High-current-carrying flame-retardant flexible cable having combined conductor structure and used for equipment, and manufacturing method

Abstract

The present invention relates to a high-current-carrying flame-retardant flexible cable having combined conductor structure and used for equipment, and a manufacturing method. The high-current-carrying flame-retardant flexible cable having combined conductor structure and used for equipment comprises a cable combination conductor, an inner isolation layer, a braid layer, an outer isolation layer, and a sheath layer. The cable uses a creative application mode of a special structure of a combination conductor and an insulating layer coating a single conductor, such that it is guaranteed that the cable can bear transmission of instantaneous super-large impact current, and under the condition that the cross section of the conductor is not increased, the instantaneous safety application current-carrying capacity of the cable is increased by dozens of times, thereby guaranteeing the application safety of the cable. The cable combination conductor is formed by twisting a plurality of insulating wire cores in a layered and forward / reverse mode, each insulating wire core comprises a wire core conductor and an insulating layer wrapping the outside of the wire core conductor, and each wire core conductor is formed by twisting a plurality of strands of wire harnesses. According to the present invention, the eddy current effect can be effectively reduced, the transmission application safety of the cable subjected to instantaneous super-large impact current is guaranteed, and the cable is not prone to deformation during bending, and has excellent structural stability.

Description

High current-carrying flame-retardant flexible cable with combined conductor structure for equipment and manufacturing method thereof Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a high-current-carrying flame-retardant flexible cable with a combined conductor structure for equipment and a manufacturing method thereof. Background Art

[0002] With the rapid development of modern equipment, some high-power test instruments and testing equipment require cables with special performance to instantly transmit extremely large surge currents and meet the requirements for carrying high-power instantaneous charge transmission. Existing cables do not meet these requirements due to factors such as conductor structure, insulation material, and product performance. When used in this way, cable ablation can damage instruments or equipment, affecting equipment operation.

[0003] The existing technical solutions have the following shortcomings:

[0004] (1) The conductor structure of the existing experimental polyolefin insulated cable is a plurality of bare copper wires or tinned copper wires twisted together according to a certain rule and arrangement structure. Once a large alternating current is transmitted, a large eddy induced current (eddy induced current is also called eddy current, hereinafter referred to as eddy current) will be generated in the conductor. The thermal effect of the eddy current can cause the temperature of the conductor to rise to a very high level instantly, resulting in operational faults such as burning of the cable insulation layer or melting of the conductor.

[0005] (2) Conventional cable insulation materials include polyvinyl chloride, cross-linked polyethylene, halogen-free low-smoke polyolefin, and rubber. Due to factors such as operating temperature and material properties, they cannot meet the requirements of thermal effects caused by large current shocks.

[0006] (3) Existing cables are overloaded and subjected to high temperature applications. Multiple bending can easily cause thermal deformation of the cable insulation sheath. This deformation is plastic deformation and is difficult to return to its original shape after cooling. Repeated bending stress can easily cause the cable insulation layer and sheath layer to break and crack, leading to equipment failure and creating safety hazards.

[0007] Therefore, the present invention conceives a high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment and a manufacturing method to overcome the defects of the prior art.

[0008] Summary of the Invention

[0009] The purpose of the present invention is to provide a high-current-carrying flame-retardant flexible cable with a combined conductor structure for equipment and a manufacturing method, which can effectively reduce the eddy current effect, ensure the safety of the cable in transmission applications when subjected to instantaneous ultra-large impact currents, is not easily deformed when bent, and has good structural stability.

[0010] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0011] The present invention provides a high-current-carrying flame-retardant soft cable with a combined conductor structure for equipment, comprising a cable combined conductor and an inner insulating layer, a braided layer, an outer insulating layer and a sheath layer wrapped around the outside of the cable combined conductor and arranged in sequence from the inside to the outside; the cable combined conductor is composed of multiple insulated cores twisted in layers in forward and reverse directions, each insulated core comprises a core conductor and an insulating layer wrapped around the outside of the core conductor, each core conductor is composed of multiple strands of wire bundles twisted together, each strand of wire bundle is composed of multiple wires bundled together, and the bundling direction of the multiple wires is in the same direction as the twisting direction of the multiple strands of wire bundle.

