WO2018040637A1 - Leaky coaxial cable and manufacturing method thereof - Google Patents

Abstract

Provided are a leaky coaxial cable and a manufacturing method thereof. The leaky coaxial cable sequentially comprises, from inside to outside: an inner conductor (1); an insulation layer (2); an outer conductor (3); and a sheath (4). The inner conductor (1) is made of an electrically-conductive tubing material. The insulation layer (2) encloses the inner conductor (1). The insulation layer (2) is made of a high temperature-resistant material having a high dielectric constant. The outer conductor (3) encloses the insulation layer (2). The outer conductor (3) is made of an electrically-conductive strip. The sheath (4) encloses the outer conductor (3). The sheath (4) is made of an oxidation-resistant and high temperature-resistant material. The leaky coaxial cable has high temperature resistance, is extremely flexible, and can function stably in a high temperature environment for a long time while maintaining good mechanical performance.

Description

Leaky coaxial cable and preparation method thereof Technical field

The invention relates to the field of communication transmission, and in particular to a leaky coaxial cable and a preparation method thereof.

Background technique

Leaky coaxial cable is a special antenna used in underground mobile communication system to improve electromagnetic wave propagation characteristics. It has both transmission characteristics and antenna radiation characteristics, can overcome underground strong electromagnetic interference, and solves high-frequency wireless signals. The problem that the tunnel space cannot be naturally transmitted. At present, in addition to the wireless communication coverage of railways, tunnels, mines and other places, the cable leakage is widely used in security, detection and sensing, etc., and the development prospect is very broad.

The traditional leaky coaxial cable generally includes an inner conductor, an insulating layer, a punched copper tape wrap or a longitudinal outer conductor and an outer sheath from the inside to the outside, wherein the insulating layer is usually composed of physical foamed polyethylene, and the temperature is resistant. Poor performance, only about 85 degrees, can not meet the needs of high temperature environment.

Secondly, with the development of 5G, elevators and indoor wireless cabling are a development trend, and the demand for ultra-softening of leaky coaxial cables is increasing. The existing indoor leaky coaxial cables on the market are mostly 50-12 specifications, and the flexibility is poor. Unable to meet the need for flexibility in indoor coverage.

Summary of the invention

In view of the above, it is necessary to provide a highly flexible leaky coaxial cable that can withstand high temperatures and a method of preparing the same.

One aspect of the present invention provides a leaky coaxial cable, which is an inner conductor, an insulating layer, an outer conductor and a sheath from the inside to the outside, and the inner conductor is composed of a conductive pipe, characterized in that the insulating layer is wrapped in Outside the inner conductor, the insulating layer is composed of a high dielectric constant high temperature material, the outer conductor is wrapped outside the insulating layer, the outer conductor is composed of a conductive strip, and the sheath is wrapped around the outer conductor, the sheath It is composed of an oxidation resistant high temperature resistant material.

Another aspect of the present invention provides a method for preparing the above leaky coaxial cable, comprising the following steps:

(1) extruding, pushing or wrapping a high dielectric constant high temperature resistant material on an inner conductor to form an insulating layer, the high dielectric constant high temperature resistant material being polytetrafluoroethylene, polyperfluoroethylene propylene At least one of an ethylene-tetrafluoroethylene copolymer and polyvinylidene fluoride;

(2) Winding the conductive strip on the insulating layer by means of gap-woven galvanized copper wire, galvanized copper-clad steel wire, silver-plated copper wire or silver-plated copper-clad steel wire, or wrapping the conductive tape in a package or Laying the slotted copper strip vertically over the insulating layer to form an outer conductor;

(3) Forming a sheath on the outer conductor by wrapping or extruding the oxidation resistant high temperature resistant material.

The leaky coaxial cable provided by the invention has the characteristics of high temperature resistance and ultra-softness, and is suitable for special occasions with high temperature requirements of 200 ° C and above, in particular, can work stably in a high temperature environment for a long time, and maintain good mechanical properties. .

DRAWINGS

1 is a schematic structural view of a leaky coaxial cable according to Embodiment 1 of the present invention.

2 is a cross-sectional view showing a leaky coaxial cable according to Embodiment 1 of the present invention.

3 is a cross-sectional view showing a leaky coaxial cable according to a third embodiment of the present invention.

