Longitudinal airtight transverse watertight high-temperature-resistant cable and preparation method thereof

Abstract

The invention discloses a longitudinal airtight transverse watertight high-temperature-resistant cable which comprises main cable cores, a filling layer, a cable core wrapping layer, an inner sheath, an armor layer and an outer sheath. The main wire core is of a 3 + 9 structure; the three main wire cores and the four filling ropes are twisted to form an inner cable core, one filling rope is located in the center, and the other three filling ropes are located between the outer sides of the two adjacent main wire cores respectively. The other nine main wire cores and filling ropes with the number two times that of the main wire cores are twisted outside the inner cable core to form an outer cable core. The filling ropes of the inner cable core and the filling ropes of the outer cable core form a filling layer together, and the filling ropes of the inner cable core and the filling ropes of the outer cable core form a filling layer together, and the filling ropes of the inner cable core and the filling ropes of the outer cable core are arranged between the inner sides of the corresponding two adjacent main cable cores of the 9 main cable cores. The cable core wrapping layer is wrapped outside the outer cable core; the inner sheath is extruded outside the cable core wrapping layer by adopting cross-linked polyolefin; the armor layer is a metal armor layer formed by weaving metal wires outside the inner sheath; and the outer sheath is extruded outside the armor layer by adopting cross-linked polyolefin.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a longitudinally airtight and transversely watertight high-temperature resistant cable and its preparation method. Background Technology

[0002] Marine power cables are prone to leakage due to their harsh operating environment, often exposed to seawater. Damage to the cable itself can easily lead to leaks. In the event of other unforeseen accidents, subsaturated water vapor and other harmful gases can easily diffuse longitudinally along the cable, becoming a source of leakage. Conventional rubber power cables struggle to achieve airtightness in the cable core. While the sheathing material can partially fill the gaps between the multiple cylindrical cores during cable extrusion, it's difficult to reliably fill the gaps at the contact points of the cores, thus posing a risk of leakage. Chinese patent document CN106653191B discloses a longitudinally watertight and airtight cable and its manufacturing method. The cable's structure includes seven sets of insulated cores, a filler, an inner liner, an armor layer, and an outer sheath. The seven sets of insulated cores are wrapped around the inner liner, which is then wrapped around an armor layer formed by braiding tinned copper wire at an angle of 50°-60°. The armor layer is then wrapped around an outer sheath, filling the gaps between the insulated cores and the inner liner, as well as between different sets of insulated cores. An automated, continuous glue-filling process is used, employing a special mold with a pressure-holding sleeve design and a reflux-type glue-filling groove shape to fill the gaps between the insulated cores. After cable formation, sealing tape is promptly wrapped around the cable. However, glue filling may result in gaps, and the glue itself requires high quality. During installation, the glue may also be damaged or break, leading to sealing failure. Existing technologies often use compressed filler ropes for filling, which is easier when there are three main cores, requiring filling in the middle and outer perimeter. When the main conductor adopts a 3+N or 3+N+N structure, that is, there are multiple layers of main conductors, the filling between the outer main conductors becomes more difficult. In actual production, certain problems have been found: Using side-filling (side-filling refers to filling rope a and unit conductor b (the unit conductor is also the main conductor) being on a circle of the same radius, see...) Figure 1The gaps between the cable unit cores (b) are small, and the dividing reels used in conventional compression filler rope processes are the same as those used in conventional cabling. This creates a problem: the main pressure on the filler comes from the cores on its left and right sides, resulting in high pressure and a high compression ratio (compression ratio = filler rope cross-sectional area / corresponding filler gap area) only in the middle section, leading to tight filling. The filler material on the outer side of the cable unit core (100mm) is less, and the compression ratio is low, resulting in substandard airtightness. Furthermore, being sandwiched between two unit cores can contribute to an overall larger cable outer diameter. Chinese patent document CN206639599U discloses an airtight cable comprising a copper conductor composed of multiple strands of oxygen-free copper strands, with the gaps between the strands filled with a special liquid silicone gel that solidifies to form an airtight structure. The copper conductor is covered by a cross-linked polyethylene insulation layer, within which the special liquid silicone gel is sealed and filled. The cross-linked polyethylene insulation layer is further covered by a halogen-free, low-smoke, flame-retardant inner sheath, within which a water-blocking buffer layer is provided. This water-blocking buffer layer is a mixture of water-blocking paste and water-blocking powder. The halogen-free, low-smoke, flame-retardant inner sheath is further covered by a halogen-free, low-smoke, flame-retardant outer sheath, with an aluminum-polyethylene adhesive layer between the outer and inner sheaths. This structure exhibits good airtightness, but its lateral watertightness is poor; the liquid silicone gel is easily damaged laterally, leading to leakage and posing a safety hazard. Summary of the Invention

