CS274071B1 - Method of coaxial cables' outside core production and equipment for realization of this method - Google Patents

Abstract

Improvement of electrical and mainly of transfer parameters of coaxial cables, as well as mechanical properties of these cables with the use of a new technology of production of their outer core on a continuous production line. The principle of the solution consists in forming of the inner metal plated plastic foil on the cable core, laying the thin metal wires led in guide openings of a circular guide that are meandered and deposited in the direction of tangent on the surface of the inner foil as a result of turning the guide in the range of +- 270 degrees vertically to the axis of the cable core and in the depositing the outer metal plated plastic foil with overlapping borders. The outer core of the cable is produced by means of a device that consists of two coating calibres (1, 6) that have the form of a hollow truncated right circular cone, two wiping calibres (2, 7) connected with temperature regulators (21, 71), circular guide (3), controlled by rotation regulator (31), while on the circular guide (3) there is a centre hole (32) and at least three guiding holes (33) connected with the perimeter of the circular guide (3) by means of indentures (34). Furthermore it consists of a set containing a guide (4) with forming tooth (41) and leading pulley (5). Behind the first coating calibre (1), in the distance (L), which equals 0 to 10 D there is the first wiping calibre (2). Behind it, in the plane perpendicular to the retracted cable core, there is a rotating circular guide (3) with slewing range of +- 270 degrees, behind which, off the cable core axis, there is the guide (4) and the leading pulley (5). Behind the circular guide (3) in the cable core axis in the distance (L') corresponding to the length of the required meander-like bending of the thin wires, there is the second wiping calibre (6) and behind it, in the distance (L), there is the second coating calibre (7).<IMAGE>

Description

(54)

Method for manufacturing an outer core of coaxial cables and apparatus for performing this method

CS 274071 B1 'Improvement of the electrical, in particular transmission, properties of coaxial cables as well as the mechanical properties of these cables by a new technology of their outer core production on a continuous production line. The essence of the solution is to form the inner metallized plastic foil on the cable core, the placement of metal wires, guided through the guide holes of the circular guide, which are rotated by up to + 270 ^° perpendicular to the cable core meandering and laid tangentially on the inner foil surface. depositing an outer metallized plastic film with overlapping edges. The outer core of the cable is formed by a device consisting of a hollow truncated rotary cone (1, 6), a sheath of ironing calibers (2, 7) connected to temperature regulators (21, 71), a circular guide (3) controlled by the regulator of a rotation (31), wherein a central hole (32) and at least three guide holes (33) connected to the circumference of the circular guide (3) by notches (34) are formed on the circular guide (3). It further comprises a system formed by a guide (4) with a forming tooth (41) and a guide roller (5). Behind the first lining gauge (1) is located at a distance (L) equal to 0 to 10 0 the first ironing gauge (2), followed by a circular guide (with a rotation range of + 270 °) in a plane perpendicular to the pulled cable core. 3), behind which the guide (4) and guide pulley (5) are located outside the cable core axis. A second ironing caliber (6) is located behind the circular guide (3) in the cable core axis at a distance (L ') corresponding to the length of the desired meander ripple of wires and behind it at a distance (L) a second caliper (7).

Fig. 1

CS 274071 Bl

BACKGROUND OF THE INVENTION The present invention relates to a method for manufacturing an outer core of coaxial cables with increased cable shielding efficiency and to an apparatus for performing this method. The purpose of the solution is to increase the productivity of the production of coaxial cables and to improve their electrical, especially transmission, and mechanical properties by a new technology of their production.

