阅读说明：本技术 一种深海潜航设备用纵向水密复合缆及其制备工艺 (Longitudinal watertight composite cable for deep sea underwater vehicle and preparation process thereof ) 是由 袁保平 鲁海燕 洪永飞 黄年华 于 2020-05-22 设计创作，主要内容包括：本发明涉及深海潜航用电缆领域,具体涉及一种深海潜航设备用纵向水密复合缆及其制备工艺,该电缆包括电力控制单元、网络传输单元,在电力控制单元和网络传输单元的外侧依次设置有第二阻水绕包层、内护套、铠装、外护套。本发明复合缆满足纵向水密功能要求,耐纵向水压6.75Mpa,实现了纵向水密、网络信号传输、电力控制信号传输等功能的综合化,利用结构的复合化设计,以解决其相互间的电磁兼容问题。(The invention relates to the field of cables for deep sea underwater navigation, in particular to a longitudinal watertight composite cable for deep sea underwater navigation equipment and a preparation process thereof. The composite cable meets the requirements of longitudinal watertight function, resists longitudinal water pressure of 6.75Mpa, realizes the integration of longitudinal watertight, network signal transmission, electric power control signal transmission and other functions, and solves the problem of mutual electromagnetic compatibility by utilizing the composite design of the structure.)

1. A longitudinal watertight composite cable for deep sea underwater vehicle is characterized by comprising:

the power control unit (1), the power control unit (1) comprises a plurality of composite insulating wire cores (7), each composite insulating wire core (7) comprises an injection conductor (1.1), a composite insulating layer (1.2) is arranged outside each injection conductor (1.1), a first water-blocking wrapping layer (1.4) is arranged on the outer layer of each twisted composite insulating wire core (7), each composite insulating layer (1.2) comprises a polyethylene inner insulating layer and a polyolefin outer insulating layer, and the thickness ratio of the polyethylene inner insulating layer to the polyolefin outer insulating layer is 1: 1-2;

the network transmission unit (2), the network transmission unit (2) includes a plurality of network transmission cable cores (8), the network transmission cable cores (8) include network transmission conductors (2.1), the outside of the network transmission conductors (2.1) is provided with an insulating layer (2.2), and the outside of the twisted network transmission cable cores (8) is provided with a shielding layer;

the power control unit (1) and the network transmission unit (2) are twisted, and after the twisting, the second water-blocking wrapping layer (3), the inner sheath (4), the armor (5) and the outer sheath (6) are sequentially arranged.

2. The composite cable according to claim 1, wherein the shielding layer of the network transmission unit (2) comprises an aluminum foil wrapping layer (2.3) and a braided shielding layer (2.4) which are arranged from inside to outside, the wrapping coverage rate of the aluminum foil wrapping layer (2.3) is 40-50%, and the braiding density of the braided shielding layer (2.4) is not lower than 88%.

3. A composite cable according to claim 2, wherein the armour (5) is a composite water-blocking armour comprising woven armour and a water-blocking tape layer provided on both sides of the woven armour.

4. The composite cable according to claim 3, wherein the power control unit (1) comprises 4 to 19 groups of composite insulated wire cores (7) and 2 to 10 groups of network transmission units (2).

5. The composite cable according to claim 4, wherein the plurality of groups of composite insulated wire cores (7) are contained in the power control unit (1), and the plurality of groups of composite insulated wire cores (7) are stranded into the cable while being impregnated with the single-component room temperature vulcanized silicone rubber.

6. The composite cable according to claim 5, wherein the network transmission units (2) are in multiple groups, and the multiple groups of network transmission units (2) are dispersedly twisted around the power control unit (1) while injecting single-component room temperature vulcanized silicone rubber.

7. The composite cable according to claim 1, wherein the composite insulated wire core (7), the inner jacket (4) and the outer jacket (6) are radiation crosslinked, and the thermal elongation of the composite insulated wire core (7) after irradiation is no greater than 30%.