[0003] The purpose of this invention is to provide a high-temperature resistant cable with a simple structure, good sealing effect, longitudinal airtightness, and transverse watertightness, and its preparation method.

[0004] The basic technical solution for achieving the objective of this invention is: a longitudinally airtight and laterally watertight high-temperature resistant cable, comprising a main core, a filler layer, a core wrapping layer, an inner sheath, an armor layer, and an outer sheath. The main core has a 3+9 structure, with each main core having the same structure, including two cores, core filler, and core wrapping; each core includes a core conductor and core insulation; the core conductor is extruded with cross-linked polyethylene material to form core insulation; two cores and two filler ropes are twisted together to form a cable, with the two filler ropes forming corresponding core fillers; three main cores and four filler ropes are twisted together to form an inner cable core, with one filler rope located in the center and the other three located on the outer sides of adjacent two main cores; the remaining nine main cores are twisted together with twice the number of filler ropes. An outer core is formed outside the inner core; 18 filler ropes are divided into two groups, one group of 9 ropes is located between the inner sides of the corresponding two adjacent main cores of the 9 main cores, and the other group of 9 ropes is located between the outer sides of the corresponding two adjacent main cores of the 9 main cores. The filler ropes of the inner core and the filler ropes of the outer core together form a filler layer; the core wrapping layer is wrapped around the outer core; the inner sheath is made of cross-linked polyolefin extruded around the core wrapping layer; the armor layer is made of metal wire braided around the inner sheath to form a metal armor layer; the outer sheath is made of cross-linked polyolefin extruded around the armor layer.

[0005] Furthermore, to improve reliability, a leaky wire is also included, in which nine main cores are twisted together with twice the number of filler ropes to form an outer core while a leaky wire is directly attached.

[0006] Furthermore, to improve high temperature resistance: the cable core wrapping layer includes a first wrapping layer and a second wrapping layer. The first wrapping layer uses polyimide film wrapped around the main cable core, with a wrapping overlap rate of less than or equal to 30%. The second wrapping layer uses aluminum-plastic tape wrapped around the first wrapping layer, with a wrapping overlap rate of less than or equal to 30%.

[0007] Furthermore, to improve airtightness, the filling rope is a non-hygroscopic, flexible, environmentally friendly PP rope.

[0008] Furthermore, to improve high temperature resistance: after the two core wires and two filler ropes are twisted into a cable, a layer of polyimide film is wrapped around them to form a core wrap, with an overlap rate of not less than 30%.

