Shielding type multi-core cable

Abstract

The utility model relates to the technical field of cables, and particularly discloses a shielding type multi-core cable, which comprises a first wire core and a plurality of second wire cores circularly arrayed on the periphery of the first wire core along the radial direction, each of the first wire core and the second wire core comprises a conductor, an insulating layer, a fireproof layer and a shielding layer which are sequentially coated from inside to outside along the radial direction; the second wire core is integrally coated with a sheath layer; the cable provided by the utility model has good shielding performance. The flexibility of the cable is integrally improved, the mechanical performance of the multi-core cable is improved, the protection performance of the conductors is better, the insulation performance between the wire cores is better, and the fireproof performance and the safety protection performance are better.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a shielded multi-core cable. Background Art

[0002] Multi-core cables typically refer to cables with more than one insulated core. Multi-core cables not only reduce line losses but can also transmit multiple signals simultaneously or separately, making them suitable for transmitting multiple signals or power sources. They offer flexibility, reliability, and high efficiency. There are two types of multi-core cables: shielded and unshielded. Shielded multi-core cables are cables that have a shielding layer added to the multi-core cable. This shielding layer protects against external interference and electromagnetic wave loss during signal transmission.

[0003] Due to the varying environments and transmission requirements for multi-core cables, the requirements for shielding performance, transmission functionality, and cable mechanical properties also vary. For example, cables with more and thinner conductors generally have better mechanical properties in terms of flexibility, but a larger number of conductors may reduce transmission performance. Conventional shielded multi-core cables primarily consist of multiple insulated cores and an outer sheath. Each insulated core is insulated with a separate insulating material, and different cores can transmit different signals or power.

[0004] The number of conductors, shielding layers, insulation layers and other structures of multi-core cables are different, as are the manufacturing processes. This will affect the overall shielding performance and fire resistance of the cable. How to manufacture an internal cable structure that matches the number of conductors to improve the overall performance of the cable is a technical problem to be solved in this field. The functional principle of the shielding layer is that the interference current can be effectively conducted to the earth only when the shielding layer is completely and well grounded. However, in the prior art, due to the limitations of the structural position of the conductors and shielding layers of multi-core cables, the shielding layer is discontinuous, which destroys the integrity of the cable and makes the shielding layer a source of interference. If the shielding layer is damaged in a certain part of the cable, it will inevitably affect the transmission function of all the cores, resulting in low shielding performance or easy loss of shielding effect. Utility Model Content

[0005] The purpose of the present utility model is to provide a shielded multi-core cable, which is designed to address the problem of low shielding performance in the prior art due to the poor matching degree between the connection structure of the shielding layer and the multiple cores. The utility model comprises: a first core and a plurality of second cores arranged in a radial circular array around the first core; the first core and each of the second cores comprise: a conductor, an insulating layer, a fire-resistant layer and a shielding layer wrapped in sequence from the inside to the outside along the radial direction; the outside of the second core is entirely covered with a sheath layer.

[0006] The solution of the utility model is to arrange multiple cores as second cores in a radial circular array around the periphery of the first core, and to arrange a shielding layer on the outside of the first core and each second core, so that the shielding layer acts on each core, so that each core has a corresponding shielding layer. Compared with the traditional shielding layer with a single setting or the shielding layer setting without considering the arrangement of the cores, even if the shielding layer of one core is damaged, it will not affect the shielding function of the other cores, nor will it interfere with the electrical signal transmission of the other cores, thereby improving the shielding performance; on the other hand, according to the actual conductivity In accordance with the energy requirements, by setting the appropriate first core diameter and second core diameter, the appropriate number of cores can be set, and the shielding function of each core can be matched, thereby improving the flexibility of the cable as a whole and improving the mechanical properties of the multi-core cable; and, by wrapping the shielding layer on the outside of the insulation layer and fire-resistant layer of the first core or each second core, the insulation layer and the fire-resistant layer can protect each second core or the first core, thereby improving the protection performance of the conductor of the first core or the second core, and the insulation performance between the cores is better, further improving the fire resistance and safety protection performance of the cable.