8. The composite cable according to claim 1, further comprising a filler core (1.3), said filler core (1.3) being stranded with the composite insulated wire core (7); and/or twisted with a network transmission conductor (2.1) with an insulating layer (2.2); and/or twisted with the power control unit (1) and the network transmission unit (2).

9. A preparation process of the longitudinal watertight composite cable for the deep sea diving equipment as claimed in any one of claims 1 to 8, characterized by comprising:

1) preparation of power control unit (1):

a glue injection conductor (1.1) is formed by stranding a plurality of strands of copper cores containing plating layers and then filling quick-drying neoprene in a stranding die to fill gaps;

b, double-layer co-extrusion is carried out on the outer layer of the glue injection conductor (1.1) to wrap a composite insulating layer (1.2) consisting of a polyethylene inner insulating layer and a polyolefin outer insulating layer, the thickness ratio of the polyethylene inner insulating layer to the polyolefin outer insulating layer of the composite insulating layer (1.2) is 1: 1-2, the glue injection conductor (1.1) and the composite insulating layer (1.2) form a composite insulating wire core (7), the composite insulating wire core (7) is subjected to irradiation crosslinking, and the thermal elongation value of the composite insulating layer after irradiation is less than or equal to 30%;

c, twisting a plurality of composite insulating wire cores (7), adding single-component room-temperature vulcanized silica gel while twisting during cabling, and wrapping a first water-blocking wrapping layer (1.4) in a winding manner;

2) preparing a network transmission unit (2):

a, extruding an insulating layer (2.2) on the outer layer of a network transmission conductor (2.1) to form a network transmission wire core (8);

b, stranding a plurality of groups of network transmission wire cores (8) obtained in the step a into a cable;

c, arranging a shielding layer outside the cable obtained in the step b;

3) the plurality of network transmission units (2) and the plurality of power control units (1) are cabled, during cabling, single-component room-temperature vulcanized silica gel is injected while being twisted, then a water-blocking tape is wrapped to form a second water-blocking wrapping layer (3), and the wrapping covering rate of the second water-blocking wrapping layer (3) is 40% -50%;

4) extruding the inner sheath (4) on the outer layer of the cable obtained in the step 3), and irradiating and crosslinking the extruded inner sheath (4) by using an electron accelerator;

5) an armor (5) is arranged outside the inner sheath (4),

6) an outer sheath (6) is extruded outside the armor (5), and the outer sheath (6) is irradiated and crosslinked by an electron accelerator.

10. The manufacturing process according to claim 9, wherein the step of disposing the shielding layer in step 2) comprises: and c, filling single-component room temperature vulcanized silica gel into the forming die, lapping a single-sided polyester aluminum foil to form an aluminum foil lapping layer (2.3), wherein the aluminum surface faces outwards, the lapping rate of the aluminum foil lapping layer is 40-50%, then weaving a layer of copper wire containing a plating layer to form a braided shielding layer (2.4), and the weaving density is more than or equal to 88%.

Technical Field

The invention relates to the technical field of cables for deep sea underwater navigation, in particular to a longitudinal watertight composite cable for deep sea underwater navigation equipment and a preparation process thereof.

Background

The longitudinal watertight performance of the longitudinal watertight cable means that under extreme conditions, after the longitudinal end face of the underwater cable is damaged or broken, the longitudinal water pressure along the end face can only be transmitted within a certain distance, so that the water pressure cannot penetrate along the cable to endanger the safety of personnel or cause equipment damage; the composite cable with the longitudinal watertight function is a nerve and a blood vessel of underwater equipment and facilities, the longitudinal watertight cable is a substitute of the scientific and technological content in the field of special electric wires and cables due to the structural particularity, the longitudinal watertight composite cable for power supply control of deep sea underwater navigation equipment and high-speed network transmission can be called as a bright bead on the crown of the longitudinal watertight cable, but the research and development of the cable and the optical cable composite cable for deep sea underwater navigation always have difficulty, so that the requirements on longitudinal watertight are met, and the electromagnetic compatibility problem and other requirements are also met.