[0009] A method for manufacturing a longitudinally airtight and laterally watertight high-temperature resistant cable includes the following steps: 1) Making the wire core Several tinned copper wire bundles are twisted and then re-twisted to form a core conductor. Cross-linked polyethylene material is extruded over the core conductor to form core insulation. 2) Fabrication of the main wire core Two core wires and two filler ropes are twisted together to form a cable, and then wrapped with a layer of polyimide film to form a core wrap. The two filler ropes form the corresponding core filler. 3) Fabrication of the main cable core The main cable core consists of an inner cable core and an outer cable core. Three main cable cores and four filler ropes are twisted together to form a cable. One filler rope is located in the center, and the other three are located on the outside of two adjacent main cable cores. They are then twisted together with the main cable cores to form the inner cable core. The other nine main cable cores and eighteen filler ropes are twisted together outside the inner cable core to form the outer cable core. 4) Fabricate the cable core cladding The cable core wrapping layer includes a first wrapping layer and a second wrapping layer. The first wrapping layer uses polyimide film wrapped around the outside of the main cable core, with a wrapping overlap rate of less than or equal to 30%. The second wrapping layer uses aluminum-plastic tape wrapped around the outside of the first wrapping layer, with a wrapping overlap rate of less than or equal to 30%. 5) Making the inner sheath Cross-linked polyolefin is extruded onto the outside of the cable core wrapping layer to form an inner sheath; 6) Create armor layers A metal armor layer is formed on the outside of the inner sheath by weaving metal wires, with a weaving coverage of 80% to 90%. 7) Making the outer sheath Cross-linked polyolefin is extruded onto the outside of the armor layer.

[0010] To achieve filling on both sides, step 3) uses a positioning tray to position each main conductor and each filling rope: First, the first cage-type cable-forming machine is used to twist the three main conductors and four filler ropes into an inner cable core. Then, the inner cable core, 9 main wire cores, and 18 filler ropes are twisted together to form the main cable core. At this time, the 9 main wire cores and 18 filler ropes form the corresponding outer cable core. During the stranding of the outer cable cores, a positioning turntable is used to position each main cable core and each filler rope. The positioning turntable is a frustum-shaped shell, and its size increases along the cable's forward direction. The positioning turntable has three sets of threading holes, one set for the cable cores and the other two sets for the filler ropes. An inner cable core hole is located in the center of the positioning turntable. The cable core holes are set at equal angular intervals along the circumference of the positioning turntable. One set of filler rope holes is set at equal angular intervals along the circumference of the positioning turntable, with a radius smaller than that of the cable core holes, and each filler rope hole is located radially between two adjacent cable core holes. Another set of filler rope holes is set at equal angular intervals along the circumference of the positioning turntable, with a radius larger than that of the cable core holes, and each filler rope hole is located radially between two adjacent cable core holes. That is, the corresponding two filler rope holes in each of the two sets of filler rope holes are on the same radial direction.

[0011] The present invention has the following beneficial effects: (1) The longitudinal airtight and transverse watertight high temperature resistant cable of the present invention has a simple structure and a good sealing effect. During cabling, the flexible filler rope with good compressibility is twisted together with the core unit. The filler rope undergoes plastic deformation under twisting pressure, tightly squeezes and fills all gaps, thereby achieving permanent physical sealing through a purely mechanical structure, meeting the airtight requirements. By blocking or delaying moisture, corrosive or other harmful gases through longitudinal airtightness, it can protect the cable and target equipment from short circuits or corrosion, which will greatly improve the service life of the cable or equipment.

[0012] (2) The longitudinal airtight and transverse watertight high temperature resistant cable of the present invention adopts the inner and outer side filling method, which breaks through the traditional positive side filling method, so that the filling rope is squeezed towards the middle small gap; it can achieve more filling in the large gap and less filling in the small gap, the compression ratio is more uniform, the filling is full and compact, thereby improving the airtight effect.

[0013] (3) The inner and outer sheaths of the longitudinal airtight and transverse watertight high temperature resistant cable of the present invention are both made of cross-linked polyolefin material, which has good water resistance. Both the inner and outer sheaths are subjected to water absorption test. The test is conducted in accordance with the requirements of 9.2 (weight test) in GB / T2951.13-2008. The results show that the maximum weight change rate is ≤5mg / cm2 at a temperature of 0±2℃ and a time of 336h.

[0014] (4) A transverse watertightness test was conducted on the longitudinally airtight and transversely watertight high-temperature resistant cable of the present invention. The test steps are as follows: a. Pass one end of the specimen through the packing tube of the hydrostatic test vessel and out through the other packing tube, and seal the specimen with a suitable assembly; b. Fill the pressure vessel with water to raise the water pressure to the specified value of 22.5 MPa; c. After the water pressure reaches the specified value, it should be stored for no less than the specified time of 6 hours; d. Reduce the water pressure, remove the sample, and inspect the sample end that was subjected to the water pressure; The results of the above experiments are as follows: a. The volume of water leaking from the free end of the sample should conform to the requirements of Table 4 in GJB1916A-2022; b. Any component subjected to water pressure shall be free from any visible damage, and its insulation resistance and conductor resistance shall meet the requirements of Tables 5 and 2 in GJB774A-2020.