Main component symbol description

Inner conductor	1
Insulation	2
Outer conductor	3
jacket	4
Spiral wrinkles	5
Slot	6,8
Identification line	7

The invention will be further illustrated by the following detailed description in conjunction with the accompanying drawings.

detailed description

The present invention may be embodied in a different form of embodiment, and the drawings and the description herein are intended to be an embodiment of the invention, and are not intended to limit the invention to the illustrated figures and/or the specific embodiments described. in.

One aspect of the present invention provides a leaky coaxial cable, which is an inner conductor, an insulating layer, an outer conductor, and a sheath from the inside to the outside, and the inner conductor is composed of a conductive pipe, and the insulating layer is wrapped around the inner conductor. The insulating layer is composed of a high dielectric constant high temperature material, the outer conductor is wrapped outside the insulating layer, the outer conductor is composed of a conductive strip, the sheath is wrapped outside the outer conductor, and the sheath is resistant to oxidation Made of high temperature resistant materials.

The leaky coaxial cable provided by the invention has the characteristics of high temperature resistance and ultra-softness, and is suitable for special occasions with high temperature requirements of 200 ° C and above, in particular, can work stably in a high temperature environment for a long time, and maintain good mechanical properties. .

According to an embodiment of the invention, the high dielectric constant refractory material is a refractory material having a dielectric constant of less than 3, including but not limited to polytetrafluoroethylene, polyperfluoroethylene propylene, ethylene-tetrafluoroethylene copolymerization. And at least one of polyvinylidene fluoride.

Preferably, the high dielectric constant refractory material is polytetrafluoroethylene.

According to an embodiment of the invention, the insulating layer has an outer diameter of 0.1 to 7 mm.

Preferably, the outer diameter of the insulation is 3.5 to 7 mm.

The leaky cable provided by the invention has a small outer diameter of the insulation, and can ensure that the bending radius thereof does not exceed 100 mm, which is only half of the bending radius of the leaky coaxial cable for the conventional indoor covering, and the limit bending radius is not more than 80 mm, and has good flexibility. Performance to meet the needs of existing wireless cabling.

According to an embodiment of the invention, the inner conductor is composed of a conductive tube which is a tubular or linear conductive material, the tubular conductive material comprises a hollow tube or a solid tube, including silver plated copper wire, silver plated At least one of a copper clad steel wire, a solid copper wire, and a copper pipe.

According to an embodiment of the invention, the electrically conductive tube of the inner conductor is embossed to form a spiral wrinkle.

According to an embodiment of the invention, the inner conductor has a diameter of 2 to 3 mm.

According to an embodiment of the invention, the outer conductor is composed of a conductive strip which is wrapped, longitudinally wrapped or woven by a strip-shaped conductive material, the conductive strip being a strip or a wire braid The conductive material comprises at least one of a galvanized copper wire, a galvanized copper clad steel wire, a silver plated copper wire or a silver plated copper clad steel wire and a copper tape.

According to an embodiment of the invention, the outer conductor has a thickness of 0.05 to 0.2 mm.

According to an embodiment of the invention, the electrically conductive strip is provided with at least one slot of a vertical structure. The vertical shape includes, but is not limited to, a geometry that is longer than the width, including but not limited to a long strip or an arc.

According to an embodiment of the invention, the arc slot has a slot length of 8 to 12 mm, an arc of 4 to 6 degrees, a slot pitch of 240 to 260 mm, and a slot width of 1.6 to 2.6 mm.

According to an embodiment of the invention, the elongated slot has a slot length of 8 to 12 mm, a slot pitch of 240 to 260 mm, and a slot width of 1.6 to 2.6 mm.

According to an embodiment of the invention, the outer surface of the sheath is provided with a sheath marking line.

According to one embodiment of the invention, the oxidation resistant refractory material has excellent oxidation resistance including, but not limited to, polyperfluoroethylene propylene.

