CN209993356U - Fireproof railway digital communication cable - Google Patents

Abstract

The utility model belongs to the technical field of the cable technique and specifically relates to a fire prevention type railway digital communication cable, including shielding layer, the hank body and signal line pair, the hank body includes insulating core and water conservancy diversion line, the water conservancy diversion line transposition is on insulating core, insulating core includes inner conductor and inner insulating layer, the inner insulating layer parcel is in the inner conductor outside, the shielding layer cladding is on the surface at the transposition body, a shielding layer outside parcel outer insulating layer, the signal line pair specifically is two outer insulating layer glues together, it has the tensile layer to alternate between the signal line pair, the signal line wraps up there is inside flame retardant coating to the outside, the inside flame retardant coating outside is impressed and is separated the oxygen layer, it has outside flame retardant coating to separate the surface suppression of oxygen layer. The utility model discloses it is little to transmit attenuation value in high low temperature environment, and transmission rate is high, and transmission performance is reliable and stable, practices thrift characteristics such as cost.

Description

Fireproof railway digital communication cable

Technical Field

The utility model relates to the technical field of cables, especially, relate to a fire prevention type railway digital signal cable.

Background

With the rapid development of China railways in recent years, the business mileage of railways in China reaches 12 kilometers, the railways are in the top of the world, the whole economy of China faces down-stream pressure, and the increase of railway investment strength has a great positive effect on pulling the national economy to increase.

By increasing the railway construction strength, on one hand, the development of industries such as steel, cement, building materials and the like which are closely related to the railway construction can be directly driven, and employment is promoted; on the other hand, the continuous construction and development of railways, particularly the development of high-speed rails, also have positive significance on the economic development and the investment and investment of various regions along the route. It is known that the development of the Chinese railways is extremely uneven, the networks of the Chinese and western railways are very sparse, and the development of the western economy is restricted by the backward traffic, which is one of the important factors that cause the development gap with the east and the west areas to be continuously widened. Railway construction parts continuously pull and stimulate the consumption potential of the middle and western regions with lower current overall level, and the circulation of production distribution and exchange links of the middle and western regions is enhanced, so that the employment and income of local residents are improved to some extent, the consumption is continuously increased, and the production of consumer goods is stimulated. The high-speed railway can be completely constructed in the future, the market potential of high-speed railway equipment is high, and particularly, the consumption of data cables connected for transmitting signals is larger.

With the continuous update of high-speed rail equipment technology, the requirements on signal cables are higher and higher, for example, when the high-speed rail equipment is operated in northeast and far east extremely cold regions in Russia, the lowest temperature in winter reaches-55 ℃, the conventional cables are easy to crack the sheath, the low temperature damages the inner cable cores, and the signal transmission performance is finally influenced. When a conventional low-dielectric physical foaming polyethylene insulated data cable meets high-temperature parts, the cable can generate a larger signal transmission attenuation phenomenon. Meanwhile, when the speed of the high-speed train reaches 350km/h, if the internal data cable is short-circuited, the conventional physical foamed polyethylene insulated data cable can generate a burning phenomenon, and the driving safety of the high-speed train is seriously damaged. The utility model discloses a product is innovated above material and production technology, structurally optimizes, the utility model discloses the cable product possesses good fire behavior.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the shortcoming that has digital signal cable transmission loss among the prior art big, manufacturing cost is high, and fire behavior is poor, and the fire prevention type railway digital communication cable who provides.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the design is a fireproof railway digital communication cable, which comprises a shielding layer, a stranded body and a signal line pair, wherein the stranded body comprises an insulating wire core and a diversion line, the diversion line is stranded on the insulating wire core, the insulating wire core comprises an inner conductor and an inner insulating layer, the inner insulating layer is wrapped on the outer side of the inner conductor, the shielding layer is wrapped on the surface of a stranded body, the outer insulating layer is wrapped on the outer side of the shielding layer, the signal line pair is specifically two outer insulating layer adhesives, a tensile layer is inserted between the signal line pair, the outer side of the signal line pair is wrapped with an inner fireproof layer, an oxygen separation layer is pressed on the outer side of the inner fireproof layer, and an outer fireproof layer is pressed on the surface of the oxygen separation layer.

Preferably, the diversion line is a tinned copper wire formed by twisting a plurality of strands.

Preferably, the outer insulating layer is spirally wound on the surface of the shielding layer.

Preferably, the outer side of the oxygen isolation layer is wrapped with a ceramic polyolefin sheath.

Preferably, the inner conductor is a tinned copper wire.