[0015] (5) The insulation and sheath materials of the longitudinally airtight and transversely watertight high-temperature resistant cable of the present invention are made of materials with higher temperature ratings, and the insulation core is wrapped with a polyimide film, which has good high-temperature resistance. During the test, the cable sample is first placed in an aging chamber according to the corresponding bending radius for accelerated thermal aging test. The test conditions are 165℃ / 240h. After the test, the cable is observed, and it is required that no component of the cable is cracked or stuck, and the appearance is good. Then, the aged (165℃ / 240h) sample is passed through the silicone seal in a U-shape and matched with the electrical penetration component and installed on the test chamber. Saturated steam is introduced into the test chamber to make the temperature in the chamber reach 152℃ and the pressure is maintained at 0.56MPa. Under the action of high temperature and high pressure, the cable withstands the compression of the silicone seal for 50h and the sealing condition of the cable seal is observed. After the test, the test cable is tested for voltage resistance according to the "conventional test" and there is no breakdown.

[0016] (6) The armor layer of the longitudinal airtight and transverse watertight high temperature resistant cable of the present invention is made of tin-plated copper wire braid (braid coverage reaches more than 90%), which is more flexible and has a better shielding effect than traditional steel tape armor.

[0017] (7) This invention is a new process that breaks through the traditional process of relying on pressure to squeeze the filler outward from narrow gaps. The traditional process not only results in insufficient filling on the outside, but also too much thickness in the middle, which increases the outer diameter of the cable. The process of this invention achieves filling on the inner and outer sides of the wire core by adding a positioning turntable, so that the filler appears in the appropriate gap and fills the gap in the middle. This not only results in full filling and better airtightness, but also helps to reduce the overall radius of the cable, making it more suitable for applications with limited space on ships.

[0018] (8) The core advantage of the longitudinally airtight and transversely watertight high-temperature resistant cable of the present invention is that it can ensure the stability and safety of signal and power transmission in harsh environments such as high temperature, humidity, and even immersion in water, while possessing excellent structural protection performance. Firstly, the cable is longitudinally airtight, which can prevent gas penetration, ensure insulation and structural stability, and prevent the internal insulation layer and filling layer of the cable from developing gaps or bulges due to gas intrusion, thus preventing a decline in insulation performance. It is especially suitable for scenarios where there are flammable or corrosive gases, such as oil and gas extraction, mines, and chemical pipelines. It prevents electrochemical corrosion of the cable's metal sheath / armor caused by gas penetration, extending the cable's service life.

[0019] Secondly, the cable's lateral watertightness prevents radial intrusion of external moisture, adapting to humid / water-immersed environments. Even if the cable sheath is partially damaged due to wear or compression, moisture cannot penetrate radially into the cable, preventing conductor short circuits, insulation breakdowns, and other faults. It can be directly applied to underwater installations (such as submarine communications and underwater equipment power supply), underground damp tunnels, and coastal high-salt-spray environments where long-term contact with moisture is required, without the need for additional complex waterproof sleeves.

[0020] Finally, the cable exhibits excellent high-temperature resistance, enabling it to withstand high-temperature operating conditions and broaden its application scenarios. It maintains stable electrical performance and mechanical strength in high-temperature environments (typically withstanding 150℃ and above), without softening, decomposition, or accelerated aging of the insulation layer due to high temperatures. It is suitable for high-temperature operating areas such as metallurgy, thermal power, glass manufacturing, and industrial kilns, as well as fields with strict temperature resistance requirements such as aerospace and new energy vehicles. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the filling method of the filling rope in the prior art.

