Multi-strand stranded multi-core cable and manufacturing process thereof

Abstract

The invention relates to the technical field of cable production, in particular to a multi-strand stranded multi-core cable, which comprises a main core and auxiliary cores wound outside the main core, a filling layer is filled between the main core and the auxiliary cores, the main core is provided with one and serves as a central strand, six auxiliary cores are stranded outside the main core, insulating layers are wound outside the auxiliary cores, and the insulating layers are wound outside the auxiliary cores. According to the multi-core cable, the multi-core cable is adopted, the skin effect of the cable is avoided, the power consumption of the cable is reduced, meanwhile, the cable core filling paste is filled in and out of the combined cable core, the cable core filling paste is filled in and out of the combined cable core, and the cable core filling paste is not prone to falling off, so that the service life of the cable is prolonged. Therefore, the cavity at the contact part of the main core and the auxiliary core is filled, the internal gap of the combined cable core is effectively reduced, and the structural strength and the filling density of the combined cable core are ensured; the invention further provides a manufacturing process of the multi-strand stranded multi-core cable suitable for the multi-strand stranded multi-core cable.

Description

Technical Field

[0001] The invention relates to the technical field of cable production, in particular to a multi-strand twisted multi-core cable and a manufacturing process thereof. Background Art

[0002] Multi-core cable refers to a cable with more than one insulated core. Single-core cable has skin effect, that is, when there is alternating current or alternating electromagnetic field in the conductor, the current inside the conductor is unevenly distributed, and the current is concentrated in the "skin" part of the conductor, that is, the current is concentrated in the thin layer on the surface of the conductor. The closer to the surface of the conductor, the greater the current density. The current inside the conductor is actually smaller, which increases the resistance of the conductor and its power loss. In the prior art, single-core cables have obvious skin effect and large line loss when there is alternating current or alternating electromagnetic field. Multi-core cables refer to cables with more than one insulated core, which can effectively reduce the skin effect of the cable, thereby reducing the line loss and improving the transmission efficiency of the cable. For example, Chinese patent CN202110850537.7 discloses a multi-strand twisted carbon fiber composite cable and its manufacturing process, which adopts a multi-strand twisted carbon fiber composite optical fiber structure and a multi-strand twisting method of carbon fiber composite materials. Its structure includes a plastic / stainless steel tube optical unit, a high modulus carbon fiber composite core rod, a carbon fiber / optical composite core rod, a weather-resistant silicone rubber filling layer, a copper / aluminum stranded wire, and an outer insulation layer. The multi-strand twisted carbon fiber composite cable and its manufacturing process provide structural space for large-capacity optical fibers by adopting a multi-strand twisted carbon fiber composite optical fiber structure, and adopt a multi-strand twisting method of carbon fiber composite materials to improve the strength of the structure. However, the strands of different materials are intertwined to form a whole, and the structural strength and thermal stability are poor. When subjected to external force impact, stress concentration is easily generated, causing local short-circuit cable overheating.

[0003] Therefore, it is necessary for those skilled in the art to provide a multi-strand twisted multi-core cable and a manufacturing process thereof to improve the uniformity and stability of the structural distribution, thereby ensuring the compression resistance and impact resistance. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-strand twisted multi-core cable and its manufacturing process, so as to solve the technical problem that the multi-core cable in the prior art uses multiple strands of twisted wires of different materials to be twisted together, and its structural strength and thermal stability are poor. When subjected to external force impact, stress concentration is easily generated, resulting in local short circuit and cable overheating.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A multi-core cable with multiple strands is provided, comprising a main core and a secondary core wrapped around the outside of the main core, a filling layer is filled between the main core and the secondary core, the main core is provided with one strand as a central strand, seven secondary cores are twisted around the outside of the main core, an insulating layer is wrapped around the outside of the secondary core, a weather-resistant layer is provided outside the insulating layer, a shielding layer is provided outside the weather-resistant layer, an anti-corrosion layer is provided outside the shielding layer, and a wear-resistant layer is provided outside the anti-corrosion layer.