Disclosure of Invention

In order to solve the problems, the invention develops a longitudinal watertight composite cable for deep sea underwater vehicle and a preparation process thereof. The water-tight structure meets the requirement of longitudinal water-tight function, resists longitudinal water pressure of 6.75Mpa, realizes the integration of longitudinal water-tight function, network signal transmission, power control signal transmission and other functions, and solves the problem of mutual electromagnetic compatibility by utilizing the composite design of the structure.

The specific scheme of the invention is as follows:

a longitudinal watertight composite cable for deep sea underwater vehicle comprises:

the power control unit comprises a plurality of composite insulating wire cores, each composite insulating wire core comprises an injection conductor, a composite insulating layer is arranged outside each injection conductor, a first water-blocking wrapping layer is arranged on the outer layer of each twisted composite insulating wire core, each composite insulating layer comprises a polyethylene inner insulating layer and a polyolefin outer insulating layer, and the thickness ratio of the inner insulating layer to the outer insulating layer is 1: 1-2; the glue used for the glue injection conductor is quick-drying chloroprene rubber glue; the quick-drying chloroprene rubber adhesive is a mixed type, comprises chloroprene rubber, tackifying resin, a quick-volatile solvent, an anti-aging agent, an accelerating agent, a crosslinking agent and the like, has high surface drying speed, can be dried in a preheating pipe at 300 ℃ for 2s, has good adhesion with a metal conductor after surface drying, has no corrosion to metal, and is more suitable for producing watertight conductors;

the network transmission unit comprises a plurality of network transmission wire cores, each network transmission wire core comprises a network transmission conductor, an insulating layer is arranged outside each network transmission conductor, and a shielding layer is arranged on the outer layer of each network transmission wire core after the network transmission wire cores are twisted;

the power control unit and the network transmission unit are twisted, and after the twisting, the water-blocking wrapping layer, the inner sheath, the armor and the outer sheath are sequentially arranged.

Preferably, the shielding layer of the network transmission unit comprises an aluminum foil wrapping layer and a woven shielding layer which are arranged from inside to outside, the wrapping covering rate of the aluminum foil wrapping layer is 40-50%, and the weaving density of the woven shielding layer is not lower than 88%. The aluminum foil is wrapped and shielded and is woven to form a composite shielding layer, and the shielding effect is greatly improved.

Preferably, the armor is a composite water-blocking armor, and the composite water-blocking armor comprises a woven armor and water-blocking wrapping tape layers arranged on two sides of the woven armor. The armor that so sets up has avoided traditional the rubberizing of weaving the armor both sides and has come to block water, from making the even unity of water blocking layer thickness of both sides, on the other hand makes things convenient for the dismouting more.

Preferably, the composite insulation wire cores contained in the power control unit are 4-19 groups, and the network transmission units are 2-10 groups. And selecting different quantities according to the requirements of different composite cables.

Preferably, the composite insulation wire cores contained in the power control unit are multiple groups, and the multiple groups of composite insulation wire cores are stranded into a cable while injecting glue to form single-component room temperature vulcanized silica gel, so that the power control unit is formed. The effect of injecting glue here makes the stranding structure that becomes more stable on the one hand, and on the other hand the injecting glue that fills in can also play the effect that blocks water. The room temperature vulcanized silica gel is in a white emulsion shape, is non-toxic and non-corrosive, mainly comprises silica gel, a filler, a cross-linking agent, an antioxidant and the like, is in contact with air in a natural environment, is subjected to cross-linking curing, is adhered to an insulating surface, is tightly adhered to an outer layer polyolefin material, and has the effect of sealing a gap.

