RU2703452C1 - Symmetric four-pair cable with three-layer film-film-corrugated film insulation of strands - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to electrical engineering and can be used in makeups of symmetric communication cables within a shared network or structured cable systems. Disclosed is a cable comprising insulated conductors, twisted into pairs with different pitch of twisting in a common layer, with an outer polymer shell, insulation of each core of which is made in the form of three-layer film-film-corrugated film insulation of equal size throughout the entire section of each conductive core, and the outer film is in contact with the film-corrugated insulation of each conductor along the entire section of each conductor along the entire length of the symmetrical cable.EFFECT: reduction of relative dielectric permeability of cable conductor insulation and reduction of attenuation factor due to reduction of losses in insulation of conductors and capacitive component of influence between pairs.1 cl, 2 dwg

Description

The invention relates to the field of electrical engineering and can be used in the construction of symmetric communication cables on public networks and structured cable systems.

In communication cables on public networks and structured cabling systems, depending on the category, various types of insulation of cable conductors are used: for cable conductors of category 1, polyethylene with a relative dielectric constant of 2.3 is used as insulation of conductors; for cables of category 3, a dielectric material is used for insulation of cores also with a relative permittivity of 2.3; for cables of category 5e, cellular polyethylene with a sheath is used as insulation veins - film-porous polyethylene with a relative dielectric constant of 2.0; Category 6 cables use Teflon core insulation with a relative dielectric constant of 2.0.

The known design of a four-pair cable containing copper conductors in dielectric insulation, twisted in pairs with different pitch, in a common external dielectric sheath ("Structured cable systems" authors: AB Semenov, SK Strizhakov, IR Sunchely, DMK Publishing House, M. 2002, 4th edition, p. 109, Fig. 3.4 and 3.5). The disadvantage of this design is the relatively high value of the relative permittivity of the insulation of the cable conductors.

A known four-pair cable design, consisting of two fours, each four of which is twisted from two pairs, with film-porous core insulation and an external polymer sheath ("Structured cable systems" authors: AB Semenov, SK Strizhakov, I. R. Suncheley, DMK publishing house, M. 2002, 4th edition, p. 106, Fig. 3.2 b). The disadvantage of this design is also the high value of the relative dielectric constant of the insulation of the cores.

The proposed solution closest in technical essence is the design of four pair cables described in the prospectus of Teldor, Wires and Cables, Russia Ltd. 2006, 223 pp., P. 35 (website: www.teldor.com.). The cable is designed for indoor stationary laying and consists of four unshielded twisted (twisted) pairs twisted together into a core, protected by a PVC sheath; core diameter 0.51 mm, polyolefin insulation (film-porous film insulation, insulated core outer diameter 0.9 mm; cable outer diameter 5.0 mm). Given the maximum signal propagation speed equal to 0.7 of the speed of light, the relative dielectric constant of the core insulation is 2.0, which is also the main disadvantage of this cable.

The technical result, to which the present invention is directed, is to reduce the relative dielectric constant of the insulation of the cable conductors.

To achieve a technical result in a symmetrical four-pair cable containing conductive conductors in a film-porous film insulation, twisted into symmetrical pairs with different twisting steps into a common twist, with an external polymer sheath, the insulation of each conductive core is made in the form of a three-layer film-film-foiled film insulation of the same the size over the entire cross section of each conductive core, and the outer film is in contact with the foamed insulation of each conductive core over the entire cross section each conductive core along the entire length of the balanced cable.

The device is illustrated by drawings. In FIG. 1 shows the design of a symmetrical four-pair cable with a three-layer film-film-foiled film insulation of conductors, where

1 - symmetrical pairs;

2 - conductive conductors;

3 - film insulation;

4 - foiled insulation;

5 - an external film;

6 - outer polymer shell.

The core of four symmetrical pairs 1 is located inside the outer polymer shell 6.

In FIG. 2 shows an enlarged construction of a conductive core 2 of a symmetrical cable with a three-layer film-film-foiled film insulation.

In the design of a symmetrical four-pair cable with a three-layer film-film-foamed film insulation of the cores due to the fact that the insulation of each conductive core 2 is made in the form of film insulation 3 over the entire cross section of each conductive core 2, and the film-coated insulation 4 of the conductive core 2 is in contact with the film insulation 3 of each conductive core 2 along the entire cross section of each conductive core 2 along the entire length of the symmetrical cable, the relative dielectric constant of the insulation is significantly reduced and lived. The dielectric constant of the region between the film insulation 3 and the outer film 5, defined by the film-foiled insulation 4, is close to 1.8 (the relative dielectric constant of air is 1). Depending on the size of the corrugations of the film-clad insulation 4, it is possible to change the relative dielectric constant in a fairly wide range, thereby reducing the loss in the dielectric. Since the dielectric constant of the dielectric material is 2.3, taking into account the use of foamed insulation 4 when filling through the holes of its surface between the corrugations in the amount of 20% of the total volume of insulation of the core, we obtain the relative dielectric constant of the entire insulation of the conductive core 2, equal to 1.9 .

Thus, a decrease in the relative dielectric constant of the cable cores is achieved.

In addition to achieving the main technical result, a reduction in dielectric loss and capacitive component of the effect between the pairs is achieved.

Claims (2)

A symmetric four-pair cable containing conductive conductors in a film-porous film insulation, twisted into symmetrical pairs with different twisting steps into a common twist, with an external polymer sheath, characterized in that the insulation of each conductive core is made in the form of a three-layer film-film-foiled film insulation of the same size over the entire cross section of each conductive core, and the outer film is in contact with the film-coated insulation of each conductive core over the entire cross section of each conductive core over the entire length of the symmetrical cable.

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