7-stranded steel core aluminum stranded wire crimping method for round wire concentric lay overhead electrical stranded conductor

Abstract

The invention discloses a 7-stranded steel core aluminum stranded wire crimping method for a round wire concentric lay overhead electrical stranded conductor. The method comprises steps: a butted aluminum stranded wire is firstly peeled off for a distance to expose the middle steel strand, and an aluminum splicing tube sleeves the wire; then, the steel core aluminum stranded wire passes through anouter embedded layer aluminum tube, a wire shaping ring sleeves the steel core aluminum stranded wire, and an inner embedded layer aluminum tube is inserted between the inner aluminum strand layer and the steel core; after the unfolded aluminum stranded wire is repaired, the steel core splicing embedded aluminum tube sleeves two butted wire steel core wire ends; a full-tension steel splicing tubesleeves the steel core splicing embedded aluminum tube; through crimping, the steel core splicing embedded aluminum tube sleeve is engaged with the steel core; and finally, the aluminum splicing tubemoves back to the crimping position, and through crimping, the inner embedded layer aluminum tube and the outer embedded layer aluminum tube are tightly fit. Pressure damage, under pressure and strand loosening of the steel core aluminum stranded wire can be avoided, the connection reliability is good, the manufacturing is easy, the crimping quality is higher, nondestructive testing does not happen, and the labor intensity and the engineering cost are reduced.

Description

technical field [0001] The invention belongs to the technical field of butt joints of seven stranded steel-cored aluminum stranded wires of round concentric stranded overhead conductors, and in particular relates to a crimping method for 7 stranded steel-cored aluminum stranded wires of round concentric stranded overhead conductors. Background technique [0002] The existing steel-cored aluminum stranded wire full-tension splicing tube is mainly composed of a steel crimping tube and an aluminum crimping tube. Then use the aluminum alloy crimping tube to crimp the aluminum alloy splicing tube, aluminum stranded wire and steel stranded wire together. This traditional crimping method is prone to two problems: [0003] (1) Damage to the steel core caused by the crimping of the steel core connecting tube. [0004] In the traditional splicing process of overhead conductors in power transmission and transformation projects, the joints of the steel-reinforced aluminum stranded wir...

AI Technical Summary

Problems solved by technology

[0004] In the traditional splicing process of overhead conductors in power transmission and transformation projects, the joints of the steel-reinforced aluminum stranded wire and the galvanized steel stranded wire (or aluminum-clad steel stranded wire) of the ground wire are directly covered with steel strands by steel splicing tubes and hydraulically connected. , if the hardness of the steel splicing pipe and the steel strand does not match, the size of the crimping die is unreasonable, and the crimping pressure is insufficient, defects such as undervoltage, loose strands, overpressure, and steel wire surface damage are prone to occur, resulting in the holding force of the joint not meeting the standard Require

Among the factors that cause steel strand crimping defects of steel cored aluminum strand and ground wire, the hardness mismatch between steel splicing pipe and steel strand is the most unavoidable. In the production process of aluminum clad steel strand, cold drawn steel wire The hardness of the cold-drawn steel wire is reduced, resulting in a lower hardness of the steel strand than that of the steel splicing tube. When crimping, the inner wall of the steel splicing tube bites the steel strand wire, resulting in the grip of the joint. Focus on lowering

[0005] (2) It is difficult to guarantee the crimping quality of aluminum connecting pipe

[0008] In winter, when the temperature drops, because the steel core is in the elastic range, the cross section of the steel core becomes thinner, the pressure applied by the steel core to the aluminum strand decreases, and the cross section of the aluminum strand also shrinks, but because the aluminum strand has already undergone yield hardening, The cross-section of the aluminum strands did not expand due to the reduction in pressure, which resulted in gaps between the aluminum strands

[0009] Rainwater, air, dirt, and corrosive media infiltrate the gap between the aluminum strands of the joint, oxidize the surface of the aluminum strands, and generate aluminum oxide, which leads to increased contact resistance and heat generation at the crimping joints of the steel-reinforced aluminum strands. , eventually failing

[0010] In order to solve the problems of damage to the steel core and unstable crimping quality of aluminum splicing tubes that are prone to occur in traditional crimping methods, it is necessary to design a new type of full-tension aluminum-embedded crimping process for steel-reinforced aluminum stranded wire. Twisted wire butt joint crimping is easier to implement, the crimping quality is higher, and the crimping joint can avoid non-destructive testing, reducing labor intensity and engineering costs

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