[0007] Furthermore, the filling layer is a cable core filling paste, and cavities are formed between the main core and the auxiliary core and between the auxiliary core and the insulating layer, and the cable core filling paste is filled into the cavities.

[0008] Furthermore, the weather-resistant layer is sprayed outside the insulating layer, and the material of the weather-resistant layer includes silicone rubber. The shielding layer is made of tinned copper. The anti-corrosion layer is made of soft polyvinyl chloride, and the wear-resistant layer is extruded from low-smoke halogen-free polyolefin.

[0009] A manufacturing process for a multi-strand twisted multi-core cable, which is applicable to any of the multi-strand twisted multi-core cables described above, comprising: S1: processing the conductive material into a desired shape and size through processes such as stretching, straightening, and cutting to obtain a main core and a secondary core; S2: heating the cable core filling paste to 120-220°C to melt it into a molten state, using a traction device to pull the main core and the secondary core to be immersed in the cable core filling paste, the main core passes through the cable core filling paste at a speed of 10-15m / min, and the secondary core passes through the cable core filling paste at a speed of 10-15m / min, completing the preliminary coating of the main core and the secondary core; S3: before the cable core filling paste on the surface of the main core and the secondary core is solidified, using a traction device and a back-twisting cage twisting device The main core and the auxiliary core are twisted into one, wherein the main core is used as the central strand and the auxiliary core is wound around the main core to form a "1+6" twisted structure to obtain a combined cable core; S4: The cable core filling paste is heated to 140-280°C, and the combined cable core is pulled into the cable core filling paste by a pulling device, and the combined cable core passes through the cable core filling paste at a speed of 10-15m / min, so that the inside and outside of the combined cable core are filled with the cable core filling paste, and the combined cable core is uniformly cooled and solidified at a cooling rate of 10-20°C / min to complete the coating of the filling layer to obtain a conductor; S5: The conductor is passed into an extruder by a pulling device, and the extrusion temperature of the extruder is dynamically adjusted within the range of 80-90°C and the pressure is adjusted within the range of 10-20°C / min. S6: using a traction device to pass the insulating conductor into an extruder, dynamically adjusting the extrusion temperature of the extruder within the range of 180 to 210°C and the pressure within the range of 60 to 180 bar, using high temperature and high pressure to form a uniform weather-resistant layer on the conductor with silicone rubber, and cooling and curing at a cooling rate of 40 to 80°C / min to obtain a weather-resistant insulating conductor; S7: using a braiding device to braid tinned copper wire onto the outside of the weather-resistant insulating conductor, completing the braiding of the shielding layer, and obtaining a shielded cable; S8: using a braiding device to braid the tinned copper wire onto the outside of the weather-resistant insulating conductor, completing the braiding of the shielding layer, and obtaining a shielded cable; The traction device passes the shielded cable into the extruder, dynamically adjusts the extrusion temperature of the extruder within the range of 60 to 70°C, and the pressure within the range of 50 to 160 bar, and forms a uniform anti-corrosion layer on the conductor with the soft polyvinyl chloride through high temperature and high pressure, and uniformly cools and solidifies at a cooling rate of 35 to 80°C / min to obtain an anti-corrosion cable; S9: Using the traction device to pass the anti-corrosion cable into the extruder, dynamically adjusts the extrusion temperature of the extruder within the range of 150 to 200°C, and the pressure within the range of 60 to 190 bar, and forms a uniform wear-resistant layer on the conductor with the low-smoke halogen-free polyolefin through high temperature and high pressure, and uniformly cools and solidifies at a cooling rate of 50 to 90°C / min to obtain a multi-core cable;S10: Perform appearance inspection, dimension inspection, and withstand voltage test on the multi-core cable to obtain a finished cable. ;

[0010] Furthermore, the traction device is a single-rail cable traction machine; and the braiding device is a copper wire braiding machine.