[0012] In a preferred embodiment of the present invention, the diameter of a single wire is ≤0.08 mm.

[0013] In a preferred embodiment of the present invention, each core conductor is composed of 7 wire strands twisted in layers according to a 1+6 arrangement structure.

[0014] In a preferred embodiment of the present invention, the pitch-to-diameter ratio of the wire bundle is 20-25; the pitch-to-diameter ratio of the core conductor is 14-16 for the inner layer and 10-12 for the outer layer.

[0015] In a preferred embodiment of the present invention, the insulating layer is a modified polyetheretherketone layer, and the thickness of the insulating layer is 0.1-0.5 mm.

[0016] In a preferred embodiment of the present invention, the insulating layer is formed by extrusion using a semi-extrusion die, and the semi-extrusion die uses multiple die sleeves. Each die sleeve has at least one notch at its outlet, and the number of notches on each die sleeve is different, so that at least one raised marking strip is formed on the outer surface of the insulating wire core.

[0017] In a preferred embodiment of the present invention, multiple insulated wire cores are twisted in forward and reverse directions according to an arrangement structure of 1+6+12+…+6n, wherein 1≤n≤10, and n is a positive integer; the semi-extrusion die adopts three die sleeves, and the discharge ports of the three die sleeves are respectively provided with one notch, two notches and three notches, and the outer surfaces of the multiple insulated wire cores obtained by extruding the insulation layer using the extrusion die have one marking stripe, two marking stripes or three marking stripes, and are respectively recorded as one marking stripe core, two marking stripe cores and three marking stripe cores; the layers of the multiple insulated wire cores from the center to the outside are respectively recorded as the center layer, the first layer to the nth layer, and the 6n insulated wire cores contained in the nth layer are arranged in the order of one marking stripe core, two marking stripe cores and three marking stripe cores and are arranged repeatedly for a total of 2n times.

[0018] In a preferred embodiment of the present invention, the pitch ratio of each layer of the cable assembly conductor is 10-16, and the inner layer pitch is less than or equal to the outer layer pitch.

[0019] In a preferred embodiment of the present invention, the inner isolation layer and the outer isolation layer are both composed of polyester tape wrapped, the thickness of the polyester tape is 0.02-0.05 mm, the width of the polyester tape is less than or equal to 1.5-2.5 times the diameter of the wrapping, and the wrapping overlap rate of the polyester tape is 25-40%.

[0020] In a preferred embodiment of the present invention, the braided layer is an aramid fiber layer, and the braiding density of the braided layer is 80-90%.

[0021] In a preferred embodiment of the present invention, the sheath layer is an insulating grade silicone rubber layer.

[0022] The present invention also provides a method for manufacturing a high-current-carrying flame-retardant flexible cable with a combined conductor structure for equipment, comprising the following steps:

[0023] Bundling multiple wires to form a wire bundle;

[0024] Twisting a plurality of wire bundles to form a core conductor; wherein a bundling direction of the plurality of wires is in the same direction as a twisting direction of the plurality of wire bundles;

[0025] An insulating layer is wrapped around the outside of each core conductor to form an insulated core;

[0026] Multiple insulated cores are twisted in layers in both forward and reverse directions to form a cable composite conductor;

[0027] Wrap an inner isolation layer around the cable's combined conductor;

[0028] Wrap the braided layer around the inner isolation layer;

[0029] Wrap an outer isolation layer around the braided layer;

[0030] The sheath layer is wrapped around the outer isolation layer to form a high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment.

[0031] In a preferred embodiment of the present invention, the insulating layer is produced by extruding a modified polyetheretherketone material through a semi-extrusion die, and after the modified polyetheretherketone material is extruded onto the core conductor, it is first pre-cooled by air, then soaked in hot water, and then gradually cooled in sections by soaking in cold water; wherein, the balance coefficient between the mold core and the mold sleeve in the semi-extrusion die is 1.00-1.01, and the stretching ratio is 1.4-1.8.