Preferably, the network transmission units are multiple groups, and the multiple groups of network transmission units are dispersedly twisted around the power control unit, and the single-component room-temperature vulcanized silica gel is injected while the twisting is performed. The arrangement mode enables the power transmission performance and the network transmission performance of the composite cable to be better. The effect of injecting glue here makes the stranding structure that becomes more stable on the one hand, and on the other hand the injecting glue that fills in can also play the effect that blocks water.

Preferably, the composite insulated wire core, the inner sheath and the outer sheath are all subjected to irradiation crosslinking, and the thermal elongation value of the composite insulated wire core after irradiation is less than or equal to 30%.

Preferably, the cable also comprises a filling core, and the filling core is stranded with the composite insulating wire core; and/or twisted with a network transmission conductor with an insulating layer; and/or twisted with the power control unit and the network transmission unit. That is, the filling core is twisted with different units according to the needs of the composite cable, so as to achieve the specific shape or other purposes required by the composite cable.

The preparation process of the longitudinal watertight composite cable for the deep sea underwater vehicle comprises the following steps:

1) preparing a power control unit:

the glue injection conductor A is formed by stranding a plurality of strands of copper cores containing coatings and then filling quick-drying neoprene into a stranding die to fill gaps;

b, double-layer co-extrusion coating is carried out on a composite insulating layer consisting of a polyethylene inner insulating layer and a polyolefin outer insulating layer outside the glue injection conductor, the thickness ratio of the polyethylene inner insulating layer to the polyolefin outer insulating layer is 1: 1-2, the glue injection conductor and the composite insulating layer form a composite insulating wire core, the composite insulating wire core is subjected to irradiation crosslinking, and the thermal extension value of the composite insulating layer after irradiation is less than or equal to 30%; the irradiation enables the thermal extension performance and other performances of the composite insulated wire core to be better, and the performance of the final composite cable is enhanced.

C, stranding a plurality of composite insulating wire cores into a cable, injecting single-component room temperature vulcanized silica gel in front of a forming die during cabling, and wrapping a first water-blocking wrapping layer;

2) preparing a network transmission unit:

a, extruding an insulating layer on the outer layer of the network transmission conductor to form a network transmission wire core;

b, stranding a plurality of groups of network transmission wire cores obtained in the step a into a cable;

c, arranging a shielding layer outside the cable obtained in the step b;

3) the plurality of network transmission units and the plurality of power control units form a cable, during cabling, the single-component room temperature vulcanized silica gel is injected and twisted, then the water-blocking tape is wrapped to form a second water-blocking wrapping layer, and the wrapping and covering rate of the second water-blocking wrapping layer is 40% -50%.

4) Extruding the inner sheath on the outer layer of the cable obtained in the step 3), and irradiating and crosslinking the extruded inner sheath by using an electron accelerator; the irradiation makes the thermal extension of the inner sheath and other performances better, and enhances the performance of the final composite cable.

5) Arranging armor outside the inner sheath;

6) and an outer sheath is extruded outside the armor and is subjected to irradiation crosslinking through an electron accelerator. The irradiation enables the thermal extension and other performances of the outer sheath to be better, and the performances of the final composite cable are enhanced.

Preferably, the step of disposing the shielding layer in step 2) includes: and c, filling single-component room temperature vulcanized silica gel into the forming die, lapping a single-sided polyester aluminum foil to form an aluminum foil lapping layer, wherein the aluminum surface faces outwards, the lapping rate of the aluminum foil lapping is 40-50%, then weaving a layer of copper wire containing a plating layer to form a woven shielding layer, and the weaving density is more than or equal to 88%. The single-sided polyester aluminum foil is a process which is easier to realize in batch production.

Advantageous effects

(1) The composite cable integrates a network transmission function and a weak current control transmission function;

(2) the composite cable meets the requirements of longitudinal watertight function, resists longitudinal water pressure of 6.75Mpa, is suitable for ocean environment application, provides power transmission and control signal transmission for submarines, underwater submergence vehicles, detectors, underwater facilities and the like, and has the function of digital network signal transmission;

(3) the comprehensive functions of longitudinal watertight, network signal transmission, power control signal transmission and the like are realized, and the electromagnetic compatibility problem among the longitudinal watertight, network signal transmission, power control signal transmission and the like is solved by utilizing the composite design of the structure.