[0007] Preferably, in the shielded multi-core cable described in the present invention, the first core is formed by regular twisting of at least seven Class A conductors; the Class A conductors are copper or aluminum; the first core is used for power connection; the second core is formed by twisting at least forty-nine Class B conductors; the Class B conductors are copper; the second core is used for non-power connection.

[0008] As a preferred solution of the present invention, the first core is set to be at least seven copper or aluminum wires twisted in a regular manner and then used for power connection. Since the first core is located in the center of the cable, the flexibility requirement is lower than that of the second core with a larger outer diameter, while meeting the conductivity and resistivity requirements of the power connection; the second core is arranged in a radial circular array on the periphery of the first core and is a twisted copper wire, which has better flexibility and is used for non-power connection, so that different cores have different structures according to functional requirements, so that the use function of the cable is structurally divided and specific, thereby improving the conductivity and further improving the mechanical properties of the cable.

[0009] Preferably, in the shielded multi-core cable described in the present invention, the first-class conductors include seven, and the diameter of the first-class conductors is 1.7mm to 1.8mm; the second-class conductors include forty-nine, and the diameter of the second-class conductors is 0.2mm to 0.3mm.

[0010] As a preferred solution of the present invention, by setting the number and diameter of the first type of conductors to meet the structural requirements of the first wire core, and then setting the diameter and number of the second type of conductors, the bending performance and flexibility of the cable can be further optimized, thereby improving the durability and applicability of the cable.

[0011] Preferably, in the shielded multi-core cable described in the present invention, the shielding layer is woven from multiple Class III conductors; the braiding density is ≥70%; the Class III conductors are copper wires or tinned copper wires, and the diameters of the Class III conductors are 0.08mm to 0.3mm.

[0012] As a preferred solution of the present invention, by setting the shielding layer to be woven from copper wire or tinned copper wire, and the braiding density reaches 70%, and the diameter of the copper wire or tinned copper wire is selected to be 0.08mm~0.3mm, the braiding density can be made suitable for the diameter of the three types of conductors, thereby further enhancing the shielding performance of the shielding layer, while reducing the probability of bending breakage of the shielding layer, and improving the durability of the cable.

[0013] Preferably, in the shielded multi-core cable described in the present invention, the material of the insulation layer is thermoplastic polyurethane or thermoplastic vulcanized rubber; the thickness of the insulation layer of the first core is 1.0mm~1.2mm; the thickness of the insulation layer of the second core is 0.7mm~1.0mm.

[0014] As a preferred embodiment of the present invention, by setting the material of the insulating layer to thermoplastic polyurethane or thermoplastic vulcanized rubber, it can have a temperature resistance in the range of -40°C to 80°C, and has good flame retardancy, elasticity and temperature resistance; on the other hand, by setting the difference in the thickness of the insulation layer of Class I wire cores and Class II wire cores, it can save the amount of insulating material on the basis of meeting the insulation requirements, reduce the use of consumables, reduce costs and improve production efficiency.

[0015] Preferably, in the shielded multi-core cable described in the present invention, the fire-resistant layer includes three layers of mica tape wrapped around the outside of the insulating layer; the thickness of the mica tape is 0.1mm~0.3mm, the width of the mica tape is 20mm~80mm; the overlap rate of the mica tape is 75%.

[0016] As a preferred solution of the present invention, by setting the fire-resistant layer to three layers of mica tape with a thickness of 0.1mm to 0.3mm and a width of 20mm to 80mm, and with a mica tape overlap rate of 75%, good fire resistance is achieved. In the event of a fire, the internal structure of the cable is protected from damage, so that the cable can work normally in extreme environments, further improving the performance of the cable.