[0032] In a preferred embodiment of the present invention, the high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment produced in the production method is the above-mentioned high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment.

[0033] As described above, the equipment-use combined conductor structure high current-carrying flame-retardant flexible cable and its manufacturing method of the present invention divide the entire cable combined conductor design into multiple insulated cores with small cross-sections. The core conductors in each insulated core are arranged in the same direction and twisted twice in layers, which solves the eddy current effect caused by the alternating transmission of large current in a single conductor. The multiple insulated cores are arranged in a positive and negative direction and twisted multiple times in layers, which has a stronger structural stability. The cable combined conductor is provided with four layers in total, and the two isolation layers mainly play the role of electrical isolation; a braided layer is provided between the two isolation layers, and when the cable is stretched and deformed, the two isolation layers are more flexible when deformed and bent; the outer jacket layer mainly plays a flame retardant protection role; thereby playing a better protective role for the cable combined conductor, forming a secondary insulation protection, and having a better flame retardant effect. The entire flexible cable can meet the function of carrying high-power charges and instantaneously transmitting ultra-large impact currents, and can be used in some high-power test instruments and test equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0035] in:

[0036] Figure 1 is a schematic cross-sectional view of a high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment provided by the present invention.

[0037] FIG2 is a schematic cross-sectional view of one of the core conductors provided by the present invention.

[0038] Explanation of the accompanying figures: 1. Cable combination conductor; 11. Core conductor; 12. Insulation layer; 2. Inner isolation layer; 3. Braided layer; 4. Outer isolation layer; 5. Sheath layer. DETAILED DESCRIPTION

[0039] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0040] As shown in Figures 1 and 2, this embodiment provides a high-current-carrying flame-retardant flexible cable with a combined conductor structure for equipment, including a cable combined conductor 1 and an inner insulating layer 2, a braided layer 3, an outer insulating layer 4 and a sheath layer 5 wrapped around the outside of the cable combined conductor 1 and arranged in sequence from the inside to the outside; the cable combined conductor 1 is composed of multiple insulated cores twisted in layers in forward and reverse directions, each insulated core includes a core conductor 11 and an insulating layer 12 wrapped around the outside of the core conductor 11, each core conductor 11 is composed of multiple strands of wire bundles twisted together, each strand of wire bundle is composed of multiple wires bundled together, and the bundling direction of the multiple wires is in the same direction as the twisting direction of the multiple strands of wire bundles.

[0041] Therefore, the equipment-use combined conductor structure high current-carrying flame-retardant flexible cable of this embodiment divides the entire cable combined conductor 1 into multiple small-section insulated cores. The core conductors 11 in each insulated core are arranged in the same direction and twisted twice in layers, which solves the eddy current effect caused by the alternating transmission of large current in a single conductor. Multiple insulated cores are arranged in a positive and negative direction and twisted multiple times in layers, which makes the structure more stable. The cable combined conductor 1 is provided with four layers in total, and the two isolation layers mainly play the role of electrical isolation; a braided layer 3 is provided between the two isolation layers, and when the cable is stretched and deformed, the two isolation layers are more flexible when deformed and bent; the sheath layer 5 mainly plays a flame retardant protection role; thereby playing a better protective role for the cable combined conductor 1, forming a secondary insulation protection, and having a better flame retardant effect. The entire flexible cable can meet the function of carrying high-power charge instantaneously and transmitting ultra-large impact current (i.e., high current carrying), and can be used in some high-power test instruments and test equipment.

[0042] In a specific implementation, the diameter of a single conductor is ≤0.08 mm. The conductor can be, for example, copper wire. Since the diameter of a single conductor is relatively thin, twisting multiple thin conductors together can effectively reduce eddy currents generated by conductor current changes.

[0043] 2 , each core conductor 11 is composed of 7 strands of wire bundles twisted in layers according to a 1+6 arrangement structure, which can meet the requirements of cross-sectional area and resistance while simplifying the process.