[0011] Furthermore, the diameter of the main core is greater than the diameter of the auxiliary core, and the speed ratio of the main core and the auxiliary core passing through the cable core filling paste is 2:1.

[0012] The beneficial effects of the present invention are as follows: the present invention adopts a multi-core cable, avoids the skin effect of the cable, reduces the power consumption of the cable, and at the same time, by infiltrating the cable core filling paste on the outside of the main core and the auxiliary core and infiltrating the cable core filling paste on the outside after the main core and the auxiliary core are twisted into one, the inside and outside of the combined cable core are filled with the cable core filling paste, thereby ensuring that the cavity at the contact part of the main core and the auxiliary core is filled, effectively reducing the internal gap of the combined cable core, ensuring the structural strength and filling density of the combined cable core, improving the filling and fixing effect of the filling layer, thereby improving the mechanical strength and environmental adaptability of the cable, and ensuring the stability of the use of the multi-core cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of a multi-strand twisted multi-core cable of the present invention.

[0014] The components in the attached drawings are marked as follows: 1. main core; 2. auxiliary core; 3. filling layer; 4. insulation layer; 5. weather-resistant layer; 6. shielding layer; 7. anti-corrosion layer; 8. wear-resistant layer. DETAILED DESCRIPTION

[0015] The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention.

[0016] See also Figure 1 The present invention provides a multi-strand twisted multi-core cable, comprising a main core 1 and a secondary core 2 wound around the main core 1, the main core 1 is made of aluminum alloy, the secondary core 2 is made of aluminum alloy, a filling layer 3 is filled between the main core 1 and the secondary core 2, the filling layer 3 is a cable core filling paste, the cable core filling paste includes but is not limited to silicone rubber, epoxy resin, polyurethane, etc. An insulating layer 4 is wound around the secondary core 2, a weather-resistant layer 5 is provided outside the insulating layer 4, a shielding layer 6 is provided outside the weather-resistant layer 5, an anti-corrosion layer 7 is provided outside the shielding layer 6, an anti-corrosion layer 7 is provided outside the anti-corrosion layer 7, and an anti-wear layer 8 is provided outside the anti-corrosion layer 7.

[0017] Specifically, the main core 1 is provided with one strand as the central strand, and seven auxiliary cores 2 are twisted outside the main core 1. The main core 1 and the auxiliary core 2 are combined into a "1+6" twisted structure, and a combined cable core is produced by using a back-twisting cage twisting device. After the twisting is completed, the combined cable core is soaked in the cable core filling paste, and then taken out and cured to obtain a filling layer 3. The combined cable core is then passed through an extruder, and an insulating layer 4 is extruded onto the outside of the filling layer 3 to ensure roundness, completing the preliminary processing. The insulating layer 4 is made of cross-linked polyethylene.

[0018] In this embodiment, cavities are formed between the main core 1 and the auxiliary core 2, and between the auxiliary core 2 and the insulating layer 4. During processing, the main core 1 and the auxiliary core 2 are first immersed in the cable core filling paste before twisting, and then taken out for twisting, so as to ensure that the cavity at the contact part of the main core 1 and the auxiliary core 2 is filled. The present invention fills the cavity with the cable core filling paste through two infiltrations, thereby ensuring the structural strength and filling density of the combined cable core.

[0019] The weather-resistant layer 5 is sprayed on the outside of the insulating layer 4 by coating. The material of the weather-resistant layer 5 includes but is not limited to silicone rubber. The shielding layer 6 is made of tinned copper to protect the circuit from interference from external electromagnetic waves. The anti-corrosion layer 7 is made of soft polyvinyl chloride, and the wear-resistant layer 8 is extruded from low-smoke halogen-free polyolefin. Preferably, the weather-resistant layer 5, the anti-corrosion layer 7 and the wear-resistant layer 8 are coaxially arranged.