[0017] Preferably, in the shielded multi-core cable described in the present invention, the material used for the sheath layer is polyolefin or polyvinyl chloride; the material is coated on the outside of the entire second core through an extrusion process and formed.

[0018] As a preferred solution of the present invention, the sheath layer is provided with a material of polyolefin or polyvinyl chloride, which has good corrosion resistance and aging resistance, and the material is coated on the outside of the second core as a whole and formed through an extrusion process, thereby further reducing the possibility of the sheath layer being torn and damaged, thereby improving the protection performance of the cable interior and enhancing the durability of the cable.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. Compared with the traditional single shielding layer setting or the shielding layer setting without considering the core arrangement, even if the shielding layer of one core is damaged, it will not affect the shielding function of other cores, nor will it interfere with the electrical signal transmission of other cores, thereby improving the shielding performance;

[0021] 2. According to the actual requirements of conductivity, by setting the appropriate first core diameter and second core diameter, the number of cores can be adapted to the shielding function of each core, thereby improving the overall flexibility of the cable and the mechanical properties of the multi-core cable;

[0022] 3. By wrapping the shielding layer around the outside of the insulation layer and fire-resistant layer of the first core or each second core, the insulation layer and fire-resistant layer can protect each second core or the first core, thereby providing better protection for the conductor of the first core or the second core, and better insulation between the cores, further improving the fire resistance and safety protection performance of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional schematic diagram of the multi-core cable of the present utility model;

[0024] Figure 2 This is a schematic cross-sectional view of the three-dimensional structure of the second wire core of the present invention;

[0025] Figure 3 It is a cross-sectional schematic diagram of the first wire core or the second wire core of the present invention;

[0026] Icon: 1. First wire core; 11. Conductor; 12. Insulation layer; 13. Fire-resistant layer; 14. Shielding layer; 2. Second wire core; 3. Sheath layer. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the accompanying drawings.

[0028] Example 1:

[0029] refer to Figures 1 to 3 As shown, the utility model provides a shielded multi-core cable, comprising: a first wire core 11 and a plurality of second wire cores 2 arranged in a radial circular array around the first wire core 1; the first wire core 1 and each of the second wire cores 2 comprise: a conductor 11, an insulating layer 12, a fire-resistant layer 13 and a shielding layer 14 wrapped in sequence from the inside to the outside along the radial direction; the outside of the second wire core 2 is entirely covered with a sheath layer 3.

[0030] It should be noted that the "whole" in the statement that the outer portion of the second core 2 is entirely covered with the sheath layer 3 is understood to be relative to the outer portion of each second core 2. After the second core 2 is covered with the outer portion of the first core 1, the sheath layer 3 is provided on the outer wall of the side away from the first core 1. Figure 1 As shown, it can be understood clearly.

[0031] In this embodiment, Figure 1 As shown, the first core 1 is located in the center of the cable, and multiple second cores 2 are arranged in a radial circular array around the first core 1; it should be noted that since the first core 1 and each second core 2 include a conductor 11, an insulating layer 12, a fire-resistant layer 13 and a shielding layer 14, reference can be made to Figure 1 It is understood that the first core 1 and the second core 2 both contain a conductor 11, an insulating layer 12, a fire-resistant layer 13 and a shielding layer 14, wherein the specific structures of the conductor 11, the insulating layer 12, the fire-resistant layer 13 and the shielding layer 14 are as follows: Figure 1 No specific restrictions or demonstration are made in the text, but the second core 2 and the first core 1 are located in different specific positions inside the cable, so it can be understood that the first core 1 and the second core 2 are clearly described and distinguished, without specific numerical interpretation. Both Class I conductors and Class II conductors belong to the conductor 11 described in the present invention.

[0032] Specifically, such as Figure 3 As shown, the first core 1 is formed by twisting at least seven Class A conductors in a regular manner; the Class A conductors are copper or aluminum; the first core 1 is used for power connection; the second core 2 is formed by twisting at least forty-nine Class B conductors; the Class B conductors are copper; the second core 2 is used for non-power connection.