Another aspect of the present invention provides a method for fabricating the above-described leaky coaxial cable, comprising the following steps:

(1) pushing, extruding or wrapping a high dielectric constant high temperature resistant material on an inner conductor to form an insulating layer, the high dielectric constant high temperature resistant material being polytetrafluoroethylene, polyperfluoroethylene propylene At least one of an ethylene-tetrafluoroethylene copolymer and polyvinylidene fluoride;

(2) Winding the conductive strip on the insulating layer by means of gap-woven galvanized copper wire, galvanized copper-clad steel wire, silver-plated copper wire or silver-plated copper-clad steel wire, or wrapping the conductive tape in a package or Laying the slotted copper strip vertically over the insulating layer to form an outer conductor;

(3) Forming a sheath on the outer conductor by wrapping or extruding the oxidation resistant high temperature resistant material.

According to an embodiment of the present invention, the pushing in the step (1) comprises sufficiently stirring a high dielectric constant high temperature resistant material and an auxiliary oil, and then putting it into a ripening cabinet for curing, and the matured mixture passes through The binder control box is pressed into the acrylic tube, the mixed slurry in the acrylic tube is poured into the pusher cylinder, placed in the inner conductor, and then the mixture is coextruded with the inner conductor to form an inner conductor with an insulating layer. The proportion of the auxiliary oil is 16% to 22%, and the auxiliary oil is 90# solvent oil.

As is known to those skilled in the art, the extrusion method in the step (3) is carried out by means of screw extrusion.

As will be appreciated by those skilled in the art, the aging is to condense the high temperature material at a set temperature of 30 to 40 °C.

According to an embodiment of the present invention, the pusher uses a brake pressure of 6 to 10 MPa and a vulcanization temperature of 190 to 220 ° C for co-extruding the mixture with the inner conductor.

According to an embodiment of the present invention, the wrapping in the step (1) is to wrap the 2-3 layers of the high dielectric constant refractory material without gaps. As will be appreciated by those skilled in the art, the winding in the step (2) and the step (3) can also be carried out in the same manner as in the step (1).

According to an embodiment of the present invention, the slit woven galvanized copper wire, the galvanized copper-clad steel wire, the silver-plated copper wire or the silver-plated copper-clad steel wire in the step (2) is formed by plating a plurality of wires. Zinc-copper wire, galvanized copper-clad steel wire, silver-plated copper wire or silver-plated copper-clad steel wire are wound on the insulation layer according to the required weaving density, each galvanized copper wire, galvanized copper-clad steel wire, silver-plated copper The gap between the wire or the silver-plated copper clad steel wire is controlled by the weaving density to control the lateral radiation performance of the final product.

According to an embodiment of the invention, the weaving density is from 60% to 75%.

According to an embodiment of the present invention, the step of wrapping the wrapped copper strip in the step (2) is to vertically or wrap the slotted copper strip on the insulating layer, and according to the The required lateral radiation performance requirements are designed with different slotted structures.

Preferably, the method of vertically wrapping the copper strip further comprises: micro-rolling the slotted copper strip, and longitudinally lapging on the insulating layer, and designing different according to required lateral radiation performance requirements. Slotted structure.

According to an embodiment of the invention, the slotted structure is a vertical structural slot. The vertical shape includes, but is not limited to, a geometry that is longer than the width, including but not limited to curved slots or elongated strips.

According to an embodiment of the invention, the step (3) further comprises providing an identification line on the sheath.

According to one embodiment of the invention, the oxidation resistant refractory material has excellent oxidation resistance including, but not limited to, polyperfluoroethylene propylene.

Embodiment 1

Referring to Figures 1 and 2, a leaky coaxial cable includes an inner conductor 1, an insulating layer 2, an outer conductor 3, and a sheath 4 in this order from the inside to the outside.

The inner conductor 1 is composed of a 2.6 mm copper tube and the inner conductor 1 is embossed to form a spiral wrinkle 5 on the surface.

The insulating layer 2 is wrapped on the outside of the inner conductor 1, and the insulating layer 2 is formed by extrusion of polytetrafluoroethylene, and the outer diameter of the insulating layer 2 is 6.5 mm.

The outer conductor 3 is wrapped outside the insulating layer 2, and the outer conductor 3 is formed by a longitudinally wrapped copper strip. The outer conductor 3 is further provided with at least one slot hole 6 which is an arc-shaped slot hole having a length of 9 mm, an arc of 5 degrees and a width of 2 mm. When there are a plurality of slots 6, the slot 6 has a pitch of 245 mm. The outer conductor 3 has a thickness of 0.1 mm.