[0044] First, multiple wires are bundled into strands, and then twisted in the same direction according to a 1+6 arrangement structure to form a small-section core conductor 11. Since the strands have been bundled and then twisted, the original bundled strands are bound in a fixed area (refer to Figure 2), and are not prone to large displacement during bending, which may cause deformation of the stranded wire. The pitch-diameter ratio of the strands (i.e., the pitch-diameter ratio of the wire bundle) is controlled at 20-25, and the pitch-diameter ratio of the strands (the pitch-diameter ratio of the core conductor 11) is controlled at 14-16 for the inner layer and 10-12 for the outer layer. Since the direction of the bundle and the direction of the strand twisting are the same, the bundle pitch is appropriately reduced in the secondary twisting, resembling a primary bundle structure. Therefore, the core conductor 11 twisted into a small cross-section looks like a single conductor. It is placed on a guide wheel 10 times the diameter of the conductor and subjected to 3,000 bending tests. No single wire protrudes from the conductor, and no broken wire ends are exposed. This solves the problem of broken conductor cores, as well as the problem of damaged insulation layer 12 caused by conductor bending, broken ends, or protrusions, which affects product performance.

[0045] Multiple strands of annealed bundled flexible wires are twisted into a small-section core conductor 11 of a cable in a 1-strand + 6-strand arrangement. In a specific embodiment, 91 small-section core conductors 11 are twisted into a 95mm 2 Cable combination conductor 1,95mm 2The cable combination conductor 1 requires a DC resistance of no more than 0.206Ω / km at 20℃. The core conductor 11 divided into small cross-sections retains a 5% production process stretching margin. The DC resistance of each core should be controlled at no more than 17.8Ω / km. The calculation uses a single wire with a diameter of no less than 0.07mm, with no less than 36 strands per strand, twisted together. The strands and twisted wires are twisted in the same direction, which can reduce the outer diameter of the conductor and the core, and the core is softer.

[0046] The above-mentioned insulating layer 12 is preferably a modified polyetheretherketone layer.

[0047] When producing the insulating layer 12, a semi-extrusion die is used for extrusion production. The balance coefficient K value of the die core and the die sleeve is controlled between 1.00-1.01, and the stretching ratio S value is controlled between 1.4-1.8. The extrusion is tight and easy to peel off, which not only ensures the production speed, but also ensures the appearance quality of the extruded insulating layer 12.

[0048] During the extrusion coating process of the modified polyetheretherketone insulation layer, surface printing is difficult due to the small core diameter and high production line speed. Laser marking also affects production efficiency. Furthermore, due to the special properties of the material, it is expensive. For example, color separation production increases the variety and quantity of raw material colors to be stored, significantly increasing production and operating costs. In this embodiment, the insulation layer 12 is formed by extrusion using a semi-extrusion die. The semi-extrusion die uses multiple die sleeves, each of which has at least one notch at the outlet. The number of notches on each die sleeve varies, so that at least one raised marking stripe is formed on the outer surface of the insulated wire core.

[0049] The length direction of the aforementioned notch is arranged along the axial direction of the discharge port. When multiple notches are provided, the multiple notches are evenly spaced around the circumference. During extrusion, the presence of the notch can form a protrusion at this location on the resulting insulating layer 12, thereby forming a raised marking strip on the outer surface of the produced insulated wire core. The length direction of the marking strip extends along the axial direction of the insulated wire core. The specific number of die sets is determined according to needs. For example, in this embodiment, a total of three die sets are used. The discharge ports of the three die sets are respectively provided with one notch, two notches, and three notches. The outer surfaces of the produced insulated wire cores respectively have one marking strip, two marking strips, and three marking strips, so as to meet usage requirements and simplify the process. In this way, three die sleeves are used in the extrusion coating process. A notch is filed at the discharge port of one of the die sleeves, two notches are filed on another die sleeve, and three notches are filed on the remaining die sleeve. During extrusion, raised marking strips are formed at the notches on the die sleeves. Without changing the material color or printing the surface identification, the insulated wire cores can be identified and distinguished only by the number of raised identification lines on the surface of the insulated wire cores.

