CN103022610A

CN103022610A - Coupled leakage cable

Info

Publication number: CN103022610A
Application number: CN2012105697234A
Authority: CN
Inventors: 张祥金; 陈长军; 黄军武
Original assignee: ZHEJIANG DETONG TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG DETONG TECHNOLOGY Co Ltd
Priority date: 2012-12-25
Filing date: 2012-12-25
Publication date: 2013-04-03

Abstract

The invention relates to the cable technology, in particular to a coupled leakage cable. The technical scheme includes that the coupled leakage cable comprises an inner conductor, an insulating layer coated outside the inner conductor, an outer conductor coated outside the insulating layer and a sheath coated outside the outer conductor, the outer conductor is provided with multiple smooth and parallel-distributed annular protrusions which enable the outer conductor to be winkled, each annular protrusion is provided with a smooth hole, and the insulating layer comprises an inner thin layer coated on the inner conductor, a foaming layer coated on the inner thin layer and an outer thin layer coated on the foaming layer. The coupled leakage cable has good electric performance.

Description

A kind of coupled mode leaky cable

Technical field

The present invention relates to cable technology, particularly a kind of coupled mode leaky cable.

Background technology

The coupled mode leaky cable is the not exclusively cable of sealing of outer conductor; In the process that radiofrequency signal is transmitted in leakage coaxial cable, a part is coupled to space outerpace by the outer conductor hole, and opposite external radio-frequency signal also can be coupled to cable inside by the outer conductor hole; Thereby leaky cable has the transmitting effect of dual-use function, radiofrequency signal and the reception of reception antenna is done; Be mainly used in the weak busy district of communication system, such as tunnel, subway; Yet its insulation layer structure of leaky cable of the prior art is comparatively single, so that the electric property of leaky cable is relatively poor.

Summary of the invention

The purpose of this invention is to provide a kind of coupled mode leaky cable, have good electric property.

Above-mentioned technical purpose of the present invention is achieved by the following technical programs: a kind of coupled mode leaky cable, comprise inner wire, be coated on the outer insulating barrier of described inner wire, be coated on the outer outer conductor of described insulating barrier, be coated on the outer sheath of described outer conductor, having a plurality of annular projections smooth and parallel distribution on the described outer conductor makes described outer conductor be accordion, each described annular projection has smooth hole, and described insulating barrier comprises the interior thin layer that is coated on described inner wire, be coated on the foaming layer of described interior thin layer, be coated on the outer outer thin layer of described foaming layer.

As of the present invention preferred, the foam degrees of described foaming layer 〉=85%.

As of the present invention preferred, the distance between the adjacent described annular projection is 5-10mm.

As of the present invention preferred, the crest external diameter of described outer conductor is 22-25mm, and the trough external diameter is 20-22mm.

As of the present invention preferred, the diameter of described inner wire is 8-12mm.

As of the present invention preferred, the external diameter of described insulating barrier is 14-20mm.

As of the present invention preferred, described hole is ellipticity.

As of the present invention preferred, the hole on each described annular projection is 4-6, and evenly distributes.

In sum, the present invention has following beneficial effect: the insulation layer structure of uniqueness of the present invention makes the present invention have outstanding electric property, has simultaneously the advantages such as stable mechanical performance, intensity height and humidity resistance are good; Simultaneously adopt the oxygen-free copper conductor at internal and external conductor, conductance 〉=100%, oxygen content＜10ppm, with and reduce the loss factor of conductor; Adopt physical blowing equipment at dielectric, adopt CO ₂Foaming reaches more than 85% the foam degrees of dielectric, has effectively reduced dielectric constant, thereby has reduced dielectric loss coefficient, has improved transmission rate; Simultaneously, because the present invention also has the advantages such as coupling loss is little.

Description of drawings

Fig. 1 is embodiment 1 structural representation;

Fig. 2 is insulation layer structure schematic diagram among the embodiment 1.

Among the figure, 1, inner wire, 2, insulating barrier, 3, outer conductor, 4, sheath, 31, annular projection, 32, the hole, 21, interior thin layer, 22, foaming layer, 23, outer thin layer.

Embodiment

Below in conjunction with accompanying drawing the present invention is described in further detail.

