Cable

Abstract

The utility model discloses a cable, which belongs to the field of cables and comprises a core wire, a middle coating layer, a first shielding layer, a second shielding layer and a ground wire, the middle coating layer is coated outside the core wire, the first shielding layer is coated outside the middle coating layer, the second shielding layer is coated outside the first shielding layer, and the ground wire is positioned between the middle coating layer and the first shielding layer. According to the cable provided by the utility model, through the combined action of multiple layers of structures, the middle coating layer, the first shielding layer and the second shielding layer can be dispersed to each layer when bearing external bending stress, so that the stress concentration of the core wire is reduced, the probability of deformation of the core wire due to repeated bending is reduced, the characteristic impedance stability is maintained, the signal transmission is ensured, and the data transmission abnormity is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of cables, and in particular relates to a cable. Background Technology

[0002] In today's era of highly integrated and intelligent electronic devices, many devices need to achieve stable signal and power transmission under complex working conditions of dynamic bending. As an indispensable connecting component, the performance of cables directly affects the overall reliability of the equipment.

[0003] However, currently widely used traditional cables exhibit numerous significant technical bottlenecks under dynamic bending scenarios. When subjected to repeated bending, conventional cable structures are prone to stress concentration areas at the bending points, causing the conductor to deform under repeated stress. This deformation and stress concentration lead to significant fluctuations in the cable's characteristic impedance, severely deteriorating return loss and ultimately resulting in a substantial reduction in signal transmission quality. Frequent packet loss and bit errors occur during data transmission, severely hindering the efficient operation of equipment in dynamic working environments.

[0004] Regarding shielding, while single-layer shielded cables can resist external electromagnetic interference to a certain extent, the integrity of the shielding layer is easily compromised when subjected to mechanical stress. With each bend, its shielding effectiveness decreases sharply. In today's complex electromagnetic environment, especially with broadband interference sources, single-layer shielded cables are no longer sufficient to protect internally transmitted signals. They are highly susceptible to coupling interference from stray electromagnetic signals, leading to severe signal distortion or even complete transmission failure.

[0005] Some cables employing a double-shielded design, intended to enhance shielding effectiveness, suffer from a lack of effective bending-resistant support structures. During dynamic bending, the two shielding layers, as well as the shielding layer and other internal cable structures, struggle to deform in tandem. This leads to premature delamination and breakage of the shielding layer under repeated bending, significantly shortening the cable's dynamic bending lifespan. Frequent cable replacements not only increase equipment maintenance costs but also severely limit the widespread adoption and application of such equipment in long-term dynamic applications where cable reliability is paramount.

[0006] It is evident that the performance limitations of existing cable technology in dynamic bending scenarios have become a key factor hindering further development in many fields. There is an urgent need to develop a new cable structure design to effectively overcome problems such as conductor deformation, reduced shielding effectiveness, and insufficient dynamic bending life, so as to meet the stringent requirements of modern electronic equipment and communication systems for high performance and high reliability in complex dynamic working environments. Utility Model Content

[0007] The purpose of this invention is to provide a cable that overcomes at least one of the aforementioned defects in the prior art.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] The present invention provides a cable comprising a core wire, a middle sheath, a first shielding layer, a second shielding layer, and a ground wire. The core wire is covered by the middle sheath, the middle sheath is covered by the first shielding layer, the first shielding layer is covered by the second shielding layer, and the ground wire is located between the middle sheath and the first shielding layer.

[0010] Preferably, the outer wall of the middle layer has a limiting space, and the ground wire is inserted into the limiting space.

[0011] Preferably, the core wire includes at least one conductor and an insulating portion covering the conductor.

[0012] Preferably, it further includes a protective layer, with the second shielding layer covered by the protective layer.

[0013] Preferably, the limiting space extends through the middle quilt layer along its length.

[0014] Preferably, the limiting space is an arc-shaped channel.

[0015] Preferably, the insulating part includes an insulator, which is one insulator and covers all conductors, or there are two or more conductors, the number of insulators is the same as the number of conductors, and each insulator covers one conductor.