[0020] When in use, the filling layer 3 is used to fix and fill the combined cable core, thereby improving the mechanical strength and environmental adaptability of the cable and ensuring the normal operation of the line. At the same time, the multi-core cable core effectively avoids the skin effect of the cable and reduces the power consumption of the cable. The present invention also uses the weather-resistant layer 5, the anti-corrosion layer 7 and the wear-resistant layer 8 to cooperate, so that the present invention has multiple anti-corrosion effects, while ensuring its wear resistance and bending performance, and improving the use effect. The wear-resistant layer 8 is a low-smoke halogen-free polyolefin protective sleeve to prevent the combustion from producing harmful gases and improve the environmental protection level of the present invention.

[0021] The present invention also provides a manufacturing process for a multi-strand twisted multi-core cable applicable to the multi-strand twisted multi-core cable, comprising:

[0022] S1: The conductive material is processed into a desired shape and size by stretching, straightening, cutting and other processes to obtain a main core 1 and a sub-core 2.

[0023] S2: The cable core filling paste is heated to 120-220° C. to melt it into a molten state, and a traction device is used to pull the main core 1 and the auxiliary core 2 respectively to be immersed in the cable core filling paste. The main core 1 passes through the cable core filling paste at a speed of 10-15 m / min, and the auxiliary core 2 passes through the cable core filling paste at a speed of 10-15 m / min, thereby completing the preliminary coating of the main core 1 and the auxiliary core 2.

[0024] S3: Before the cable core filling paste on the surface of the main core 1 and the auxiliary core 2 solidifies, the main core 1 and the auxiliary core 2 are twisted into one by using a traction device and a back-twisting cage twisting device, wherein the main core 1 serves as the central strand and the auxiliary core 2 is wound around the main core 1 to form a "1+6" twisted structure to obtain a combined cable core.

[0025] S4: The cable core filling paste is heated to 140-280°C, and the combined cable core is pulled by a pulling device to be immersed in the cable core filling paste. The combined cable core passes through the cable core filling paste at a speed of 10-15 m / min, so that the inside and outside of the combined cable core are filled with the cable core filling paste. The combined cable core is uniformly cooled and solidified at a cooling rate of 10-20°C / min to complete the coating of the filling layer 3 and obtain the conductor.

[0026] S5: The conductor is introduced into an extruder by means of a traction device, and the extrusion temperature of the extruder is dynamically adjusted within the range of 80 to 90° C. and the pressure is between 40 and 120 bar. The cross-linked polyethylene is made to form a uniform insulating layer 4 on the conductor by means of high temperature and high pressure, and the conductor is uniformly cooled and solidified at a cooling rate of 30 to 60° C. / min to obtain an insulated conductor.

[0027] S6: Use a traction device to pass the insulated conductor into an extruder, dynamically adjust the extrusion temperature of the extruder within the range of 180 to 210° C., and the pressure between 60 and 180 bar, so that the silicone rubber forms a uniform weather-resistant layer 5 on the conductor through high temperature and high pressure, and cools and solidifies at a uniform rate of 40 to 80° C. / min to obtain a weather-resistant insulated conductor.

[0028] S7: Using a braiding device, braid the tinned copper wire onto the outside of the weather-resistant insulated conductor to complete the braiding of the shielding layer 6 to obtain a shielded cable.

[0029] S8: Use a traction device to pass the shielded cable into an extruder, dynamically adjust the extrusion temperature of the extruder within the range of 60 to 70°C, and the pressure between 50 and 160 bar, so that the soft polyvinyl chloride forms a uniform anti-corrosion layer 7 on the conductor through high temperature and high pressure, and cools and solidifies at a uniform rate of 35 to 80°C / min to obtain an anti-corrosion cable.