This specific embodiment only is explanation of the invention; it is not limitation of the present invention; those skilled in the art can make the modification that does not have creative contribution to present embodiment as required after reading this specification, but as long as all are subject to the protection of Patent Law in claim scope of the present invention.

Embodiment 1: shown in Fig. 1-2, a kind of coupled mode leaky cable, comprise inner wire 1, be coated on the insulating barrier 2 outside the described inner wire 1, be coated on the outer conductor 3 outside the described insulating barrier 2, be coated on the sheath 4 outside the described outer conductor 3, having a plurality of annular projections 31 smooth and parallel distribution on the described outer conductor 3 makes described outer conductor 3 be accordion, each described annular projection 31 has smooth hole 32, and described insulating barrier 2 comprises the interior thin layer 21 that is coated on described inner wire 1, be coated on the foaming layer 22 of described interior thin layer 21, be coated on the outer thin layer 23 outside the described foaming layer 22; The foam degrees of foaming layer 22 〉=85%; Distance between the adjacent annular projection 31 is 7mm; The crest external diameter of outer conductor 3 is 24mm, and the trough external diameter is 21mm; The diameter of inner wire 1 is 10mm; The external diameter of insulating barrier 2 is 18mm; Hole 32 is ellipticity; Hole 32 on each annular projection 31 is 4, and evenly distributes.

The preparation method is as follows: may further comprise the steps successively:

(1) preparation of inner wire;

(2) extruded insulation body, first inner wire is passed into interior thin layer extruder, thin layer in outside inner wire, forming, be divided into three sections temperature controls from charging aperture to the discharging opening of interior thin layer extruder, being followed successively by first paragraph 150 degree and temperature retention time is 3min, second segment 170 degree and temperature retention time are 4min, and the 3rd section is that 185 degree and temperature retention time are 5min; The inner wire that will be extruded with again interior thin layer passes into the foaming insulation layer extruder and forms insulating barrier, with the 69wt% high density polyethylene (HDPE), the 30wt% low density polyethylene (LDPE), 1wt% modification azo diformazan phthalein amine nucleator is mixed to be incorporated in heating and melting in the foaming insulation layer extruder, subsequently heating and gasifying purity is reached 99.9% CO ₂Gas injects melting insulator, abundant mixing mixing by the syringe metering with 390Mpa pressure; Control gas injection port place temperature 200 degree, insulation melts temperature 150 degree, extrusion mould-outlet temperature 130 degree, and controller neck to the die orifice temperature difference is ± 2 degree, make the temperature that extrudes the inner wire behind the interior thin layer be down to 55 degree and enter die orifice, under the pressurized condition, make molten mixture together by extrusion die, thereby form foaming layer, the foam degrees of foaming layer 〉=85%; Thin layer outside forming outside foaming layer by outer thin layer extruder again, outer thin layer extruder has three sections temperature controls by charging aperture to extruding end, being followed successively by first paragraph 155 degree and temperature retention time is 4min, and second segment 165 degree and temperature retention time are 3min, and the 3rd section is that 190 degree and temperature retention time are 5min;

(3) outer conductor preparation, the thin layer outer cladding adopts the copper pipe that oxygen-free copper is made outside, and again through the stable head of embossing that rotates and embossing cutter after roughing preforming and finish rolling forming process, form annular wrinkle copper pipe outer conductor to the copper tube rolling extrusion molding at a high speed;

(4) perforate evenly arranges hole on the annular protrusion of annular wrinkle copper pipe outer conductor; The pitch of described annular wrinkle copper pipe outer conductor is 7mm; The crest external diameter of described annular wrinkle copper pipe outer conductor is 24mm, and the trough external diameter is 21mm; Hole is ellipticity, and is provided with 4 on each annular protrusion;

(5) extrude sheath, utilize plastic extruder, protective cover material is promoted melting through preheating, screw rod Stirring, will pass into the plastics plastic extruding machine through the semi-finished product of step (3) again, the continuously and smoothly extrudes through the extrusion die shaping, forms sheath outward thereby make protective cover material be coated on outer conductor; The plastics plastic extruding machine has seven sections temperature controls by charging aperture to extruding end, being followed successively by first paragraph 175 degree and temperature retention time is 2min, second segment 195 degree and temperature retention time are 3min, the 3rd section 205 the degree and temperature retention time be 3min, the 4th section 195 the degree and temperature retention time be 4min, the 5th section 185 the degree and temperature retention time be 3.5min, the 6th section 175 the degree and temperature retention time be 4min, the 7th section 165 the degree and temperature retention time be 3min.