Of the existing known methods for producing the outer core of coaxial cables, the most commonly used are solutions that are based on forming the core from a regular braid by wires whose density and pitch determine the size of the cable shield. The braiding is done as a separate operation by conventional braiding machines. The disadvantage of these methods is the slow speed of this part of the manufacturing process - in the range of 1-3 m / min, which cannot be increased, because at higher speeds the thin wires break and tear. Due to the slowness of the braid manufacturing operation (repairs, windings of new spools, etc.), it is not possible to apply a sheath in tandem because the extrusion during sheathing is a continuous operation over a certain length and requires at least one order of higher speed. Moreover, the shielding efficiency of the outer core thus formed is not very good. Although a higher screening efficiency can be achieved by combining the longitudinally clad film and the thin braiding of the wires, the productivity of such a manufacturing operation remains low. In a further group of existing coaxial cable production methods, the productivity of production is already substantially increased by making the outer core at the same time as the sheath, i.e. the manufacturing operations run at the same speed, the outer core being metallized plastic foils with parallel ties. in particular for cable connector, but for more demanding applications of coaxial cable, such a technology does not sufficiently shield the transmitted RF signal from the surrounding electromagnetic interference. The inner metallized plastic foil, longitudinally clad and overlapped, is not electrically conductively connected at the folding point, nor does the outer foil have an electrical conductive contact in the miffite. Although the metallized plastic films are deposited together with the metal layer, reliable electrically conductive bonding of the layers does not occur at high frequencies, in particular due to the proximity phenomenon and the thin surface layer of alumina. This unfavorable state is most evident at the point of folding of the foils where the metal layers are separated by plastic. The minimum coupling impedance values on the cables are thus at 30 to 30 mJ / m at 30 MHz. Compared to the previous solutions, a significantly better and so far the highest shielding efficiency is achieved with cables whose shielding is produced in a manner in which the backsheet is ironed with a copolymer directly to insulate the cable and so-called outer sheathing. With a fold that ensures good conductive bonding of the film and closure of the outer core from interference from the surrounding cable. One of the disadvantages of the method of the outer core so formed is that the film needs to be melted on the casing in some cases, as a result of which it is necessary to use a melting material capable of being used as the tape carrier material, thereby greatly narrowing the range of usable materials. Another disadvantage is the use of braid of wires between the foils, which puts this coaxial cable production at the level of conventional cable production with braided outer core. The major disadvantages of existing devices are that the entire coaxial cable manufacturing process cannot be carried out continuously, by the sequence of individual operations at the same production process speed. The cladding gauges used in the apparatus are designed to clad metal foils, i.e. the foil with memory stability is not suitable for plastic metallized foils.

The above-mentioned disadvantages of the prior art are eliminated by the solution according to the invention, which is based on the fact that the cable core is in the first cladding caliber! molds the inner plastic foil with a metal layer outwardly while overlapping its edges, and the cable core thus wrapped is fed to an ironing gauge in which the foil is thermoformed into a tube shape. Then the wrapped cable core is guided through the center of the circular guide and through its guide holes are simultaneously guided metal wires, which are rotated by up to - 270 ° perpendicular to

CS 274071 B1 of the cable core meandering undulatingly and placed in the tangent direction on the surface of the inner metallized plastic film. The partially shielded cable core then passes through the second lining caliber where the outer metallized plastic foil is deposited on the metal inwardly. Its edges coincide with the deposition on the side opposite to the overlap of the inner foil, whereby the inner edge of the metallized plastic foil is rotated by a metal layer 180 ° overlap twice the overlap length prior to the deposition. Subsequently, the shielded cable core is fed to a second iron-on gauge, in which the outer metallized plastic foil is shaped in shape after heating. Further, the outer core of the coaxial cable is formed by a device comprising two lining gauges, two ironing gauges, a circular guide, a forming tooth guide and a guide pulley, the first and second lining gauges having the shape of a hollow truncated a rotary cone, the edges of the shell of which are folded into the through-slot, and the circular guide has a center hole 3 to 5 D in the center and at least 0.5 to 50 from the center hole equally spaced at least three guide holes connected to the circumference oblique to the wiring direction of wires. The ironing gauges are connected to the temperature regulators and the circular guide to the rotation regulator. The whole line is arranged so that the first ironing gauge is placed behind the first lining gauge at a distance L equal to 0 to 10 D, preferably 0.5 to 5 D, behind it is rotatable in a plane perpendicular to the hauled cable core with a rotation range of - 270 ° a circular guide is placed behind which the cable core and the guide pulley are located outside the cable core. A second ironing caliber is placed behind the circular guide in the cable core axis at a distance L 'corresponding to the length of the desired meander corrugation of wires and behind it at a distance L a second lining caliber.