[0030] S9: Use a traction device to pass the anti-corrosion cable into an extruder, dynamically adjust the extrusion temperature of the extruder within the range of 150 to 200°C, and the pressure between 60 and 190 bar, and form a uniform wear-resistant layer 8 of low-smoke halogen-free polyolefin on the conductor through high temperature and high pressure, and cool and solidify at a uniform speed of 50 to 90°C / min to obtain a multi-core cable.

[0031] S10: Perform appearance inspection, dimension inspection, and pressure resistance test on the multi-core cable to ensure that the product quality meets the requirements and obtain the finished cable. After passing the inspection, the multi-core cable is packaged for transportation and sale.

[0032] In this embodiment, the traction device includes but is not limited to a single-rail cable traction machine, which is used to achieve traction and movement of the cable; the weaving device includes but is not limited to a copper wire weaving machine, which is used to ensure the uniformity of the weaving of tinned copper wire and improve the shielding effect of the cable; the extruder is a common cable extruder on the market and is provided with multiple ones, which can wrap the cable differently according to different extrusion materials to ensure processing efficiency.

[0033] In this embodiment, the diameter of the main core 1 is greater than the diameter of the auxiliary core 2, and the speed ratio of the main core 1 and the auxiliary core 2 passing through the cable core filling paste is 2:1. The present invention adopts cable cores of different diameters, which effectively improves the mechanical strength, improves the bending performance, improves the stability and reliability, reduces the size and weight of the cable, and meets specific specifications and standards. A core formed by twisting multiple single wires in a certain direction and twisting rules has good stability because the position of each single wire in the stranded wire is alternately in the elongation zone at the upper part of the stranded wire and the compression zone at the lower part of the stranded wire. When the stranded wire is bent, it will not deform. At the same time, the core formed by twisting multiple single wires can disperse the unevenness of the material or the defects generated in the twisting, thereby improving the reliability of the conductive core.

[0034] The present invention adopts a multi-core cable, avoids the skin effect of the cable, reduces the power consumption of the cable, and at the same time, by infiltrating the cable core filling paste on the outside of the main core 1 and the auxiliary core 2 and infiltrating the cable core filling paste on the outside after the main core 1 and the auxiliary core 2 are twisted into one, the inside and outside of the combined cable core are filled with the cable core filling paste, thereby ensuring that the cavity at the contact part of the main core 1 and the auxiliary core 2 is filled, effectively reducing the internal gap of the combined cable core, ensuring the structural strength and filling density of the combined cable core, improving the filling and fixing effect of the filling layer 3, thereby improving the mechanical strength and environmental adaptability of the cable, and ensuring the stability of the use of the multi-core cable.

[0035] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A multi-core cable with multiple strands, characterized in that: The invention comprises a main core (1) and a secondary core (2) wound around the main core (1), a filling layer (3) being filled between the main core (1) and the secondary core (2), the main core (1) being provided with one strand as a central strand, seven secondary cores (2) being twisted around the outside of the main core (1), an insulating layer (4) being wound around the outside of the secondary core (2), a weather-resistant layer (5) being provided around the outside of the insulating layer (4), a shielding layer (6) being provided around the outside of the weather-resistant layer (5), an anti-corrosion layer (7) being provided around the outside of the shielding layer (6), and an abrasion-resistant layer (8) being provided around the outside of the anti-corrosion layer (7).

2. The multi-strand twisted multi-core cable according to claim 1, characterized in that: The filling layer (3) is a cable core filling paste, and cavities are formed between the main core (1) and the auxiliary core (2) and between the auxiliary core (2) and the insulating layer (4), and the cable core filling paste is filled into the cavities.

3. The multi-strand twisted multi-core cable according to claim 1, characterized in that: The weather-resistant layer (5) is sprayed on the outside of the insulating layer (4), and the material of the weather-resistant layer (5) includes silicone rubber. The shielding layer (6) is made of tinned copper braid; the anti-corrosion layer (7) is made of soft polyvinyl chloride, and the wear-resistant layer (8) is made of low-smoke halogen-free polyolefin extrusion.