[0016] Preferably, the insulating part further includes an insulating layer, and the insulating body is covered with an insulating layer.

[0017] Preferably, the insulator is made of PP, PE, FEP or PFA, and the insulating layer is made of foamed material.

[0018] Preferably, the insulating layer is wrapped around the insulator.

[0019] Preferably, the first shielding layer covers the outer layer of the middle layer in a longitudinal wrapping manner, and the second shielding layer covers the outer layer of the first shielding layer in a wrapping manner.

[0020] Preferably, the material of the inner sheath is PP, PE or FEP, and the inner sheath is extruded and molded to cover the core wire.

[0021] Preferably, both the first shielding layer and the second shielding layer are made of metal.

[0022] Preferably, the first shielding layer is aluminum foil or copper foil, and the second shielding layer is aluminum foil.

[0023] Preferably, the protective layer is a Mylar layer or a flame-retardant PET layer.

[0024] Preferably, there are one or two ground wires. When there is one ground wire, the ground wire is located on either side of the cable center line. When there are two ground wires, the two ground wires are respectively set on both sides of the cable center line.

[0025] The beneficial effects of this utility model are as follows:

[0026] 1. Through the combined action of multiple layers, the middle layer, the first shielding layer, and the second shielding layer can distribute the external bending stress to each layer, reducing the stress concentration on the core wire, lowering the probability of the core wire deforming due to repeated bending, maintaining stable characteristic impedance, ensuring signal transmission, and reducing data transmission anomalies.

[0027] 2. The first and second shielding layers constitute a double layer of protection, which shields electromagnetic interference of different frequency bands and directions respectively. In a broadband interference environment, it effectively blocks external stray electromagnetic signals, reduces the risk of signal distortion, and improves the integrity and accuracy of signal transmission.

[0028] 3. The ground wire located between the middle shielding layer and the first shielding layer can balance the electric field, guide the current induced on the first shielding layer into the ground, avoid the induced current forming a circulating current that interferes with the internal signal, optimize the shielding performance, and enhance the overall shielding effect.

[0029] 4. The middle sheath provides basic structural support for the entire cable. During dynamic bending, it stabilizes the position of the core wires, preventing excessive displacement or deformation due to external forces.

[0030] 5. The middle shielding layer possesses excellent flexibility and elasticity. During dynamic bending, it deforms accordingly with the bending shape of the cable, simultaneously deforming the core wire, the first shielding layer, and the second shielding layer. This ability to deform in tandem ensures that the layers maintain a relatively stable positional relationship, preventing the shielding layer from delaminating or breaking during bending.

[0031] 6. By setting the limiting space, the ground wire is limited, which not only facilitates the covering of the ground wire during the molding process, but also prevents the ground wire from deviating after molding.

[0032] 7. By using the method of covering the ground wire with the first shielding layer, the contact area between the first shielding layer and the ground wire is increased, thereby improving the shielding effect.

[0033] 8. The second shielding layer is aluminum foil. Aluminum foil has excellent heat reflectivity, which can reflect some heat and reduce heat transfer to the other side. In the event of a fire, aluminum foil can protect other materials inside the cable to a certain extent, delaying the time it takes for these materials to reach their ignition point due to heat, thus playing a certain role in flame retardancy and protection. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the main structure of this utility model.

[0035] Figure 2 This is a three-dimensional structural diagram of the present invention.

[0036] Figure 3 This is a schematic diagram of the main structure of the layer in this utility model.

[0037] Figure 4 This is a comparison diagram of the bending impedance deviation between the cable of this utility model and the traditional cable.