(4) The double-layer co-extrusion composite insulation has the advantages that the polyethylene is waterproof and moistureproof on the inner layer and is more tightly wrapped with the water-blocking conductor, and the polyolefin is on the outer layer and is more tightly bonded with the water-blocking adhesive by utilizing the performance of the non-polar material, so that the aim of resisting high water pressure is fulfilled. The double-layer scheme improves the strength and safety of insulation.

(5) After glue injection, the aluminum foil and the tinned braided composite shield are adopted, so that the change of the comprehensive dielectric property of the network caused by glue injection is improved, and the network signal can still reach the network transmission property in a glue injection-free state; the double-layer composite shielding increases the mechanical performance of the network unit, so that the structure of the network unit is kept stable in deep sea, and the transmission performance is stable.

(6) The invention is different from the gluing and water blocking mode of the traditional armor, adopts a composite form, and the inside and the outside of the tinned woven armor are wrapped with the water blocking tape, the three layers jointly play the roles of water blocking, armoring, strengthening and protecting, the water blocking performance for deep sea application and the pressure resistance of deep sea are ensured, the armor is not glued, the processing is flexible and controllable, the invention is more suitable for batch industrial implementation, the strength of the water blocking tape of the inside and the outside wrapping is far greater than that of the gluing mode, and the invention has good protection effect on cables under deep sea.

(7) When the cable is formed, room temperature vulcanized silica gel is added, is in a white emulsion state, is non-toxic and non-corrosive, mainly comprises silica gel, a filling agent, a cross-linking agent, an antioxidant and the like, and is in contact with air in a natural environment, then is subjected to cross-linking curing, is adhered to an insulating surface, is tightly adhered to an outer layer polyolefin material, and plays a role in sealing gaps.

In conclusion, the composite cable has better power transmission performance and network transmission performance and is suitable for deep sea underwater navigation.

Drawings

FIG. 1 is a schematic view of a composite cable according to the present invention

FIG. 2 is a schematic diagram of a composite insulated wire core structure according to the present invention

FIG. 3 is a schematic diagram of a power control unit according to the present invention

FIG. 4 is a schematic diagram of a network transmission unit structure according to the present invention

1-a power control unit; 1.1-glue injection conductor; 1.2-composite insulating layer; 1.3-a filler core; 1.4-a first water-blocking wrapping layer; 2-a network transmission unit; 2.1-a conductor; 2.2-insulating layer; 2.3-aluminum foil wrapping layer; 2.4-braiding a shielding layer; 3-a second water-blocking wrapping layer; 4-inner sheath; 5-armoring; 6-outer sheath; 7-composite insulated wire core; 8-network transmission core.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

The present invention will be described in detail below with reference to the attached drawings to facilitate understanding of the present invention by those skilled in the art.

As shown in fig. 1, the longitudinal watertight composite cable for the deep sea underwater vehicle of the present invention comprises a plurality of power control units 1 which are centrally arranged inside, network transmission units 2 which are dispersedly arranged around the power control units 1, and a second water-blocking wrapping layer 3, an inner sheath 4, an armor 5 and an outer sheath 6 which are sequentially arranged on an outer layer.

In the embodiment, the armor 5 is a composite water-blocking armor, and the composite water-blocking armor is formed by wrapping water-blocking tape layers on the inner side and the outer side of a tinned copper wire woven armor to form a sandwich structure of a water-blocking tape, a tinned copper wire woven armor and a water-blocking tape. The armor adopts the wrapping tape that blocks water, and processing is nimble controllable, more is fit for batch industrialization and implements, and the water-blocking tape intensity of inside and outside wrapping is higher, plays better protective effect to the cable under the deep sea. Of course, the tinned copper wire braided armor in the composite water-blocking armor middle layer can also be a copper wire braided armor with other plating layers.