The sheath 4 is wrapped around the outer conductor 3, and the sheath 4 is formed of a polyperfluoroethylene propylene wrap. The outer surface of the sheath 4 is also provided with an identification line 7.

Embodiment 2

A leaky coaxial cable includes an inner conductor 1, an insulating layer 2, an outer conductor 3, and a sheath 4 in this order from the inside to the outside.

The inner conductor 1 is composed of a 2.4 mm copper tube and the inner conductor 1 is embossed to form a spiral wrinkle 5 on the surface.

The insulating layer 2 is wrapped on the outside of the inner conductor 1, and the insulating layer 2 is formed by extrusion of polyperfluoroethylene propylene. The outer diameter of the insulating layer 2 is 6.0 mm.

The outer conductor 3 is wrapped outside the insulating layer 2, and the outer conductor 3 is formed by a longitudinally wrapped copper strip. The outer conductor 3 is further provided with at least one arcuate slot 6 having a length of 12 mm, a width of 1.6 mm and an arc of 4. When there are a plurality of slots 6, the slots 6 have a pitch of 260 mm. The outer conductor 3 has a thickness of 0.2 mm.

The sheath 4 is wrapped around the outer conductor 3, and the sheath 4 is formed of a polyperfluoroethylene propylene wrap.

Embodiment 3

Referring to FIG. 3, a leaky coaxial cable according to an embodiment of the present invention includes an inner conductor 1, an insulating layer 2, an outer conductor 3, and a sheath 4 in this order from the inside to the outside.

The inner conductor 1 is composed of a 3 mm silver plated copper wire.

The insulating layer 2 is wrapped on the outside of the inner conductor 1. The insulating layer 2 is composed of a microporous polytetrafluoroethylene package, and the outer diameter of the insulating layer 2 is 3.5 mm.

The outer conductor 3 is wrapped on the outside of the insulating layer 2, and the outer conductor 3 is composed of slit-woven galvanized copper wire, and the slot 8 is formed according to a certain weaving density, and the knitting density is 60%.

The sheath 4 is wrapped around the outer conductor 3, and the sheath 4 is formed by extrusion of polyperfluoroethylene propylene.

Embodiment 4

The polyperfluoroethylene propylene and the 90# solvent oil are thoroughly stirred, and then matured at 30 ° C in a ripening cabinet, and the aged mixture is pressed into an acrylic tube through a binder control box, and the mixture in the acrylic tube is mixed. Pour into the cylinder of the pusher, place the inner conductor, and then coextrude the mixture with the inner conductor to form an inner conductor with an insulating layer. The brake pressure is 6 MPa, and the push volatilization temperature is 190 °C. The 90# solvent oil percentage was 16%.

Then, a plurality of galvanized copper wires are wound on the insulating layer according to a desired weaving density, and a gap between each galvanized copper wire has a weaving density of 60% to form an outer conductor;

A jacket is formed by extrusion of polyperfluoroethylene propylene on the outer conductor.

Embodiment 5

The ethylene-tetrafluoroethylene copolymer and the 90# solvent oil are thoroughly stirred, and then matured at 40 ° C in a ripening cabinet, and the aged mixture is pressed into an acrylic tube through a press control box, and the acrylic tube is placed in the acrylic tube. The mixture was poured into the cylinder of the pusher, placed in the inner conductor, and then the mixture was coextruded with the inner conductor to form an inner conductor with an insulating layer, the brake pressure was 10 MPa, and the pushing volatilization temperature was 220 °C. The 90# solvent oil ratio was 22%.

Then, a plurality of galvanized copper wires are wound on the insulating layer according to a desired weaving density, and a gap between each galvanized copper wire has a weaving density of 75% to form an outer conductor;

A jacket is formed by extrusion of polyperfluoroethylene propylene on the outer conductor.

Embodiment 6

The polyvinylidene fluoride is wrapped around the two layers to form an insulating layer on the inner conductor.

Then, the slotted copper strip is micro-rolled and then longitudinally overlapped on the insulating layer to form an outer conductor, and a plurality of arc-shaped slots are provided on the outer conductor according to the required lateral radiation performance requirements.

