RU2714881C1 - Symmetrical four-pair cable with film-microtubular insulation of cores - 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. Symmetric four-pair cable comprises strands in film-polymer insulation, twisted in pairs with different pitching strands, with outer polymer shell, characterized by that insulation of each core is made in the form of microtubes of equal size throughout the entire section of each core, note here that part of microtubes is perforated throughout cable length along symmetrical cable length while outer film contacts microtubular insulation of every conductor over entire section of every conductor along length of symmetric cable.

EFFECT: invention provides reduction of attenuation factor due to reduction of losses in insulation of conductors, reduced wave resistance and capacitive component of influence between pairs, and due to reduction of thickness of insulation and, consequently, distance between strands in pair, inductance of circuit decreases.

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Description

Technical field

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.

State of the art

The known design of four paired 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 dielectric constant of the insulation of the cable conductors.

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.

A known design of four pair cables, consisting of two fours, twisted of two pairs of each four, with film-porous insulation of conductors and an external polymer sheath ("Structured cable systems" authors: A.B. Semenov, S.K. 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 closest in technical essence is the design of a four-pair cable, described in the prospectus of Teldor, Wires and Cables, Russia Ltd. 2006, 223 p. 35 (website: www.teldor.com). The cable consists of four unshielded twisted (twisted) pairs twisted together, protected by a PVC sheath for internal stationary laying; 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 core insulation is 2.0, which is also the main disadvantage of this cable.

SUMMARY OF THE INVENTION

The task to which this technical solution is aimed is to create such a design of a symmetrical four-pair cable that can reduce the relative dielectric constant of the insulation of the cable cores, reduce the capacitance of the pairs and, therefore, the dielectric loss and capacitive component of the influence between the pairs.

To solve the problem in a four-pair cable containing conductors in film-polymer insulation, twisted in pairs with different twisting steps in a general twist. With an external polymer sheath, the insulation of each core is made in the form of microtubes of the same size over the entire cross section of each core, and some microtubes are perforated, and the outer film is in contact with the microtubular insulation of each core over the entire cross section of each core along the entire length of the symmetrical cable.

List of figures

The device is illustrated by drawings. In FIG. 1 shows the design of a symmetrical four-pair cable with film-microtubular core insulation. It contains: symmetrical pairs 1, cores 2, microtubular insulation of the core 3, the outer film 4 of the insulation of the core in contact with the microtubular insulation 3, the outer polymer sheath of the cable - 5.

In FIG. 2 shows an enlarged design of an insulated core of a symmetrical cable with a film-microtubular insulation of conductors. It contains a core 2, microtubes along the entire cross section of the core 2, perforated microtubes 6, an outer film of insulation of the core 4 in contact with microtubes along the entire cross section of the core along the entire length of the symmetrical cable.

The implementation of the invention

In the design of a symmetrical four-pair cable with a film-microtubular insulation, the insulation of each core 2 is made in the form of microtubes along the entire cross section of each core, and some microtubes are perforated 6, and the outer film 4 is in contact with the microtubular insulation 3 of each core 2 the entire cross section of each core along the entire length of the symmetrical cable, the relative dielectric constant of the core insulation is significantly reduced due to microtubes, inside which the relative dielectric constant is 1.0 ( relative dielectric constant of air is 1). Depending on the number of microtubes and perforated microtubes, the relative permittivity can be varied over a fairly wide range, reducing the thickness of the insulation and reducing losses in the dielectric. Since the dielectric constant of the dielectric material is 2.3, taking into account the film-microtubular insulation when filling through the microtubes through holes and in contact with the cores in the amount of 100% of the total insulation volume of the core, we obtain a relative dielectric constant of the entire insulation of the core equal to 1.9. As a result, the attenuation coefficient decreases due to the reduction of losses in the core insulation, the wave resistance and capacitive component of the influence between the pairs, and due to the decrease in the insulation thickness and, therefore, the distance between the wires in the pair, the circuit inductance also decreases.

Claims (1)

Symmetric four-pair cable with film-microtubular insulation of conductors, containing conductors in film-polymer insulation, twisted in pairs with different twisting steps into a common twist with an external polymer sheath, characterized in that the insulation of each core is made in the form of microtubes of the same size over the entire cross section of each cores, and some microtubes are perforated along the entire cross section of the core along the entire length of the symmetrical cable, and the outer film is in contact with the microtubular insulation of each core along the entire section of each core along the entire length immetrichnogo cable.

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