The utility model provides a pair of fire prevention type railway digital signal cable, beneficial effect lies in: the fireproof railway digital signal cable uses the physical foaming fluorinated ethylene propylene insulating layer on a wire core structure, the average dielectric constant of the wire core is reduced by the structure, the requirement of low attenuation of signal transmission is met, the transmission rate of the wire core is improved, the outer diameter of the wire core is reduced under the condition of reaching the same transmission performance, and a large amount of insulating materials are saved, so that the production cost is reduced, the traditional high-speed train data cable adopts the physical foaming polyethylene insulating layer, the foaming degree is about 50 percent, the transmission rate is 81 percent, and the material is saved by 66 percent, the utility model discloses a cable uses the fluorinated ethylene propylene physical foaming insulating layer, the foaming rate is more than 70 percent, the transmission rate is about 88 percent, the material is saved by 81 percent, the maximum attenuation value is less than 20dB/km when the frequency is 3MHz, the working capacitance of 2MHz is less than or equal to 4.6pF/m, the dielectric strength is, no breakdown occurred for 5 min. Insulation resistance is more than or equal to 5000M ohm.km, simultaneously, the surface of the insulation layer is extruded and coated with a layer of fluorinated ethylene propylene outer skin layer, so that the line pair structure is more stable, the characteristic impedance meets 120 +/-10 ohm at 3MHz, the utility model discloses a product sheath uses ceramic polyolefin material, which has the characteristics of good mechanical property, fire resistance, environmental protection weatherability and corrosion resistance, the electrical property and the transmission property of the product are not changed when the product is used in a temperature range of-90 ℃ to 200 ℃ for a long time, the traditional railway digital signal cable fireproof cable uses structures such as mica tape and the like wrapping objects and metal armoring layers and the like on the design, the process is complex in the production process, the utility model discloses a product uses the novel main fireproof oxygen insulation layer material, is completed at one time through a double-layer co-extrusion type thermal extrusion molding method, and completes the original three processes by one process, reduced cable manufacturing cost, the utility model discloses the cable oversheath uses ceramic polyolefin material, and this material possesses fine fire prevention efficiency, and its combustion behavior satisfies A level (incombustible cable) regulation requirement in GB31247-2014 (cable and optical cable combustion behavior are hierarchical) standard. The combustion heat value test is carried out according to a method specified in GB/T14402-2007 determination of combustion performance combustion heat values of building materials and products, the total heat value PCS is less than or equal to 2.0MJ/kg, the test and confirmation are carried out according to GB/T31248-2014 test methods of flame spread, heat release and smoke generation characteristics of cables or optical cables under the fire condition, the flame spread height FS is less than or equal to 1.5 after the cables or optical cables are combusted for 20 minutes, the peak value of the smoke generation density is less than or equal to 0.25m2/s, no dripping is generated within 20 minutes of combustion, the smoke toxicity level reaches AQ2 level specified in GB/T20285-2206 (material smoke generation toxicity grading) standard, the conductivity of the corrosivity test is 1.5 mu s/mm (standard requirement is less than or equal to 2.5 mu s/mm), and the PH value is 5.8 (standard requirement is more than or equal to 4.3), and no secondary hazard is generated.

Drawings

Fig. 1 is the utility model provides a fire prevention type railway digital signal cable's schematic structure diagram.

In the figure: the inner conductor 1, the inner insulating layer 2, the shielding layer 3, the outer insulating layer 4, the flow guide line 5, the inner flame retardant coating 6, the oxygen isolation layer 7, the outer flame retardant coating 8 and the tensile layer 9.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

Referring to fig. 1, a fireproof railway digital signal cable comprises a shielding layer 3, a stranded body and a signal line pair, wherein the stranded body comprises an insulating wire core and a guide wire 5, the guide wire 5 is stranded on the insulating wire core, the insulating wire core comprises an inner conductor 1 and an inner insulating layer 2, the inner insulating layer 2 wraps the outer side of the inner conductor 1, the shielding layer 3 wraps the surface of the stranded body, the outer insulating layer 4 wraps the outer side of the shielding layer 3, the signal line pair is specifically formed by bonding two outer insulating layers 4 together through glue, a tensile layer 9 is inserted between the signal line pair, the outer side of the signal line pair is wrapped with an inner fireproof layer 6, an oxygen isolation layer 7 is pressed on the outer side of the inner fireproof layer 6, and an outer fireproof layer 8 is pressed on. Inner conductor 1 adopts stranded tinned copper wire to twist and forms, inner insulating layer 2 uses and gathers perfluor ethylene propylene crowded package in inner conductor 1 surface, through using "skin bubble skin" physics foaming technique, its foaming degree reaches more than 70%, this insulating material dielectric constant is little and stable, possess high low temperature resistance requirement, the insulation core and the water conservancy diversion line 5 of different colours twist according to certain transposition pitch, shielding layer 3 uses two-sided electrically conductive aluminium foil in order to wrap 360 degrees cladding in insulation core and water conservancy diversion line strand surface of form of package, outer insulating layer 4 uses 360 degrees claddings in shielding 3 surface formation outer insulating layer 4 in polyester area, signal line pair is accomplished to 4 outer insulating layer structures, be equipped with inside flame retardant coating 6 between signal line pair and outside flame retardant coating 8, separate oxygen layer 7, tensile layer 9. The inner fireproof layer 6 is wrapped on the signal line pair table in a ceramic polyolefin material in an extruding mode to form a third fireproof body layer, and the inner fireproof layer structure is completed.