[0038] The markings in the attached diagram are: 1-core wire, 2-middle sheath, 3-first shielding layer, 4-second shielding layer, 5-ground wire, 21-limiting space, 11-conductor, 6-protective layer, 12-insulator, 13-insulating layer. Detailed Implementation

[0039] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0040] Contents not described in detail in this specification are existing technologies known to those skilled in the art. In the description of this utility model, it should be understood that terms such as "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this utility model. Furthermore, terms such as "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] like Figures 1 to 3 As shown, the cable provided in this embodiment includes a core wire 1, a middle sheath 2, a first shielding layer 3, a second shielding layer 4, and a ground wire 5. The core wire 1 is covered by the middle sheath 2, the middle sheath 2 is covered by the first shielding layer 3, the first shielding layer 3 is covered by the second shielding layer 4, and the ground wire 5 is located between the middle sheath 2 and the first shielding layer 3.

[0042] Through the combined action of multiple layers, the middle sheath 2, the first shielding layer 3, and the second shielding layer 4 can disperse external bending stress among the layers, reducing stress concentration on the core wire 1, lowering the probability of deformation due to repeated bending, maintaining stable characteristic impedance, ensuring signal transmission, and reducing data transmission anomalies. The first shielding layer 3 and the second shielding layer 4 constitute double-layer protection, shielding against electromagnetic interference of different frequency bands and directions. In broadband interference environments, they effectively block stray electromagnetic signals, reduce the risk of signal distortion, and improve the integrity and accuracy of signal transmission. The ground wire 5, located between the middle sheath 2 and the first shielding layer 3, can balance the electric field and guide the current induced on the first shielding layer 3 into the ground, preventing the induced current from forming a circulating current that interferes with the internal signal, optimizing shielding performance, and enhancing the overall shielding effect. The middle sheath 2 provides basic structural support for the entire cable. During dynamic bending, it can stabilize the position of the core wire 1, preventing excessive displacement or deformation of the core wire 1 due to external forces. Meanwhile, the presence of the middle sheath 2 makes the internal structure of the cable more compact, providing a stable substrate for the first shielding layer 3 and the second shielding layer 4, which helps the layers to better coordinate deformation during bending. The middle sheath 2 is made of FEP, which has excellent flexibility and elasticity. During dynamic bending, it can deform accordingly with the bending shape of the cable, simultaneously deforming the core wire 1, the first shielding layer 3, and the second shielding layer 4. This ability to coordinate deformation allows the layers to maintain a relatively stable positional relationship, preventing delamination or breakage of the shielding layers during bending. For example, when the cable bends to one side, the middle sheath 2 stretches on the outside of the bend and compresses on the inside. This deformation is evenly transmitted to the first shielding layer 3 and the second shielding layer 4, allowing them to deform appropriately without creating excessive stress differences that could lead to delamination. The middle sheath 2 is extruded and molded to cover the core wire 1, allowing the material to melt under high temperature and pressure and evenly coat the surface of the core wire 1. After cooling and solidification, it forms a protective layer 6 that is tightly bonded to the core wire 1. This tightly fitting structure can effectively fix the position of the core wire 1, preventing the core wire 1 from moving or shaking inside the cable, thereby enhancing the overall stability of the cable structure. Especially in dynamic bending scenarios, it can better protect the core wire 1 from external damage.

[0043] The outer wall of the inner lining layer 2 has a limiting space 21, into which the ground wire 5 is inserted. The limiting space 21 is an arc-shaped channel that runs through the inner lining layer 2 along its length. The limiting space 21 serves to limit the ground wire 5, which not only facilitates the covering of the ground wire 5 during the molding process but also prevents the ground wire 5 from deviating after molding.

[0044] In this embodiment, the core wire 1 includes two conductors 11 and an insulator 12 covering the conductors 11. The insulator 12 is covered with an insulating layer 13. By using a first shielding layer 3 to cover the ground wire 5, the contact area between the first shielding layer 3 and the ground wire 5 is increased, thereby improving the shielding effect. In this embodiment, there are two conductors 11, and the insulator 12 is a separate unit, with each insulator 12 covering one conductor 11. In other embodiments, only one conductor 11 may be included. Alternatively, two conductors 11 may be included, but the insulator 12 is a single unit, covering all conductors 11 without an insulating layer 13. The inner foam insulating layer 13 is protected by the middle jacket layer 2, making it less prone to deformation when bent, thus reducing impedance.