[0050] The modified polyetheretherketone insulation material is heated, plasticized, extruded, and tightly coated on the outside of the small-section core conductor 11 to form an insulation layer 12 that is resistant to high temperature, eddy current, and high current impact. The thickness of the insulation layer 12 is controlled within the range of 0.10-0.50mm, and the conductor cross-section is 1mm. 2 The thickness of the insulating layer 12 should be designed to be around 0.20-0.30mm. If the insulating layer 12 is too thin, the process will be difficult to control and the spark test will easily break down. If the insulating layer 12 is too thick, the outer diameter of the product will be too large, affecting the bending radius of the product. The insulating layer 12 is heated and plasticized by a high-temperature extruder. Air pre-cooling is first used, so the production line speed should not be too fast. Then it is soaked in hot water, and then soaked in cold water in sections to prevent the insulating layer 12 of the modified polyetheretherketone (PEEK) material from cooling too quickly and causing brittle stress, which may cause the insulating layer 12 to crack and fail to meet product performance requirements.

[0051] The insulation layer 12 is extruded and coated with modified polyetheretherketone (PEEK), a thermoplastic flame-retardant polymer material with high mechanical strength, high temperature resistance, corrosion resistance, hydrolysis resistance, impact resistance, fatigue resistance, and excellent electrical insulation properties. The modified polyetheretherketone insulation material has a high heat deformation temperature (up to 316°C). When transmitting extremely high currents, the cable conductor continues to operate stably at temperatures as high as 300°C, eliminating the potential for ablation of the insulation layer 12 due to high-temperature deformation. The product of this embodiment is not damaged by ablation due to sudden changes in current carrying capacity, ensuring normal equipment operation.

[0052] In an optional embodiment, the insulating layer 12 may also be made of materials such as silicone rubber and thermoplastic polyimide (TPI). The extrusion high-temperature resistance of these materials is generally similar, and the high-temperature resistance of polyimide is relatively excellent.

[0053] In actual use, a dedicated wire stripper is used to strip approximately 1 to 2 cm of the polyetheretherketone (PEEK) insulation layer 12 from the cable end. The cables are then crimped together into groups with terminal blocks and connected to a terminal block to form a single-phase cable conductor. The cables can transmit a current of no less than 1000A for a short period of 30 seconds, and a transient current of no less than 5000A. This eliminates the eddy current effects and thermal deformation issues associated with the transmission of very high alternating currents. The cables feature a high operating temperature, high transient current carrying capacity, and strong impact resistance, meeting the requirements for transient power transmission and grounding protection in high-power test instruments and testing equipment. They also exhibit flame retardancy, abrasion resistance, corrosion resistance, and flexible bending properties.

[0054] Furthermore, the plurality of insulated wire cores are twisted in forward and reverse directions according to an arrangement structure of 1+6+12+…+6n, where 1≤n≤10 and n is a positive integer. The outer surfaces of the plurality of insulated wire cores obtained by extruding the insulation layer using the above-mentioned extrusion die with three die sleeves have one marking stripe, two marking stripes, or three marking stripes, and are respectively recorded as one marking stripe core, two marking stripe cores, and three marking stripe cores; the layers of the plurality of insulated wire cores from the center outward are respectively recorded as the center layer, the first layer to the nth layer, and the 6n insulated wire cores contained in the nth layer are arranged in the order of one marking stripe core, two marking stripe cores, and three marking stripe cores, and the arrangement is repeated 2n times in total.