[0033] It should be noted that the terms "regular twisting" and "informal twisting" are technical terms used in this field and are not to be taken literally. Specifically, the first conductor 1 may be produced by drawing seven copper or aluminum conductors 11 into a single wire with a diameter ≤ 0.5 mm, for example, a single wire with a diameter of 1.35 mm. After annealing and softening, at least seven copper or aluminum wires are bundled and twisted into strands using a doubling machine, depending on the cross-sectional area of the first core 1 required for the product. These strands are then twisted in a regular layered pattern of 1+6+12+18+... on a cable stranding and compacting device, thereby producing the first core 1.

[0034] More specifically, the Class I conductors include seven, and the diameter of the Class I conductors is 1.7mm to 1.8mm; the Class II conductors include forty-nine, and the diameter of the Class II conductors is 0.2mm to 0.3mm. The manufacturing process of the second core 2 can be made by twisting forty-nine copper wires with a single wire diameter of 0.25mm. In the informal process, there is no need to layer the second core 2 or twist it in a fixed number. It should be noted that the Class I and Class II conductors are only defined for clear description and are not explained in specific categories or standards. For example, the Class I conductor corresponds to the first core 1, and the Class II conductor corresponds to the second core 2. It should also be noted that Figure 1 To show the schematic diagram of the specific structure, Figure 1 The specific number of Class I or Class II conductors is not shown. The number can be increased or decreased according to actual conditions using the usual placement method.

[0035] Specifically, in this embodiment, the shielding layer 14 is woven from multiple Class III conductors 11; the braiding density is ≥70%; the Class III conductors 11 are copper wires or tinned copper wires, and the diameter of the Class III conductors 11 is 0.08mm to 0.3mm. It should be noted that braiding is understood to be a commonly used braiding process for the shielding layer 14, which can braid copper wires or tinned copper wires such as the Class III conductors 11 into the shielding layer 14; specifically, according to the outer diameter design requirements of each second core 2 or first core 1, copper wires or tinned copper wires with a single wire diameter of 0.08 to 0.3mm are selected, and are wired into strands, passed through a high-speed braiding machine and at an appropriate pitch, and evenly woven on the outside of the fire-resistant layer 13 of each first core 1 or second core 2; by setting the parameters of the braiding machine, a braiding density ≥70% can be achieved; when setting the parameters of the braiding machine, the braiding density formula can be referred to, as shown in calculation formulas 1 and 2.

[0036] Calculation formula 1:

[0037] In the calculation formula shown in the first paragraph, K fis the filling factor, D is the average outer diameter of the braided layer; W is the round wire braiding item, W=Ndw, where dw is the diameter of the braided wire, L is the braiding pitch, n is the total number of spindles, and N is the number of single wires in each spindle.

[0038] Calculation formula 2: weaving density = (2K f -K f 2 )×100%;

[0039] Specifically, in this embodiment, the insulating layer 12 is made of thermoplastic polyurethane or thermoplastic vulcanized rubber; the thickness of the insulating layer 12 of the first core 1 is 1.0 mm to 1.2 mm; the thickness of the insulating layer 12 of the second core 2 is 0.7 mm to 1.0 mm. For example, the manufacturing process of the insulating layer 12 can be as follows: the flame-retardant elastomer material thermoplastic polyurethane or thermoplastic vulcanized rubber is passed through a plastic extruder and fully plasticized within a processing temperature range of 170°C to 230°C; then, it is evenly coated on the outer surface of the twisted Class I or Class II conductor using a dedicated mold; the extruded thickness of the insulating layer 12 of the first core 1 is 1.0 mm, and the extruded thickness of the second core 2 is 0.8 mm. After water cooling and air cooling, the insulating layer 12 is formed.

