Sparsely twisted type expanded lead

Abstract

The invention aims at providing a sparsely twisted type expanded lead which can achieve large expansion rate and solves the problem of strand-jumping caused by poor structural stability of a lead. The lead sequentially comprises a core layer, an inner layer, an middle layer and an outer layer from inside to outside, the core layer is formed by twisting and winding steel wires, the inner layer and the outer layer are of single-layer structures, the middle layer is of at least one-layer structure, the inner layer and the middle layer are formed by twisting and winding round linear leads with diameter of D1 and D2 or T-shaped leads with height of H1 and H2, and the outer layer is formed by twisting and winding round linear leads with diameter of D1 and D2 or T-shaped leads with height of H1 or H2, wherein D2 is smaller than D1, and H2 is smaller than H1. The inner layer, the middle layer and the outer layer are formed by twisting and winding aluminum wires, the adjacent layers of the aluminum wires are stranded reversely, and the outermost layer is stranded towards the right direction. Compared with a common twisting and winding wire, strand-jumping critical tension of the sparsely twisted type expanded lead is improved, the inner layer has no remarkable indentation after a critical tension test is performed on the expanded lead, and the problem of instability of the expanded lead caused by excessive gaps is resolved.

Description

technical field [0001] The invention belongs to the field of conductors of overhead power transmission lines, and in particular relates to a sparsely twisted wire with expanded diameter. Background technique [0002] When the transmission line is in a high-voltage state or a high-altitude geographical location, the electric field, magnetic field, audible noise and radio interference level of the overhead line will exceed the relevant requirements. Therefore, if the design uses ordinary wires, such as the attached figure 1 As shown in the schematic diagram of the steel-reinforced aluminum stranded wire, it is necessary to increase the cross-section of the conductor and the number of splits of the conductor, which will inevitably increase the use of the conductor, the structural size of the iron tower, and the width of the line corridor, thereby increasing the project investment. Wasted. [0003] Expanded wires have a larger diameter and better electrical performance than wir...

AI Technical Summary

Problems solved by technology

The defects of the hollow expanded diameter wire include: firstly, it cannot withstand high tensile force, and at the same time, due to the inconsistency of the hardness of the steel wire and the aluminum wire, it is difficult to twist, and the resilience of the steel wire will lead to the instability of the wire structure; secondly, because of the use of steel wire, Increase the overall weight of the wire, and at the same time increase the gravity on the tower

For example, the application number is CN200320114093.8, and the patent name of the invention is "Sparse Wound Expanded Steel Core Aluminum Stranded Wire". On the outer side of the wire layer, the structure is a common sparse-winding expansion wire with a limited diameter expansion rate. After the expansion ratio reaches a certain level, the stability of the wire structure is poor, which may cause defects such as jumping strands in the pay-off overweight, and it is easy to Stranded wire collapse due to uneven layer distribution

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