[0022] Figure 2 This is a schematic diagram of the longitudinal airtight and transverse watertight high-temperature resistant cable of the present invention.

[0023] Figure 3 This is a schematic diagram of the filling device in the method for preparing a longitudinally airtight and laterally watertight high-temperature resistant cable according to the present invention.

[0024] Figure 4 for Figure 3 A diagram showing the view from the right.

[0025] Figure 5 From Figure 3 A three-dimensional diagram for viewing from the upper right.

[0026] Figure 6 This is a schematic diagram of the structure of the filling rope of the present invention using a two-sided filling method.

[0027] Figure 7This is a schematic diagram of the structure after filling. The filling part is indicated by the location of the filling rope, but in reality, the entire structure is filled.

[0028] The labels in the attached diagram are: Main core 1, core 1-1, core conductor 1-11, core insulation 1-12, core filler 1-2, core wrapping 1-3 Fill layer 2, Cable core sheath 3, first sheath 3-1, second sheath 3-2. Inner sheath 4, Armor layer 5, Outer sheath 6, Leakage line 7, Positioning turntable 10, wire core hole 10-1, filling rope hole 10-2. Detailed Implementation

[0029] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. The orientation of the invention is described according to... Figure 2 The orientation shown on the cable cross-section is as follows, that is... Figure 2 The up, down, left, and right directions shown are the radial directions described. Figure 2 The direction to which the object faces is the axial direction. Terms such as "upper," "lower," "inner," and "outer" indicate orientation or positional relationship based on the positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention or simplifying the description, rather than indicating a specific orientation that must be present.

[0030] (Example 1) See Figure 2 The longitudinally airtight and transversely watertight high-temperature resistant cable of the present invention includes a main core 1, a filling layer 2, a core wrapping layer 3, an inner sheath 4, an armor layer 5, an outer sheath 6, and a leakage wire 7.

[0031] The main core 1 has a 3+9 structure, meaning there are 3 main cores 1 in the inner layer and 9 main cores in the outer layer. In this embodiment, there are 12 main cores 1, and all 12 main cores 1 have the same structure, including two cores 1-1, core filler 1-2, and core wrapping 1-3. Core 1-1 includes a core conductor 1-11 and core insulation 1-12. The core conductor 1-11 is formed by stranding several metal monofilaments. In this embodiment, the metal monofilaments are tinned copper wires. The core conductor 1-11 is extruded with cross-linked polyethylene material to form the core insulation 1-12. The cross-linked polyethylene is a 125°C irradiated cross-linked polyethylene insulation material, and its temperature rating is 125°C. Two core wires 1-1 and two filler ropes are twisted into a cable and then wrapped with a layer of polyimide film to form core wrap 1-3. The two filler ropes form corresponding core fillers 1-2. The filler ropes are non-hygroscopic flexible environmentally friendly PP ropes (polypropylene material). The polyimide film of the core wrap 1-3 adopts FP-PI-FP composite and the overlap rate is not less than 30%.

[0032] Three main conductor cores 1 and four filler ropes are twisted together to form a cable. One filler rope is located in the center, and the other three are located between the outer sides of two adjacent main conductor cores 1. These filler ropes are then twisted together with the main conductor cores 1 to form the inner cable core. The remaining nine main conductor cores 1 and twice the number of filler ropes (i.e., 18 filler ropes) are twisted around the inner cable core to form the outer cable core, which is directly connected to a leaky wire 7. The inner and outer cable cores together constitute the main cable core. The 18 filler ropes are divided into two groups: one group of nine ropes is located between the inner sides of corresponding adjacent main conductor cores 1, and the other nine ropes are located between the outer sides of corresponding adjacent main conductor cores 1 (see [link to relevant documentation]). Figure 6 and Figure 7 The filler ropes of the inner cable core and the filler ropes of the outer cable core together form the filler layer 2.

