SU1749917A1 - Flexible high-frequency electric cable - Google Patents

Abstract

Usage: in electrical engineering, in particular in cable technology. Summary of the invention: in order to improve cable resistance to multiple bends, the ratio of twisting steps of shielded pairs to twisting pitch lived in a pair and to twisting pitch wires in the conductor are selected intact and equal and lie in the interval from 8 to 18. 1 d., 3 tab.

Description

The invention relates to electrical engineering, in particular, to cable technology, and can most effectively be used in a flexible flexible cable for transmitting information to computer complexes of excavation equipment, mobile curb receptacles; machine tools with software-controlled control A shielded cable is known with two coaxial pairs enclosed in a common sheath, the outer conductors of which are made of longitudinally superposed conductive tapes, the edges of which are connected along one surface, and the insulation of the pairs from one another is made of longitudinally imposed insulating tape three, the width of the insulating tapes of the outer conductors and the edges of each tape are bonded to each other along one surface.

The disadvantage of this design lies in the instability of the electrical parameters due to the presence of air inclusions between the tapes, the longitudinal extension of the insulating and conductive tapes cannot ensure the resistance of cables to

repeated mechanical deformations (for example, bending).

The closest in technical essence and positive effect is a high-frequency communication cable containing two twisted pairs placed in screens (round shape), and two non-twisted pairs consisting of parallelly laid veins, also placed in screens. Both twisted and parallel-laid pairs have a clear insulation under the CES. The screen of non-twisted bar has an ellipse shape with the size of the major axis equal to the diameter of the screen of twisted pairs, and the ratio of semi-axes is 0.60.

A disadvantage of the known cable lies in the fact that the longitudinal arrangement of the non-twisted insulated conductors and the ellipsoid form of the screen in a flat symmetrical pair, which has a lower geometric stability, do not provide the necessary resistance of the cable to mechanical deformation (bending, rewinding, etc.), which reduces operational reliability cable

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The purpose of the invention is to increase the operational reliability of the cable by improving its resistance to multiple bends.

This goal is achieved by the fact that in a flexible electric high-frequency cable containing twisted shielded symmetric pairs of twisted insulated multiwire conductive wires with the same direction of twisting the wires in the windings, the relationship of the twist pitch of the shielded pairs to the twisting steps of the isolated veins in a pair and to the step of twisting the wires in the vein are equal to integers and lie in the range from 8 to 18.

The drawing schematically shows the proposed cable.

The cable contains copper conductor 1 made of MM wire, insulation 2 made of polyethylene, screen 3 made of tinned copper wire superimposed along a twist of insulated conductors in a pair, PET-E 4 film made on a common twisted shielded pair, protective sheath 5 superimposed PET-E films.

Example. Twisted pair cables were manufactured having 2, 4, 8, 16 twisted pairs, each pair of wires was in an individual screen of tinned copper wires with a diameter of 0.12 mm, cores of 0.35 mm2 of copper wires of the MM brand with a diameter of 0.26 mm, at least 4 classes of flexibility, insulated with cable insulating polyethylene and twisted into a pair. The direction of twisting the wires in the core, the insulated conductors in a pair, and the shielded pairs in the cable are unilateral - left. In all structures, the pitch of the conductive wires is 11.2 mm, the pitch of the insulated conductors in a pair is 21.7 mm; the twisting factor of insulated conductors in a pair is 1.037; the ratio of the twisting pitch of insulated conductors in a pair to the twist pitch of conducting conductors is 2.

The ratio of the twist pitch of the shielded pairs to the twist pitch of insulated conductors in a pair for 2.4, 8, 16 paired balanced cables is 4, 5, 6, 9, respectively, and to the twist pitch of conducting conductors, respectively, 8, 10, 12, 18. The actual steps of twisting the shielded pairs are respectively 81.9; 103.5; t24.3; 187.4 mm. Coefficient of twisting, defining some physical increase in the length of the pair in the cable during the corresponding steps: 1,059; 1.047; 1.048; 1.042. Behind

counting the ratio of the selected twisting steps of the structures (in the total cable twist step there is an integer number of pairs; in the twist step of the pair, an integer number of pairs; in step

twist pairs - an integer number of steps. twisted cores) cables have increased operational reliability.

To compare the cable resistance to repeated bending, a symmetric high-frequency cable was manufactured with four shielded pairs in three versions (Table 1).

Tables 2 and 3 show the nominal dimensions and technological modes of manufacture of the proposed cable (option II). Cables are tested for resistance to repeated bending deformations of ± ± 2 rad with a bend radius of 150 mm. The number of cycles is 150000. The following results were obtained: when the ratio of twisting steps is 4.8 and 9.6, a screen abrasion is observed, the destruction of current-carrying veins is 20%, the shell and insulation have no damage, when the ratio of steps is 5.0 and 10, 0 - shell, shields, insulation and conductive veins have no damage, with a ratio of twisting steps of 5.6 and 11.2, the screen is destroyed - 20%, the shell is worn, the destruction of conductive veins is 30%, the insulation is without damage.

Thus, high mechanical characteristics are provided by the ratio of the chosen steps of the twist of the structure, namely, in the general step of twisting the cable.

contains an integer number of pairs twisting steps; in the twisting step of a pair, an integer number of twisting steps of the core. With this ratio, the flexibility of the cables and the resistance of the cables to free bending increase.

Claims (1)

Claims of the invention A flexible high-frequency electric cable containing twisted shielded symmetrical pairs twisted insulated multiwire conductive veins with the same direction of twisting wires, characterized in that, in order to increase the operational reliability of the cable by improving its resistance to repeated bends, the ratio of twist pitch of shielded pairs to twisted pitch of insulated conductors in a pair and to the twist pitch of the wires in the conductor equal to integers and lie in range from 8 to 18. Table 1 Wl "e.J5) 7xO, Z4 0.78 0, S I.I M," 5 Malomeiiv film iovotov life eovi tsmo with enamel meme shell ..-.-..- ". 1 5m $ KG" 5YI K5L "1S912 l 1 5..v92v1V m1 ... Twist m / m Nale Isolation j Twist iolithromy I Parma shielding I Overall twist screen pair II nmroyinc p n I | updates ppvik y PZT-E 11.2 s growth Extra / viomnai line Hf-1-60  Pitchfork 0,79 in Diameter and pitch 1.8 AI Toltsik and ol cmm 0.5 mi  speed of 100 m / nm Sig "p a nrutil" c st St Vag 21 (7 n ibmm K “L AGMIN“ ekrutA MvAnLA SPEED 10.v m / iii Stage mr ktch “IIIR 4 Editor N. Dumbass Compiled by, Kevroleva Tehred M. Morgenthal Table 1 1 ("1.03 9.86 I, on 1,037 1, i.s i, l Table} Ma / ToxtHtNi Obolimm Opl "toii" and "" them NAG skrutm1 105.5 and & t "| gs- b 6 10.5 16 LRYaTSVA I1 IODINE CRpytKM mango prf opohm dnaetroi 0, obiotkm tribe according to PRMDEA “about PET-3 DI 50 IN yino proteaopolok J6.6 im My corrections to the Ground Harness Braid 18. rf, 5Calculated n pc “ovTt“ thirty AtHttSnan speed 17.55 and / or Proofreader E. Lonchakov