The oxygen isolating layer 7 is made of a new material, has high flame-retardant effect when being burnt at high temperature, and has the following formula: 45-78 parts of inorganic adhesive, 28-60 parts of flame retardant, 18-63 parts of inorganic filler, 5-13% of mica powder, and silicon dioxide powder: 16.8% -17.8% of calcium carbonate and 4% -5% of calcium carbonate, wherein the materials form a second layer of refractory body to complete the structure of the oxygen-isolating layer 7, the outer refractory layer 8 uses a ceramic polyolefin light sheath material to form a first layer of refractory body to complete the structure of the outer refractory layer, the material rapidly releases water vapor on the surface when burning in open fire, meanwhile, the material is solidified to form an armor body, flame-retardant flame is further spread to protect the internal structure of the cable, the oxygen-isolating layer 7 and the outer refractory layer 8 are completed by a double-layer co-extrusion method, namely, the oxygen-isolating layer 7 material and the outer refractory layer 8 material are synchronously extruded and wrapped firstly, the method reduces the production cost, and the tensile layer 9 uses a heating application type filling compound and has high tensile strength.

The utility model discloses a tinned copper conductor, physics foaming are gathered perfluoro ethylene propylene and are insulated as the signal transmission dielectric medium body, and its dielectric constant is 1.6, and high frequency signal transmission decay reduces, is gathering perfluoro ethylene propylene foaming layer surface crowded package one deck and gathering the perfluoro ethylene propylene protective layer simultaneously, prevents that moisture invasion foaming edge insulating layer, ensures that the signal transmission performance is more reliable. In addition, each line pair sub-shielding layer 3 adopts an independent grounding structure, namely, each signal line pair is wrapped with aluminum foil after being added with a ground wire, then is wrapped with a polyester tape for insulation, in order to comprehensively meet the fire resistance of the cable, a ceramic polyolefin fire-resistant layer is extruded on the surface of a cable core stranded body to serve as a third layer body to resist fire, and the signal cable is provided with a second layer fire-resistant body structure and is embodied through an oxygen isolation layer 7.

The surface of the inner conductor 1 is extruded with a layer of 0.05mm fluorinated ethylene propylene inner skin layer, the surface of the inner skin layer is extruded with a layer of fluorinated ethylene propylene physical foaming layer to form an insulating layer, and the surface of the foaming layer is extruded with a layer of 0.1mm fluorinated ethylene propylene outer skin layer.

The structure is completed through a three-layer co-extrusion nitrogen-filling physical foaming production line. The shielding layer 3 is formed by twisting two insulated wire cores, a grounding wire, an aluminum foil and a protective layer according to a certain pitch, wherein the aluminum foil conductive surface is contacted with the internal grounding wire. The diversion line is formed by twisting a plurality of strands of tinned copper wires, and the form is favorable for preventing the signal wire pairs from interfering with each other. The fireproof layer is made of ceramic polyolefin material, the oxygen-isolating layer 7 is made of new material, the formula of the fireproof layer is original, the fireproof layer is extruded on the surface of the oxygen-isolating layer 7 and is completed by a double-layer co-extrusion method, the ceramic polyolefin is used as the material, the material does not absorb water and moisture, the dielectric strength is more than or equal to 22KV/mm at normal temperature, the volume resistivity is more than or equal to 2 multiplied by 1014 ohm cm, uniform micropores can be generated on the section of the hard armor body after ablation, the dielectric strength of the hard armor body after ceramic is more than 24KV/mm, the volume resistivity is more than 2 multiplied by 1015 ohm cm, the highest oxygen index can reach more than 45, the ceramic armor body is flame-retardant, low-smoke, halogen-free and harmless, does not delay combustion, does not drip or fall, can also form a very hard ceramic armor shell after ablation, the cable has a protection effect on the internal structure of the cable, and the tensile layer 9 is made of heating application type filling compound materials and has high tensile strength.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims (5)

1. The utility model provides a fire prevention type railway digital communication cable, includes shielding layer (3), the twister and signal line pair, its characterized in that: the stranding body includes insulation core and water conservancy diversion line (5), water conservancy diversion line (5) transposition is on insulation core, insulation core includes inner conductor (1) and inner insulating layer (2), inner insulating layer (2) parcel is in the inner conductor (1) outside, shielding layer (3) cladding is on the strand surface, shielding layer (3) outside parcel one layer of outer insulating layer (4), the signal line is specifically two outer insulating layer (4) gluing together, it has tensile layer (9) to alternate between the signal line pair, the signal line has inside flame retardant coating (6) to the outside parcel, inside flame retardant coating (6) outside suppression has oxygen layer (7) that separates, it has outside flame retardant coating (8) to separate oxygen layer (7) surface suppression.

2. The fire-proof railway digital communication cable according to claim 1, wherein the diversion line (5) is a stranded tinned copper wire.

3. A fire-resistant railway digital communication cable according to claim 1, wherein the outer insulating layer (4) is spirally wound on the surface of the shielding layer (3).

4. The fire-proof railway digital communication cable according to claim 1, wherein the oxygen barrier layer (7) is coated with a ceramic polyolefin sheath.

5. A fire-resistant railway digital communication cable according to claim 1, characterized in that said inner conductor (1) uses tinned copper wire.