[0033] The cable core wrapping layer 3 includes a first wrapping layer 3-1 and a second wrapping layer 3-2. The first wrapping layer 3-1 is made of polyimide film wrapped around the main cable core, with a wrapping overlap rate of less than or equal to 30%. The second wrapping layer 3-2 is made of aluminum-plastic tape wrapped around the first wrapping layer 3-1, with a wrapping overlap rate of less than or equal to 30%. This embodiment uses double-layer wrapping. The core function of the polyimide film in the first wrapping layer 3-1 is to enhance insulation performance, improve high-temperature resistance and aging resistance, and ensure stable operation of the cable under severe conditions. The advantages of this material are its excellent high-temperature resistance, excellent electrical insulation performance, outstanding weather resistance and chemical stability, and good physical and mechanical properties. The core function of the aluminum-plastic tape in the second wrapping layer 3-2 is to achieve electromagnetic shielding, ensure stable signal transmission, and improve the safety of cable operation. Its advantages are balanced shielding effect, cost-effectiveness, integrated moisture protection and shielding, simplified process, light weight, good flexibility, excellent corrosion resistance, and wide range of applications.

[0034] The inner sheath 4 is made of cross-linked polyolefin extruded onto the outside of the cable core wrapping layer 3. The cross-linked polyolefin is a 90°C irradiated cross-linked polyolefin sheath material.

[0035] The armor layer 5 is formed by weaving metal wires on the outside of the inner sheath 4 to form a metal armor layer, with a weaving coverage of 80% to 90%. In this embodiment, the metal wires are tin-plated copper wires.

[0036] The outer sheath 6 is made of cross-linked polyolefin extruded over the armor layer 5. The cross-linked polyolefin is a 90°C irradiated cross-linked polyolefin sheath material.

[0037] See Figures 3 to 7 The method for preparing a longitudinally airtight and transversely watertight high-temperature resistant cable includes the following steps: 1) Making wire core 1-1 Several tinned copper wire bundles are twisted and then re-twisted to form core conductor 1-11. Cross-linked polyethylene material is extruded over core conductor 1-11 to form core insulation 1-12.

[0038] 2) Fabrication of main wire core 1 Two core wires 1-1 and two filler ropes are twisted together to form a cable, and then wrapped with a layer of polyimide film to form core wrap 1-3. The two filler ropes form the corresponding core filler 1-2.

[0039] 2.1) Further, the filling rope is a non-hygroscopic flexible environmentally friendly PP rope (polypropylene material), and the polyimide film wrapped around the core 1-3 is FP-PI-FP composite with an overlap rate of not less than 30%.

[0040] 3) Fabrication of the main cable core The main cable core consists of an inner cable core and an outer cable core. Three main cable cores 1 and four filler ropes are twisted together to form a cable. One filler rope is located in the center, and the other three are located on the outside of two adjacent main cable cores 1, and then twisted together with the main cable cores 1 to form the inner cable core. The other nine main cable cores 1 and 18 filler ropes are twisted together outside the inner cable core to form the outer cable core.

[0041] First, the first cage-type cable forming machine is used to twist the three main conductor cores 1 and the four filler ropes into an inner cable core; Then, the inner cable core, the 9 main cores 1, and the 18 filler ropes are twisted together to form the main cable core. At this time, the 9 main cores 1 and the 18 filler ropes form the corresponding outer cable core. During the outer cable core stranding process, the positioning turntable 10 positions each main core 1 and filler rope 2, and then the stranding is performed, with a leakage wire 7 being directly dragged during stranding. The positioning turntable 10 is a frustum-shaped shell, and its size increases along the cable's forward direction. The positioning turntable 10 has three sets of threading holes, one set for core holes 10-1 and the other two sets for filler rope holes 10-2. An inner cable core hole is located in the center of the positioning turntable 10. Each core hole 10-1 is angularly spaced along the circumference of the positioning turntable 10. A set of filler rope holes 10-2 is angularly spaced along the circumference of the positioning turntable 10, with a radius smaller than the radius of the core holes 10-1, and each filler rope hole 10-2 is radially located between two adjacent core holes 10-1. Another set of filling rope holes 10-2 are arranged at equal intervals along the circumference of the positioning turntable 10. Their radius is larger than that of the wire core hole 10-1, and each filling rope hole 10-2 is located radially between two adjacent wire core holes 10-1. That is, the corresponding two filling rope holes 10-2 in each of the two sets are on the same radial direction. This results in filling from the inner and outer edges (the inner and outer edges refer to circles with different radii for the filling rope 2 and the main wire core 1) towards the smaller gaps in the middle, achieving a more uniform compression ratio where larger gaps are filled and smaller gaps are filled less.