As shown in fig. 3 is a schematic structure diagram of power control unit 1, it can be seen from the figure that power control unit 1 includes two filling cores 1.3, two sets of injecting glue conductors 1.1, and the skin of every group injecting glue conductor 1.1 all is provided with compound insulation layer 1.2 in order to form compound insulation core 7 (fig. 2), still includes that first water blocking winds covering 1.4, and first water blocking winds covering 1.4 and winds two filling cores 1.3 and two sets of compound insulation core 7.

The composite insulating layer 1.2 comprises a polyethylene inner insulating layer and a polyolefin outer insulating layer, and the thickness ratio of the inner insulating layer to the outer insulating layer is 1: 1-2; the polyethylene is waterproof and moistureproof on the inner layer and is more tightly coated with the water-blocking conductor, and the polyolefin is on the outer layer and is more tightly bonded with the water-blocking adhesive by utilizing the performance of the non-polar material, so that the aim of resisting high water pressure is fulfilled.

As shown in fig. 4, which is a schematic structural diagram of the network transmission unit 2, it can be seen from the diagram that the network transmission unit 2 includes a filler core 1.3 and a conductor 2.1, an insulating layer 2.2 is disposed on an outer layer of the conductor 2.1, the conductor 2.1 and the insulating layer 2.2 together form a network transmission core 8, and a shielding layer is disposed on outer layers of the filler core 1.3 and the network transmission core 8; the mode of setting up of shielding layer sets up the shielding layer again after 8 transposition injecting glues of filler core 1.3 and network transmission sinle silk, and the shielding layer includes aluminium foil around covering 2.3 and weave shielding layer 2.4, and the aluminium foil is taken the lid rate and is 40 ~ 50% around covering 2.3, and the thickness of aluminium foil around covering 2.3 is 0.06mm, weaves shielding layer 2.4's weaving density and is not less than 88%. The aluminum foil lapping and the tinned copper wire weaving composite shielding are adopted, so that the change of the comprehensive dielectric property of the network caused by glue injection is improved (the comprehensive dielectric constant inside a network unit formed after shielding is between 2.6 and 3.0, and the attenuation of the network signal can be controlled within a standard range in such a dielectric constant range), and the network signal can still reach the network transmission property in the glue injection-free state; the double-layer composite shielding increases the mechanical performance of the network unit, so that the structure of the network unit is kept stable in deep sea, and the transmission performance is stable.

The preparation process of the composite cable provided by the embodiment of the invention comprises the following steps:

1) preparation of the power control unit 1:

a glue injection conductor 1.1 is formed by stranding a plurality of strands of copper cores containing plating layers and then filling quick-drying neoprene into a stranding die to fill gaps;

b, a compound insulation layer 1.2 consisting of a polyethylene inner insulation layer and a polyolefin outer insulation layer is extruded in a double-layer co-extrusion mode outside the glue injection conductor 1.1, a compound insulation wire core 7 consists of the glue injection conductor 1.1 and the compound insulation layer 1.2, the compound insulation wire core 7 is subjected to irradiation crosslinking, and the thermal extension value of the compound insulation layer after irradiation is less than or equal to 30%;

c, twisting a plurality of composite insulating wire cores 7 with a plurality of filling cores 1.3 to form the power control unit 1, twisting a plurality of power control units 1 into a cable, injecting single-component room temperature vulcanized silica gel in front of a forming die during cable formation, and winding and wrapping a first water-blocking wrapping layer 1.4;