[0045] It also includes a protective layer 6, which is an outer covering of the second shielding layer 4. The protective layer 6 is a flame-retardant PET layer with good flame-retardant properties.

[0046] In this embodiment, the insulator 12 is made of PP, and the insulating layer 13 is made of foamed PP. The insulating layer 13 is wrapped around the insulator 12. This allows the insulating layer 13 to be adaptively adjusted according to the bending shape of the cable during wrapping. Compared to some integrally molded insulation methods, the wrapped insulating layer 13 has better flexibility and will not generate excessive stress concentration due to cable bending, thereby avoiding cracking or damage to the insulating layer 13. This is especially important for cables that need to be bent frequently, ensuring the insulation performance and service life of the cable in dynamic operating environments.

[0047] In this embodiment, the first shielding layer 3 is longitudinally wrapped around the middle shielding layer 2, and the second shielding layer 4 is wrapped around the first shielding layer 3. The inner longitudinally wrapped first shielding layer 3 provides a continuous and complete shielding layer, effectively blocking low-frequency interference signals from entering the cable radially. The outer wrapped second shielding layer 4 provides better shielding at high frequencies; its spiral structure better suppresses the radiation and coupling of high-frequency electromagnetic waves, thus achieving good shielding over a wider frequency range and improving the cable's anti-interference capability.

[0048] Furthermore, the outer wrapping of the second shielding layer 4 gives the cable good flame-retardant properties. The following tests use a cable without the second shielding layer 4 as sample 1 and a cable with the second shielding layer as sample 2, respectively, to conduct vertical burning tests on samples 1 and 2.

[0049] Test conditions: ambient temperature 23±5℃, flame application time 15s, flame application interval 15s (flame on the sample can only be applied again after it is completely extinguished), number of burning cycles 5, total flame height 125±10mm, blue inner flame height 40±2mm.

[0050] Experimental methods:

[0051] 1. Start the fire-resistant engine, set the ignition time and ignition interval, and use methane with a purity of over 98% as fuel, then adjust the test flame height;

[0052] 2. Fix the sample on the metal frame inside the flame-retardant machine. Place a layer of pure medical cotton with a thickness of 6 mm in a certain area (not less than 305 mm × 355 mm) under the wire. At the corresponding position on the sample 250 mm above the vertical axis of the blue inner flame tip, attach a piece of kraft paper with a width of 10 mm, a thickness of 0.1 mm, and a weight of 94 g / m² as an indicator flag (around the sample).

[0053] 3. Apply flame to the sample 5 times for 15 seconds each time. The sharp tip of the blue inner flame should just touch the center of the front of the sample. If the flame on the sample goes out, you can continue to apply flame. If the flame on the sample goes out within 15 seconds (including 15 seconds), you can continue to apply flame.

[0054] 4. Record the duration of the flame on the sample after each ignition;

[0055] 5. After the burning is finished, check the condition of the cotton and the indicator flag.

[0056] Judgment criteria:

[0057] If one or more of the following three phenomena occur, the product is judged as unqualified; otherwise, it is judged as qualified.

[0058] 1. The flame duration on the sample exceeds 60 seconds in a single instance;

[0059] 2. The flags are burned or charred by more than 25%;

[0060] 3. The cotton quilt was ignited.

[0061] The test results for sample 1 are shown in Table 1:

[0062] Table 1 Flame retardancy test results for Sample 1

[0063]

[0064] The test results for sample 2 are shown in Table 2:

[0065] Table 2 Flame retardancy test results for sample 2

[0066]

[0067] Flame retardancy tests based on the UL / VW-1 standard were conducted on samples 1 and 2. The results showed that sample 2 had a better flame retardancy effect than sample 1.

[0068] In the flame-retardant test, although the flame-retardant time of Sample 1 was 0 in the last four of the five tests, the first flame-retardant time reached 90 seconds, far exceeding the standard value of 60 seconds; while the flame-retardant time of Sample 2 was within the standard value of 60 seconds in all five tests. In the flag burning area test, Sample 1 ignited, while Sample 2 did not burn. In the cotton ignition test, although neither ignited, considering other test items, Sample 2 performed better in this flame-retardant test, meeting the UL / VW-1 flame-retardant standard requirements and exhibiting superior flame-retardant performance.