The advantages of the solution according to the invention are manifested in particular in the possibility of significantly increasing the speed of the production process of the coaxial cables, while at the same time achieving a high homogeneity of the outer core. The production speed makes it possible to combine the formation of the outer core with the extrusion of the sheath in one operation, thus eliminating the in-process shifting of the coaxial cable blank, occupying limited space in cable operations, and the like. Compared to the production of conventional braided cables, the coaxial cable production speed is several times higher while achieving better cable shielding properties. The mechanical properties of the outer core of metallised plastic foils are also markedly superior to those of the metal foil core, since the cold-formed metal foils, for example at bends, become brittle and break even later. The advantages of the proposed device consist mainly in the fact that it enables relatively simple ways of sweeping the wires between the foils, controllable size of their corrugation, their uniform placement, while solving the problem of wires falling out of the guide holes during the guide rotation and possibility to regulate the stopping time before turning to the opposite. direction. The design of the ironing gauges and their heating to the desired temperatures allows the coated plastic foils to lose their original shape stability, to form into the required shape and to permanently overlap their edges until final fixation by applying the sheath in the head of the extruder.

In the accompanying drawings, FIG. 1 schematically shows a continuous line for producing the outer core and sheath of coaxial cables with increased shielding efficiency, FIG. 2 is a detail view of a circular guide, and FIG. 3 is a detail view of a guide with a forming tooth. In FIG. 1 shows a first lining caliber 2 ^{with a} through slot 21, ^behind which a first ironing caliber 2 is connected at a distance 2 with a temperature regulator 21, and a circular guide 2 ^with a rotation regulator 32 is placed downstream of the ironing caliper 2. a groove 61, located at a distance L * behind the ring guide 2 ^and off-axis a toothed guide 41 with a shaping tooth 41 and a guide roller 2. A second ironing caliber 7 with a temperature controller 71 and a head j) 274071 Bleaching machine. In FIG. 2 is a detail of a circular guide 2 ^{with a} central bore 32, guide bores 33 and sloped notches 34. In FIG. 3 shows a guide 2 ^{with a} shaping tooth 41.

The solution is further illustrated by examples of a specific embodiment of the invention.

Example 1

The cable core of diameter D = 3.7 mm is fed into the lining caliber, where it is placed on it an aluminum metallized polyethylene terephthalate foil, width 15 mm, with a metal layer we rom out. The tapered neck of the cladding caliber with a through slot overlaps the edges of the foil at a width of 2 mm. The wrapped cable core is then passed through a heated ironing caliber in which the memory stability of the foil is removed at 150 ° C and the foil is formed into a tube shape. The foil-wrapped cable core is guided perpendicularly through the central opening of the circular guide, whose bundles containing three tinned copper wires of 0.15 mm diameter are simultaneously guided through the eight guide openings. The circular guide, controlled by electric drive and set on a 150 mm wave period, rotates through - 180 ° in a direction perpendicular to the cable core axis, with a pause before reverse of 0.5 s at a production speed of 20 m / min. tangentially deposited on the surface of the inner film. The angled slots to the guide holes allow easy insertion of the wires into the holes, but at the same time prevent them from falling out of these holes when the circular guide is rotated. The partially shielded cable core then passes into a second lining caliber, which is simultaneously fed with an outer aluminum metallized polyethylene terephthalate foil of a width of 20 mm, through a forming tooth guide and a guide pulley directed by the metal side of the bottom. The inner edge of the interleaved film is rotated in the opposite direction by 2 mm before being introduced into the lining caliber. In the lining caliber, at the same time as the outer film is deposited, its edges overlap to an overlap width of 2 mm on the opposite side to that of the inner film. The shielded cable core is then fed to a second ironing gauge in which the outer foil is fixed in the shape of a tube at a temperature of 160 ° C and the outer core thus formed above the cable core is routed to the extruder head where it is applied over the sheath.