[0055] Specifically, in the arrangement of insulated cores, the center layer is any insulated core with an identification strip. The first layer of 6 insulated cores is arranged as one identification stripe core, two identification stripe cores, and three identification stripe cores, and then arranged in a cycle (i.e., arranged in a cycle twice in total); the second layer of 12 insulated cores is arranged as one identification stripe core, two identification stripe cores, and three identification stripe cores, and arranged in a cycle four times in total; the third layer of 18 cores is arranged as one identification stripe core, two identification stripe cores, and three identification stripe cores, and arranged in a cycle six times in total; and so on... In product application, the one identification stripe core, two identification stripe cores, and three identification stripe cores are connected separately and connected to the corresponding grouped line positions respectively; by connecting them in separate combinations to different positions, the current can be more evenly distributed to each small core for transmission. The pitch-to-diameter ratio of each layer in the cable combination conductor 1 is 10-16, the twisting is tight, and the inner layer pitch is not larger than the outer layer pitch. The smaller pitch-to-diameter ratio of the layered twisting and the inner and outer layer pitches are strictly controlled, ensuring the product's bending softness and bending deformation recovery function, and the stranded wire structure has better stability during multiple bending uses.

[0056] Furthermore, the inner isolation layer 2 and the outer isolation layer 4 are both formed by wrapping polyester tape, the thickness of the polyester tape is 0.02-0.05 mm, the width of the polyester tape is less than or equal to 1.5-2.5 times the wrapping diameter, and the wrapping overlap rate of the polyester tape is 25-40%.

[0057] The inner isolation layer 2 and the outer isolation layer 4 are formed by wrapping a polyester tape of a specific width. For example, in this embodiment, a polyester tape with a thickness of 0.03 mm and a width of 40 mm is used, and an overlap rate of about 33% is used for wrapping isolation. This not only increases the bending displacement sliding performance of the wrapping, and can quickly restore to its original shape after straightening, but also has electrical isolation and insulation properties, ensuring the softness of the product.

[0058] The braided layer 3 is an aramid fiber layer, and the braiding density of the braided layer 3 is 80-90%.

[0059] An aramid fiber braided layer 3 is provided between the inner isolation layer 2 and the outer isolation layer 4. Aramid fiber is used for braiding protection, and the braiding density is, for example, about 85%. The high-density braiding increases the protection function against deformation during tensile application.

[0060] The sheath layer 5 is an insulating grade silicone rubber layer.

[0061] High-temperature-resistant, insulating-grade silicone rubber cable sheathing material is extruded and tightly wrapped around an outer insulating layer 4 to form a flexible, flame-retardant sheath 5 that is resistant to bending, abrasion, corrosion, and deformation. After forming, the sheath 5 is cured and vulcanized in a step-temperature bath below 200°C for a set time, then cooled in a water bath. The extruded and vulcanized sheath 5 is easily peeled without adhering to the outer insulating layer 4. The cable offers high operating temperatures, high transient current carrying capacity, and strong impact resistance. It meets the requirements for transient power transmission and grounding protection in high-power test instruments and testing equipment, as well as flame retardancy, abrasion resistance, corrosion resistance, and flexible bending properties.

[0062] By using polyester tape with a thickness of 0.02-0.05mm and a width not exceeding 1.5-2.5 times the wrapping diameter on the outside of the cable combination conductor 1 for overlapping wrapping isolation, the wrapping overlap rate should be controlled within the range of 25%-40%; aramid fiber is used for weaving on the outside, and the weaving density is controlled between 80%-90%; polyester tape is wrapped around the outside of the braided layer 3 for effective isolation, and finally a flame-retardant sheath layer 5 is coated, thereby achieving effective protection for the cable combination conductor 1.

[0063] Furthermore, this embodiment also provides a method for manufacturing a high current-carrying flame-retardant flexible cable for equipment, comprising:

[0064] Bundling multiple wires to form a wire bundle;

[0065] The plurality of wire bundles are twisted to form a core conductor 11; wherein the bundling direction of the plurality of wires is in the same direction as the twisting direction of the plurality of wire bundles;

[0066] An insulating layer 12 is wrapped around the outside of each core conductor 11 to form an insulated core;

[0067] Multiple insulated cores are twisted in layers in forward and reverse directions to form a cable combination conductor 1;

[0068] Wrapping an inner isolation layer 2 around the cable combination conductor 1;

[0069] Wrap the braided layer 3 outside the inner isolation layer 2;

[0070] Wrap an outer isolation layer 4 outside the braided layer 3;

[0071] The outer insulating layer 4 is wrapped with a sheath layer 5 to form a high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment.

