RU2737966C1 - Symmetrical four-pair cable with film-cord insulation with perforation of contact film of each core - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used in designs of symmetric communication cables for public communication networks and structured cabling systems. Disclosed is a cable comprising strands in film-polymer insulation, twisted into pairs with different pitch of twisting into a common layer, with an outer polymer shell, wherein insulation of each core is made in the form of microtubules of square cross-section of the same size, separated by microcord of arbitrary shape throughout the entire section of each core, wherein the microcords and the microtubes are laid on the perforated microfilm laid on each copper conductor of the cable, and the outer film of the core is in contact with the outer film of the insulation of each core throughout the entire section of each core along the entire length of the symmetrical cable.

EFFECT: invention provides reduced relative permittivity of entire conductor insulation, attenuation factor due to reduction of losses in insulation of cores, wave resistance and capacitance component of influence between pairs, as well as inductance of circuit.

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Description

The invention relates to the field of electrical engineering and can be used in the design of symmetrical communication cables for public communication networks and structured cable systems.

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

Depending on the category of cables for the intended use, different types of core insulation are used: for the cores of category 1 cables, polyethylene with a relative dielectric constant of 2.3 is used; for cables of category 3, a dielectric material is used to insulate the cores also with a relative dielectric constant of 2.3; for cables of category 5e, cellular polyethylene with a sheath is used - film-porous polyethylene with a relative dielectric constant of 2.0; for cables of category 6, Teflon core insulation with a relative dielectric constant of 2.0 is used.

The known design of a four-pair cable, consisting of two fours. Each four is twisted from two pairs. Used film-porous insulation of cores and outer polymer sheath (page 106, Fig. 3.2 6 of the above book). The disadvantage of this design is also the high value of the relative dielectric constant of the core insulation.

The closest in technical essence is the construction of a four-pair cable described in the brochure of Teldor, Wires and Cables, Russia Ltd. 2006, 223 pp. 35 (website: www.teldor.com.). The cable consists of four unshielded twisted (twisted) pairs, twisted together, protected by a PVC sheath for internal fixed installation; core diameter 0.51 mm, polyolefin insulation (film-porous film insulation), outer diameter of insulated core 0.9 mm; outer cable diameter 5.0 mm. Considering the maximum signal propagation speed equal to 0.7 times 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, which the proposed invention is aimed at, is to create such a structure of a symmetrical four-pair cable, which makes it possible to reduce the relative dielectric constant of the cable core insulation, to reduce the capacitance of the pairs and, therefore, the dielectric losses and the capacitive component of the influence between the pairs.

To achieve the technical result in a four-pair cable containing cores in film-polymer insulation, twisted into pairs with different steps into a common layer, with an outer polymer sheath, the insulation of each core is made in the form of square microtubes of the same size, separated by a microcord of arbitrary shape along the entire section of each core, where microcords and micropipes are laid on a perforated microfilm laid on each copper core of the cable, and the outer core film is in contact with the outer insulation film of each core over the entire cross section of each core along the entire length of the symmetrical cable.

The device is illustrated by drawings.

FIG. 1 shows the design of a symmetrical four-pair cable with a tape-core square insulation with perforation of the contact tape of each core. Symmetrical cable 1 contains symmetrical pairs 2, cores 3, perforated contact film 4 of the insulation of each core with perforation 5, a dividing cord 6 of arbitrary shape, micropipes 7 of a square section of the same size along the entire cross section of each core, an outer film 8 of the core insulation in contact with the outer film insulation of the other core, outer polymer sheath 9 of the cable.

FIG. 2 shows an enlarged design of an insulated core of a symmetrical cable with a film-cord square insulation with perforation of the contact film of each core.

It contains a core 3, a perforated contact film 4 of the insulation of each core with perforation 5, a dividing cord 6 of arbitrary shape, micropipes 7 of a square section of the same size along the entire cross section of each core, an outer insulation film 8 of the core.

In this design, due to the fact that the insulation of each core is made in the form of square microtubes of the same size, separated by a microcord of an arbitrary shape along the entire section of each core, and the microcordels and microtubes are laid on a perforated microfilm laid on each copper core of the cable, and the outer film of the core in contact with the outer insulation film of each core over the entire 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 square micropipes, inside which the relative dielectric constant is 1.0 (the relative dielectric constant of air is 1). Depending on the number of micropipes and, it is possible to change the relative dielectric constant of the insulation in a fairly wide range and to reduce the losses in the dielectric. Since the dielectric constant of the dielectric material is 2.3, taking into account the film-microtubular insulation and in contact with the conductors in the volume of 100% of the total volume of the conductor insulation, we obtain the relative dielectric constant of the entire conductor insulation equal to 1.9.

In addition to the main technical result, the attenuation coefficient decreases due to a decrease in losses in the insulation of the conductors, the wave resistance and the capacitive component of the influence between the pairs, and due to the decrease in the thickness of the insulation and, therefore, the distance between the conductors in a pair, the inductance of the circuit also decreases.

Claims (1)

Symmetrical four-pair cable containing conductors in polymeric film insulation, twisted in pairs with different twisting steps into a common layer, with an outer polymeric sheath, characterized in that the insulation of each core is made in the form of square microtubes of the same size, separated by a microcord of arbitrary shape along the entire section of each cores, where microcords and microtubes are laid on a perforated microfilm laid on each copper core of the cable, and the outer core film is in contact with the outer insulation film of each core along the entire cross section of each core along the entire length of the symmetrical cable.

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