Example 2

The device for producing the outer core of coaxial cables with increased cable shielding efficiency together with the cable sheathing extruder forms a continuous line at the beginning of which is built the first lining caliber 2 ^{with an} internal diameter IB mm on the inlet and an internal diameter 4.0 mm outlet part, with a through slot

11. A first ironing caliber 2, an internal diameter of 4.1 mm, is connected to the temperature controller 21 at a distance of 3 mm. A circular guide 2 is mounted downstream of the first ironing caliper 2 and is rotatable in a plane perpendicular to the draw-off! cable core, with rotation range up to - 180 °. Its rotation is regulated by the electric rotation regulator 31 depending on the selected production speed and the selected crimping size; The circular guide 1 has a central bore 32 of 10 mm diameter and at a distance of 4 mm from the central bore 32 has regularly spaced eight 2.5 mm diameter bores 33 on the circle, which are connected by a diagonal notch 34 to the circumference of the circular guide 2. outside the cable core axis there is a guide 4 with a shaping tooth 41 of 2 mm and a guide pulley 5.

, 150 mm beyond the circle guide 2 ^e j disposed facing the other £ gauge internal diameter at the inlet of 18 mm and the internal diameter of the outlet portion

4.5 mm, with a through slot 61. A second ironing caliber 2 ^{with an} inside diameter of 4.6 mm is connected at a distance of 5 mm downstream of the second tiling gauge 6, connected to a temperature controller 22. The white head j) is healed.

Rushes can be used in cable ties in the production of cooxial cables with increased shielding efficiency.

Claims (2)

SUBJECT INVENTION Method for producing an outer core of coaxial cables with increased cable shielding efficiency, characterized in that the cable core first passes through a first lining caliber in which the inner metallized flat foil is formed on it with the metal layer outwardly while simultaneously overlapping its edges, coated spirit of the cable leading to the iron-gauge, wherein the metallized plastic film heat make molds to the shape of the tube, subsequently coated spirit of the cable passes through the center of the circular guide, the guide holes are simultaneously kept metal drůtiký to rotation of the guides and the - 270 ⁰ perpendicular to the axis the cable cores meanderly corrugate and deposit tangentially on the surface of the inner metallized plastic film, and the partially shielded cable core then passes through the second cladding caliber where ea is deposited on the outer metallised plastic foil by metal in the bottom so that its edges coincide on the opposite side to that of the inner metallized plastic film, wherein before inserting the inner edge of the metallized plastic film, the metal layer is rotated 180 ° in the overlap direction in the length of twice the overlap, and subsequently the shielded cable core is routed to a second the outer metallised plastic foil fixes after heating. 2. Apparatus according to claim 1, characterized in that it extends from a first hollow truncated caliper (1) in the form of a hollow truncated rotary cone, the edges of which are folded into a through slot (11), from a first ironing caliber (2) provided with a temperature regulator. (21) and positioned at a distance (L) equal to 0 to 10 0, preferably 0.5 to 50 0 after the first lining gauge (1), of a circular guide (3) rotatably mounted in a plane perpendicular to the cable cable being pulled, a rotation of up to -270 °, controlled by a rotation regulator (31), which circular guide (3) has a centrally-formed bore (32) having a diameter of 3 to 50 and equidistantly spaced from 0.5 to 50 from the central bore (32) at least three guide holes (33) connected to the circumference of the circular guide (3) by notches (34) oblique to the wiring direction, from the second facing gauge (6), also in the form of a hollow truncated rotary cone, the edges of the sheath being folded into a through slot (61) located at a distance (L ') corresponding to the length of the desired meander ripple of the wires behind the circular guide (3), before which lining gauge (6) is located outside the cable core 4) with a shaping tooth (41) and a guide pulley (5), and a second ironing gauge (7) with a temperature controller (71), located at a distance (L) after the second lining gauge (6).