[0069] In this embodiment, both the first shielding layer 3 and the second shielding layer 4 are made of metal. The first shielding layer 3 is copper foil, and the second shielding layer 4 is aluminum foil. Aluminum foil has excellent heat reflectivity, reflecting some heat and reducing heat transfer to the other side. In the event of a fire, the aluminum foil can protect other materials inside the cable to some extent, delaying the time it takes for these materials to reach their ignition point, thus providing some flame retardant and protective effects.

[0070] In this embodiment, there are two ground wires 5, which are respectively located on the left and right sides of the cable centerline. In other embodiments, there may be only one ground wire 5, located on either side of the cable centerline.

[0071] like Figure 4 As shown, the bending impedance change of the cable in this embodiment is about 2 ohms, while the traditional method of wrapping the core wire 1 with foamed PP tape results in a bending impedance change of about 10 ohms. The cable of this invention exhibits high signal transmission stability, low transmission loss, wide applicability, strong product reliability, and good electromagnetic compatibility.

[0072] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A cable, characterized in that: It includes a core wire (1), a middle sheath (2), a first shielding layer (3), a second shielding layer (4), and a ground wire (5); The core wire (1) is covered with a middle sheath (2); The middle layer (2) is covered with a first shielding layer (3); The first shielding layer (3) is covered by a second shielding layer (4); The ground wire (5) is located between the middle layer (2) and the first shielding layer (3).

2. The cable according to claim 1, characterized in that: The outer wall of the middle layer (2) has a limiting space (21), and the ground wire (5) is inserted into the limiting space (21).

3. The cable according to claim 1, characterized in that: The core wire (1) includes at least one conductor (11) and an insulating portion covering the conductor (11).

4. The cable according to claim 1, characterized in that: It also includes a protective layer (6); The second shielding layer (4) is covered with a protective layer (6).

5. The cable according to claim 2, characterized in that: The limiting space (21) extends through the middle layer (2) along the length direction of the middle layer (2).

6. The cable according to claim 2, characterized in that: The limiting space (21) is an arc-shaped channel.

7. The cable according to claim 3, characterized in that: The insulating part includes an insulator (12); The insulator (12) is a single unit and encloses all the conductors (11) within it; Alternatively, there may be two or more conductors (11), and the number of insulators (12) may be the same as the number of conductors (11), with each insulator (12) enclosing one conductor (11).

8. The cable according to claim 7, characterized in that: The insulating part further includes an insulating layer (13); The insulator (12) is covered with an insulating layer (13).

9. The cable according to claim 8, characterized in that: The insulator (12) is made of PP, PE, FEP or PFA; The insulating layer (13) is made of foam material.

10. The cable according to claim 9, characterized in that: The insulating layer (13) is wrapped around the insulator (12) in a wrapping manner; The first shielding layer (3) covers the outer side of the middle layer (2) in a vertically enclosing manner; The second shielding layer (4) is wrapped around the first shielding layer (3) in a wrapping manner.

11. The cable according to claim 1, characterized in that: The material of the middle layer (2) is PP, PE or FEP; The inner layer (2) is extruded and formed to cover the core wire (1).

12. The cable according to claim 1, characterized in that: The first shielding layer (3) and the second shielding layer (4) are both made of metal.

13. The cable according to claim 12, characterized in that: The first shielding layer (3) is aluminum foil or copper foil; The second shielding layer (4) is aluminum foil.

14. The cable according to claim 4, characterized in that: The protective layer (6) is a Mylar layer or a flame-retardant PET layer.

15. The cable according to claim 1, characterized in that: The ground wire (5) may be one or two; When there is one ground wire (5), the ground wire (5) is located on either side of the center line of the cable; When there are two ground wires (5), the two ground wires (5) are respectively set on both sides of the center line of the cable.

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