4. A manufacturing process of a multi-strand twisted multi-core cable, applicable to the multi-strand twisted multi-core cable according to any one of claims 1 to 3, comprising: S1: Processing the conductive material into a desired shape and size by stretching, straightening, cutting, etc. to obtain a main core (1) and a secondary core (2); S2: heating the cable core filling paste to 120-220° C. to melt it into a molten state, using a pulling device to pull the main core (1) and the auxiliary core (2) into the cable core filling paste, respectively, so that the main core (1) passes through the cable core filling paste at a speed of 10-15 m / min, and the auxiliary core (2) passes through the cable core filling paste at a speed of 10-15 m / min, thereby completing the preliminary coating of the main core (1) and the auxiliary core (2); S3: before the cable core filling paste on the surface of the main core (1) and the auxiliary core (2) is solidified, the main core (1) and the auxiliary core (2) are twisted together by using a traction device and a back-twisting cage twisting device, wherein the main core (1) serves as the central strand and the auxiliary core (2) is wound around the main core (1) to form a "1+6" twisted structure, thereby obtaining a combined cable core; S4: heating the cable core filling paste to 140-280° C., using a pulling device to pull the combined cable core to be immersed in the cable core filling paste, the combined cable core passing through the cable core filling paste at a speed of 10-15 m / min, so that the combined cable core is filled with the cable core filling paste inside and outside, and cooling and solidifying at a cooling speed of 10-20° C. / min, completing the coating of the filling layer (3), and obtaining a conductor; S5: using a traction device to pass the conductor into an extruder, dynamically adjusting the extrusion temperature of the extruder within the range of 80 to 90° C. and the pressure within the range of 40 to 120 bar, so that the cross-linked polyethylene forms a uniform insulating layer (4) on the conductor through high temperature and high pressure, and uniformly cooling and solidifying at a cooling rate of 30 to 60° C. / min to obtain an insulated conductor; S6: using a traction device to pass the insulated conductor into an extruder, dynamically adjusting the extrusion temperature of the extruder within the range of 180 to 210° C. and the pressure within the range of 60 to 180 bar, so that the silicone rubber forms a uniform weather-resistant layer (5) on the conductor through high temperature and high pressure, and uniformly cools and solidifies at a cooling rate of 40 to 80° C. / min to obtain a weather-resistant insulated conductor; S7: Using a braiding device to braid the tinned copper wire onto the outside of the weather-resistant insulated conductor, completing the braiding of the shielding layer (6) to obtain a shielded cable; S8: using a traction device to pass the shielded cable into an extruder, dynamically adjusting the extrusion temperature of the extruder within the range of 60 to 70° C. and the pressure within the range of 50 to 160 bar, so that the soft polyvinyl chloride forms a uniform anticorrosion layer (5) on the conductor through high temperature and high pressure, and uniformly cools and solidifies at a cooling rate of 35 to 80° C. / min to obtain an anticorrosion cable; S9: using a traction device to pass the anti-corrosion cable into an extruder, dynamically adjusting the extrusion temperature of the extruder within the range of 150 to 200° C. and the pressure within the range of 60 to 190 bar, so that the low-smoke halogen-free polyolefin forms a uniform wear-resistant layer (8) on the conductor through high temperature and high pressure, and uniformly cooling and solidifying at a cooling rate of 50 to 90° C. / min to obtain a multi-core cable; S10: Performing appearance inspection, dimension inspection, and voltage resistance test on the multi-core cable to obtain a finished cable.

5. The manufacturing process of the multi-strand twisted multi-core cable according to claim 4, characterized in that: The traction device is a single-rail cable traction machine; the braiding device is a copper wire braiding machine.

6. The manufacturing process of the multi-strand twisted multi-core cable according to claim 5, characterized in that: The diameter of the main core (1) is greater than the diameter of the auxiliary core (2), and the speed ratio of the main core (1) and the auxiliary core (2) passing through the cable core filling paste is 2:1.

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