarine electric power cables. The rubber mold comprises an upper mold and a lower mold which are semi-cylinder-shaped, wherein the upper mold and the lower mold are butted to form a cable insulating recovery area; the diameter of the middle part of the cable insulating recovery area is larger than those of the two end parts; and the diameters of the two end parts are slightly larger than that of a cable; and injection-molding holes are arranged on the top part of the upper mold along the radial direction. The invention also discloses a method for manufacturing the factory joints of the submarine electric power cables. The method comprises the following steps of: installing the rubber mold, installing a metal injection-molding mold, injecting an insulating body material, cooling and disassembling the mold, finishing an insulating layer, carrying out high-temperature and high-pressure vulcanization and carryingout cooling and forming. The invention has the advantages that the problem of middle connection in the process of producing the submarine cables is solved, and the large-length supplying requirement is met; due to adoption of the hydrogenated-nitrile rubber mold, the problem that the performances of other materials are difficult for meeting the requirement is solved; the adopted process solves the recovery of the insulating layer and a shielding layer at the factory joint parts of the submarine cables, and the insulating performance meets the requirement of normal operation of the cables completely.

Description

technical field [0001] The invention relates to power cables, in particular to a rubber mold and a method for making factory joints of submarine power cables, which are suitable for the production of intermediate joints of various medium and high voltage cables, especially the production of factory joints of large-length submarine power cables. Background technique [0002] Since the biggest feature of submarine power cable production is large-length power transmission, factory joints (that is, joints made on-site in the factory during the production process of submarine power cables) must be used for cable splicing during the manufacturing process of submarine power cables. In the early days, high-voltage power cable joints were wrapped with self-adhesive tapes. Although it is simple and easy to implement, the problem is that the gap between the tapes is likely to cause electrical breakdown. In the 1980s, cross-linkable polyethylene tape was used to wrap and heat molded. Al...

AI Technical Summary

Problems solved by technology

In the early days, the high-voltage power cable joints used the self-adhesive tape wrapping method. Although it is simple and easy to implement, the problem is that the gap between the tapes is easy to cause electrical breakdown.

In the 1980s, cross-linkable polyethylene tape was used to wrap and heat molded. Although this method solved the problem that the gap between the tapes was easy to cause electrical breakdown, the polyethylene tape was easy to absorb dust and brought impurities into the high voltage. In power cable joints, it is easy to cause defects, especially when it is easy to form air bubbles in the joint

At present, many countries use large-diameter compact integral prefabricated joints. This kind of prefabricated joints is not only complicated to manufacture, but also the length of the cable outer sheath is broken during production, and the sealing and mechanical properties of the cable body cannot be achieved when it is restored. , especially after the prefabricated joint is finished, it cannot be bent and moved freely

In the 1990s, people developed molded connectors. Although this molded connector has many advantages, the production cycle is long and the cost is high. Especially in the insulation recovery process, it is difficult to prevent the insulation and shielding of the cable from being scalded by the metal mold. or pre-vulcanized or over-vulcanized

CN 2858253 Y announced the "cross-linked polyethylene insulated power cable intermediate joint welding and forming device below 500KV". The time for making intermediate joints with this device is shorter than that of prefabricated joints. It is suitable for the installation of flexible joints for submarine cables, but the structure of the device is relatively complicated

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