[0042] 4) Fabricate the cable core cladding layer 3 The cable core wrapping layer 3 includes a first wrapping layer 3-1 and a second wrapping layer 3-2. The first wrapping layer 3-1 is wrapped with polyimide film around the main cable core, with a wrapping overlap rate of less than or equal to 30%. The second wrapping layer 3-2 is wrapped with aluminum-plastic tape around the first wrapping layer 3-1, with a wrapping overlap rate of less than or equal to 30%.

[0043] 5) Make the inner sheath 4 Cross-linked polyolefin is extruded onto the outside of the cable core wrapping layer 3 to form an inner sheath.

[0044] 5.1) Further, the cross-linked polyolefin is an irradiated cross-linked polyolefin.

[0045] 6) Craft armor layer 5 A metal armor layer 5 is formed on the outside of the inner sheath 4 by weaving metal wires, with a weaving coverage of 80% to 90%.

[0046] 6.1) Further, the metal wire is made of tin-plated copper wire.

[0047] 7) Make the outer sheath 6 Cross-linked polyolefin is extruded onto the outer layer 5 of the armor.

[0048] 7.1) Further, the cross-linked polyolefin is an irradiated cross-linked polyolefin.

[0049] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A longitudinally airtight and laterally watertight high-temperature resistant cable, characterized in that: It includes the main core (1), the filling layer (2), the core wrapping layer (3), the inner sheath (4), the armor layer (5), and the outer sheath (6); The main core (1) has a 3+9 structure, and each main core (1) has the same structure, including two cores (1-1), core filler (1-2), and core wrapping (1-3); the core (1-1) includes a core conductor (1-11) and core insulation (1-12); the core conductor (1-11) is extruded with cross-linked polyethylene material to form core insulation (1-12); the two cores (1-1) and two filler ropes are twisted into a cable, and the two filler ropes form corresponding core fillers (1-2); the three main cores (1) and four filler ropes are twisted into an inner cable core. One filler rope is located in the center, and the other three are located between the outer sides of two adjacent main cores (1); the other nine main cores (1) are twisted together with twice the number of filler ropes outside the inner core to form the outer core; the 18 filler ropes are divided into two groups, one group of nine ropes is located between the inner sides of the corresponding two adjacent main cores (1) of the nine main cores (1), and the other nine ropes are located between the outer sides of the corresponding two adjacent main cores (1) of the nine main cores (1). The filler ropes of the inner core and the filler ropes of the outer core together form the filler layer (2); the core wrapping layer (3) is wrapped around the outer core; The inner sheath (4) is made of cross-linked polyolefin extruded outside the cable core wrapping layer (3); The armor layer (5) is formed by weaving metal wires on the outside of the inner sheath (4) to form a metal armor layer; The outer sheath (6) is made of cross-linked polyolefin extruded over the armor layer (5).

2. The longitudinally airtight and laterally watertight high-temperature resistant cable according to claim 1, characterized in that: It also includes a leak line (7), where 9 main cores (1) are twisted together with twice the number of filler ropes to form an outer core while a leak line (7) is directly pulled.

3. The longitudinally airtight and laterally watertight high-temperature resistant cable according to claim 1, characterized in that: The cable core wrapping layer (3) includes a first wrapping layer (3-1) and a second wrapping layer (3-2). The first wrapping layer (3-1) is wrapped with polyimide film outside the main cable core, and the wrapping overlap rate is less than or equal to 30%. The second wrapping layer (3-2) is wrapped with aluminum-plastic tape outside the first wrapping layer (3-1), and the wrapping overlap rate is less than or equal to 30%.