The partial parameters of 7/8 coupled mode leaky cable of present embodiment preparation is as follows:

1, return loss: 1MHZ-3000MHZ 21dB, 300MHZ-500MHZ 26dB, 800MHZ-1000MHZ 26dB, 1700MHZ-1900MHZ 26dB, 1900MHZ-3000MHZ 21dB;

2, decay: 75MHZ-1.18 dB/100m, 150MHZ-1.68dB/100m, 450MHZ-2.8 dB/100m, 800MHZ-4.0dB/100m, 900MHZ-4.3dB/100m, 1800MHZ-6.5 dB/100m, 2200MHZ-7.4 dB/100m, 2400MHZ-8.2 dB/100m;

3, coupling loss (50% ± 10dB) 75MHZ-62/72dB, 150MHZ-65/75dB, 450MHZ-71/81dB, 800MHZ-75/85 dB, 900MHZ-71/87 dB, 1800MHZ-80/89 dB, 2200MHZ-80/88 dB, 2400MHZ-80/89dB;

4, impedance: 50 ± 1 Ω;

5, transmission speed ratio: 88%;

6, inner wire D.C. resistance: 1.0 Ω/km;

7, outer conductor D.C. resistance: 1.2 Ω/km;

8, dielectric strength: 10kv;

9, insulation resistance: 10000M Ω/km.

Embodiment 2: be that with the difference of embodiment 1 distance between the adjacent annular projection 31 is 5mm; The crest external diameter of outer conductor 3 is 22mm, and the trough external diameter is 20mm; The diameter of inner wire 1 is 8mm; The external diameter of insulating barrier 2 is 14mm; Hole 32 is ellipticity; Hole 32 on each annular projection 31 is 5, and evenly distributes.

The preparation method is similar to Example 1.

Embodiment 3: be that with the difference of embodiment 1 distance between the adjacent annular projection 31 is 10mm; The crest external diameter of outer conductor 3 is 25mm, and the trough external diameter is 22mm; The diameter of inner wire 1 is 12mm; The external diameter of insulating barrier 2 is 20mm; Hole 32 is ellipticity; Hole 32 on each annular projection 31 is 6, and evenly distributes.

The preparation method is similar to Example 1.

Claims

1. coupled mode leaky cable, comprise inner wire (1), be coated on the outer insulating barrier (2) of described inner wire (1), be coated on the outer outer conductor (3) of described insulating barrier (2), be coated on the outer sheath (4) of described outer conductor (3), having a plurality of annular projections (31) smooth and parallel distribution on the described outer conductor (3) makes described outer conductor (3) be accordion, each described annular projection (31) has smooth hole (32), it is characterized in that described insulating barrier (2) comprises the interior thin layer (21) that is coated on described inner wire (1), be coated on the foaming layer (22) of described interior thin layer (21), be coated on the outer outer thin layer (23) of described foaming layer (22).

2. a kind of coupled mode leaky cable according to claim 1 is characterized in that, the foam degrees of described foaming layer (22) 〉=85%.

3. a kind of coupled mode leaky cable according to claim 2 is characterized in that, the distance between the adjacent described annular projection (31) is 5-10mm.

4. a kind of coupled mode leaky cable according to claim 3 is characterized in that, the crest external diameter of described outer conductor (3) is 22-25mm, and the trough external diameter is 20-22mm.

5. a kind of coupled mode leaky cable according to claim 4 is characterized in that, the diameter of described inner wire (1) is 8-12mm.

6. a kind of coupled mode leaky cable according to claim 5 is characterized in that, the external diameter of described insulating barrier (2) is 14-20mm.

7. a kind of coupled mode leaky cable according to claim 1 is characterized in that, described hole (32) are ellipticity.

8. a kind of coupled mode leaky cable according to claim 7 is characterized in that, the hole (32) on each described annular projection (31) is 4-6, and evenly distributes.