[0040] Specifically, in this embodiment, the fire-resistant layer 13 comprises three layers of mica tape wrapped around the outside of the insulating layer 12; the mica tape has a thickness of 0.1 mm to 0.3 mm and a width of 20 mm to 80 mm; and the mica tape has an overlap ratio of 75%. It should be noted that the overlap ratio is a technical term in the cable field and should not be interpreted literally. The wrapping process is a conventional mica tape wrapping process. The wrapping angle of the mica tape is controlled by setting parameters on conventional wrapping equipment to achieve an overlap ratio of 75%. More specifically, the mica tape is a fire-resistant material and is wrapped around the outside of the insulating layer 12 of the first core 1 or the second core 2, respectively. The mica tape preferably has a thickness of 0.3 mm and a width of 10 mm. The mica tape is wrapped in three layers, with an overlap ratio of 50% for each layer, resulting in an overlap ratio of 85%. The mica tape has excellent fire resistance and effectively protects the internal structure of the cable in the event of a fire, ensuring normal power transmission.

[0041] Specifically, the jacket layer 3 of the present invention is made of polyolefin or polyvinyl chloride; this material is applied to the entire exterior of the second core 2 through an extrusion process to form the jacket. For example, a low-smoke, halogen-free, flame-retardant polyolefin or low-smoke, halogen-free, flame-retardant polyvinyl chloride material is fully plasticized in a plastic extruder within a processing temperature range of 160°C-200°C, then uniformly applied to the entire exterior of the second core 2, which has been fabricated with the shielding layer 14, through a dedicated mold. The jacket layer 3 is then formed after being water-cooled and air-cooled.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shielded multi-core cable, characterized in that: include: A first wire core (1) and a plurality of second wire cores (2) arranged in a radial circular array around the first wire core (1); the first wire core (1) and each of the second wire cores (2) comprise: a conductor (11), an insulating layer (12), a fire-resistant layer (13), and a shielding layer (14) wrapped in sequence from the inside to the outside in the radial direction; the outside of the second wire core (2) is entirely covered with a sheath layer (3).

2. The shielded multi-core cable according to claim 1, wherein: The first core (1) is formed by twisting at least seven Class I conductors in a regular manner; the Class I conductors are copper or aluminum; the first core (1) is used for power connection; the second core (2) is formed by twisting at least forty-nine Class II conductors; the Class II conductors are copper; the second core (2) is used for non-power connection.

3. The shielded multi-core cable according to claim 2, characterized in that: The first type of conductors includes seven conductors, and the diameter of the first type of conductors is 1.7mm to 1.8mm; the second type of conductors includes forty-nine conductors, and the diameter of the second type of conductors is 0.2mm to 0.3mm.

4. The shielded multi-core cable according to claim 1, wherein: The shielding layer (14) is woven from a plurality of three-type conductors (11); the braiding density is ≥70%; the three-type conductors (11) are copper wires or tinned copper wires, and the diameter of the three-type conductors (11) is 0.08 mm to 0.3 mm.

5. The shielded multi-core cable according to any one of claims 1 to 4, characterized in that: The material of the insulating layer (12) is thermoplastic polyurethane or thermoplastic vulcanized rubber; the thickness of the insulating layer (12) of the first wire core (1) is 1.0 mm to 1.2 mm; the thickness of the insulating layer (12) of the second wire core (2) is 0.7 mm to 1.0 mm.

6. The shielded multi-core cable according to any one of claims 1 to 4, characterized in that: The fire-resistant layer (13) comprises three layers of mica tape wrapped around the outside of the insulating layer (12); the thickness of the mica tape is 0.1 mm to 0.3 mm, the width of the mica tape is 20 mm to 80 mm; and the overlap rate of the mica tape is 75%.

7. The shielded multi-core cable according to any one of claims 1 to 4, characterized in that: The material used for the sheath layer (3) is polyolefin or polyvinyl chloride; the material is coated on the entire exterior of the second wire core (2) through an extrusion process and formed.

Images