A sheath of polyperfluoroethylene propylene is wrapped around the outer conductor, and a marking line is placed on the sheath.

The above embodiments are only used to illustrate the technical solutions of the present invention, and the present invention is not limited thereto. The present invention will be described in detail with reference to the preferred embodiments, and those skilled in the art should understand that the technical solutions of the present invention may be modified or substituted. Without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A leaky coaxial cable, which is an inner conductor, an insulating layer, an outer conductor and a sheath from the inside to the outside, and the inner conductor is composed of a conductive pipe, characterized in that the insulating layer is wrapped outside the inner conductor. The insulating layer is composed of a high dielectric constant high temperature material, the outer conductor is wrapped outside the insulating layer, the outer conductor is composed of a conductive strip, and the sheath is wrapped outside the outer conductor, and the sheath is protected by oxidation Made of high temperature resistant material.
2. The leaky coaxial cable according to claim 1, wherein said high dielectric constant high temperature resistant material is polytetrafluoroethylene, polyperfluoroethylene propylene, ethylene-tetrafluoroethylene copolymer and polyvinylidene fluoride. At least one of them.
3. The leaky coaxial cable according to claim 1, wherein said insulating layer has an outer diameter of 0.1 to 7 mm.
4. The leaky coaxial cable according to claim 1, wherein said inner conductor is made of a conductive tube, said conductive tube being a tubular or linear conductive material, and said tubular conductive material comprises a hollow tube or a solid tube. The conductive pipe comprises at least one of a silver plated copper wire, a silver plated copper clad steel wire, a solid copper wire, and a copper pipe.
5. The leaky coaxial cable according to claim 1, wherein said outer conductor is composed of a conductive strip material, said conductive strip material being a strip-shaped or filament-like braided conductive material, said conductive strip material comprising galvanized At least one of a copper wire, a galvanized copper clad steel wire, a silver plated copper wire, a silver plated copper clad steel wire, and a copper tape.
6. The leaky coaxial cable of claim 1 wherein said oxidation resistant refractory material is polyperfluoroethylene propylene.
7. A method of manufacturing a leaky coaxial cable according to claim 1, comprising the steps of:

   (1) pushing, extruding or wrapping a high dielectric constant high temperature resistant material on an inner conductor to form an insulating layer, the high dielectric constant high temperature resistant material being polytetrafluoroethylene, polyperfluoroethylene propylene At least one of an ethylene-tetrafluoroethylene copolymer and polyvinylidene fluoride;

   (2) winding the conductive strip on the insulating layer by means of slit-woven galvanized copper wire, galvanized copper-clad steel wire, silver-plated copper wire or silver-plated copper-clad steel wire, or longitudinally wrapping the conductive strip or Laying the slotted copper strip over the insulating layer to form an outer conductor;

   (3) Forming a sheath on the outer conductor by wrapping or extruding the oxidation resistant high temperature resistant material.
8. The method for preparing a leaky coaxial cable according to claim 7, wherein said pushing in said step (1) comprises sufficiently stirring a high dielectric constant high temperature resistant material and an auxiliary oil, and then placing the same The ripening cabinet is matured, and the matured mixed slurry is pressed into the acrylic tube through the press control box, the mixture in the acrylic tube is poured into the pusher cylinder, the inner conductor is placed, and then the mixture and the inner conductor are mixed. Co-extrusion forms an inner conductor with an insulating layer.
9. The method for preparing a leaky coaxial cable according to claim 7, wherein the gap-woven galvanized copper wire, the galvanized copper-clad steel wire, the silver-plated copper wire or the silver-plated copper in the step (2) The method of wrapping steel wire is to wind a plurality of galvanized copper wires, galvanized copper clad steel wires, silver-plated copper wires or silver-plated copper clad steel wires on the insulating layer according to the required weaving density, each galvanized copper wire. The gap between the galvanized copper clad steel wire, the silver plated copper wire or the silver plated copper clad steel wire is controlled by the weaving density to control the lateral radiation performance of the final product.
10.  The method for preparing a leaky coaxial cable according to claim 7, wherein the step of wrapping the wrapped copper strip in the step (2) is to vertically or wrap the slotted copper strip. The package is attached to the insulating layer, and different grooved structures are provided according to the required lateral radiation performance requirements.

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