2) preparing the network transmission unit 2:

a, an insulating layer 2.2 is extruded on the outer layer of a conductor 2.1 to form a network transmission wire core 8;

b, twisting a plurality of network transmission wire cores 8 and a plurality of filling cores 1.3;

c, arranging a shielding layer outside the optical cable obtained in the step b to form a network transmission unit 2; the shielding layer in the embodiment is a composite shielding layer consisting of an aluminum foil wrapping 2.3 and a braided shielding 2.4, specifically, after the step b, single-component room-temperature vulcanized silica gel is added in front of a forming die and wrapped by a single-sided polyester aluminum foil d, the aluminum surface faces outwards, the aluminum foil wrapping covering rate is 40% -50%, then a layer of tinned copper wire shielding e is braided by a braiding machine, the braiding density is more than or equal to 88%, and the aluminum foil and the tinned copper wire are braided to form the composite shielding layer together.

3) And (2) uniformly arranging a plurality of network transmission units 2 on the periphery of the stranded cable of the power control unit 1 obtained in the step (1), stranding the stranded cable into a cable, pouring single-component room-temperature vulcanized silica gel in front of a forming die, and wrapping a water-blocking tape to form a second water-blocking wrapping layer 3, wherein the wrapping and covering rate of the water-blocking wrapping tape is 40-50%.

4) Extruding an inner sheath 4 on the outer layer of the cable obtained in the step 3, and irradiating and crosslinking the extruded inner sheath 4 by an electron accelerator;

5) the armor 5 is arranged outside the inner sheath 4, the armor 5 in the embodiment is a composite armor, and the composite water-blocking armor is formed by wrapping water-blocking tape layers inside and outside the woven armor. Therefore, the water blocking tape is wrapped outside the inner sheath during preparation, the tinned copper wire armor is woven on the wrapped water blocking tape by a weaving machine, the weaving density is more than or equal to 80%, the water blocking tape is wrapped outside the armor, and the armor 5 achieving the water blocking effect is formed by the inner water blocking tape, the outer water blocking tape and the middle woven armor layer.

6) An outer sheath 6 is extruded outside the armor 5, and the outer sheath 6 is irradiated and crosslinked by an electron accelerator.

The experimental verification effect of the composite cable prepared by the embodiment of the invention is as follows:

1. longitudinal water tightness test

Experiments prove that the composite cable can achieve the water leakage prevention of 6.75Mpa water pressure of a cable with the length of 1.5 meters. Longitudinal watertight test method: the length of the test sample is 1.5 meters, one end of the test sample is immersed in water of the sealed hydrostatic test device, the other end of the test sample passes through the stuffing box, the contact length of the test sample sheath and the sealant in the stuffing box is 140mm +/-10 mm, then the test sample sheath is pressurized to 6.75MPa of water pressure, the test sample sheath is kept for 2 hours, and no water drops at the end of the cable.

2. Mechanical strength

According to the cable, the water-blocking tapes are respectively added inside and outside the armor layer, the covering rate of the water-blocking tapes is (40-50)%, and the tensile strength of the water-blocking tapes used in the cable is more than or equal to 10 MPa. The two layers of the wrapping tape are added to further protect the cable core, so that the mechanical strength of the cable is enhanced, and meanwhile, the overall flexibility of the cable is increased.

3. Network transmission experiment

Experiments prove that the composite cable can realize underwater high-frequency network signal transmission, the 100-meter distance stable transmission of the gigabit Ethernet and the 50-meter distance stable transmission of the gigabit Ethernet. The vector network analyzer is used for testing indexes of characteristic impedance, attenuation, equal-level far-end crosstalk, equal-level near-end crosstalk and the like of a 100-meter cable in a frequency range of 4-250 MHz respectively, and the indexes all meet the standard transmission requirements of 'YD/T1019-2013 polyolefin insulation level twisted pair cable for digital communication'. The indexes of characteristic impedance, attenuation, equal-level far-end crosstalk, equal-level near-end crosstalk and the like of a 50-meter cable in a frequency range of 4-500 MHz are tested, and the standard requirements of YD/T1019-2013 polyolefin insulation level twisted pair cable for digital communication are met.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.