4. The longitudinally airtight and laterally watertight high-temperature resistant cable according to claim 1, characterized in that: The filler rope is a non-hygroscopic, flexible, environmentally friendly PP rope.

5. The longitudinally airtight and laterally watertight high-temperature resistant cable according to claim 1, characterized in that: Two core wires (1-1) and two filler ropes are twisted together to form a cable, and then wrapped with a layer of polyimide film to form a core wrap (1-3), with an overlap rate of not less than 30%.

6. A method for preparing a longitudinally airtight and transversely watertight high-temperature resistant cable, comprising the following steps: 1) Making the wire core (1-1) Several tinned copper wire bundles are twisted and then re-twisted to form a core conductor (1-11). Cross-linked polyethylene material is extruded over the core conductor (1-11) to form core insulation (1-12). 2) Making the main wire core (1) Two core wires (1-1) and two filler ropes are twisted together to form a cable and then wrapped with a layer of polyimide film to form a core wrap (1-3). The two filler ropes form the corresponding core filler (1-2). 3) Fabrication of the main cable core The main cable core consists of an inner cable core and an outer cable core. Three main wire cores (1) and four filler ropes are twisted together to form a cable. One filler rope is located in the center, and the other three are located on the outside of two adjacent main wire cores (1) respectively. They are then twisted together with the main wire cores (1) to form the inner cable core. The other nine main wire cores (1) and eighteen filler ropes are twisted together outside the inner cable core to form the outer cable core. 4) Fabricate the cable core cladding (3) The cable core wrapping layer (3) includes a first wrapping layer (3-1) and a second wrapping layer (3-2). The first wrapping layer (3-1) is wrapped with polyimide film around the main cable core, with a wrapping overlap rate of less than or equal to 30%. The second wrapping layer (3-2) is wrapped with aluminum-plastic tape around the first wrapping layer (3-1), with a wrapping overlap rate of less than or equal to 30%. 5) Making the inner sheath (4) Cross-linked polyolefin is extruded onto the outside of the cable core wrapping layer (3) to form an inner sheath; 6) Create the armor layer (5) A metal armor layer (5) is formed on the outside of the inner sheath (4) by weaving metal wires, with a weaving coverage of 80% to 90%; 7) Making the outer sheath (6) Cross-linked polyolefin is extruded onto the outside of the armor layer (5).

7. The method for preparing a longitudinally airtight and transversely watertight high-temperature resistant cable according to claim 6, wherein in step 3), a positioning tray (10) is used to position each main conductor (1) and each filler rope: First, the first cage-type cable forming machine is used to twist the three main cores (1) and four filler ropes into an inner cable core; Then, the inner cable core, the 9 main wire cores (1), and the 18 filler ropes are twisted together to form the main cable core. At this time, the 9 main wire cores (1) and the 18 filler ropes form the corresponding outer cable core. When the outer cable cores are twisted, each main core (1) and each filler rope (2) is positioned by a positioning turntable (10); the positioning turntable (10) is a frustum shell, and the positioning turntable (10) is arranged from small to large along the cable advancing direction; the positioning turntable (10) is provided with three sets of wire holes, one set of which is the core hole (10-1), and the other two sets are filler rope holes (10-2); the positioning turntable (10) is provided with an inner cable core hole in the middle; each core hole (10-1) is arranged at equal intervals along the circumference of the positioning turntable (10); a set of filler rope holes (10-2) is arranged at equal intervals along the circumference of the positioning turntable (10). The interval angle is set such that its radius is smaller than the radius of the wire core hole (10-1), and each filling rope hole (10-2) is located in the middle of two adjacent wire core holes (10-1) in the radial direction; another set of filling rope holes (10-2) is set at equal intervals along the circumference of the positioning turntable (10), its radius is larger than the radius of the wire core hole (10-1), and each filling rope hole (10-2) is located in the middle of two adjacent wire core holes (10-1) in the radial direction, that is, the corresponding two filling rope holes (10-2) of the two sets of filling rope holes (10-2) are on the same radial direction.

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