[0072] Furthermore, the insulating layer 12 is produced by extruding a modified polyetheretherketone material through a semi-extrusion die, and after the modified polyetheretherketone material is extruded onto the core conductor 11, it is first pre-cooled by air, then soaked in hot water, and then gradually cooled in sections by soaking in cold water; wherein, the balance coefficient between the mold core and the mold sleeve in the semi-extrusion die is 1.00-1.01, and the stretching ratio is 1.4-1.8.

[0073] The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment obtained by this manufacturing method is the high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment shown in Figures 1 and 2 above. The specific principles and effects have been described in detail above and will not be repeated here.

[0074] In summary, the high-current-carrying flame-retardant flexible cable with a combined conductor structure for equipment and the manufacturing method in this embodiment belong to the cables and manufacturing methods for modern high-power test instruments and test equipment. When the product is used, one identification strip core, two identification strip cores, and three identification strip cores are connected separately and respectively connected to the corresponding grouping line positions; when they are separated and combined and connected to different positions, the current can be distributed more evenly to each small core for transmission. The entire flexible cable adopts a creative application method of a special structure of a combined conductor and a high-temperature resistant material insulation layer wrapped around a single conductor, which ensures that the cable can withstand instantaneous ultra-large impact currents (cable conductor cross-section 1mm 2 Without increasing the conductor cross-section, the cable's instantaneous safe current carrying capacity is increased by dozens of times. The short-term current transmitted within 30 seconds is no less than 1000A, and the cable's instantaneous current transmission is no less than 5000A. This solves the eddy current effect and thermal deformation problems caused by the transmission of ultra-large alternating currents. Specifically, it can meet the application technology scope of ultra-large current instantaneous transmission, provide transmission performance for current ultra-high power electromagnetic conversion, and provide energy-saving protection for the power transmission wiring of high-power equipment. It has the following advantages:

[0075] (1) The cable conductor is made by first bundling multiple copper wires, and then twisting them in the same direction according to a 1+6 arrangement structure. When twisting in the same direction, some of the strand pitch will be withdrawn, which is similar to a one-time bundled structure. The product has a small outer diameter, is more flexible, and has high production efficiency. Multiple core conductors 11 are then twisted in the forward and reverse directions according to an arrangement structure of 1+6+12+18+24+30+…, and the stranded wire structure is more stable when bent multiple times. The entire cable combination conductor 1 is designed to be a plurality of small-section core conductors 11 with an insulating layer 12, which are then twisted together. When in use, the insulating layer 12 is stripped off and then pressed together with a terminal, which solves the eddy current effect caused by the alternating transmission of large currents in a single conductor twisted together by multiple metal wires;

[0076] (2) The insulating layer 12 is made of polyetheretherketone (PEEK), a thermoplastic flame-retardant polymer material with high mechanical strength, high temperature resistance, corrosion resistance, hydrolysis resistance, impact resistance, fatigue resistance, and good electrical insulation performance. The thermal deformation temperature of this material can reach above 316°C. This solves the problem of high-temperature deformation of the insulating layer 12 when the conductor temperature of ultra-high current cables reaches up to 300°C. The product of the present invention is not damaged by ablation due to sudden changes in current carrying capacity, and can ensure the normal operation of the equipment.

[0077] (3) The core conductor 11 is twisted in accordance with the standard test requirements. No single wire protrudes from the core conductor 11 and no wire breakage is exposed. Solve the problem of conductor breakage, as well as the problem of conductor bending, wire breakage or protrusion, which causes damage to the insulation layer 12 and affects product performance. Focus on controlling the extrusion design parameters, the extrusion is tight and easy to peel, and the thickness of the insulation layer 12 is controlled within a relatively thin range, ensuring that the outer diameter of the cable combination conductor 1 is not too large; the small pitch ratio twisting and overlapping polyester tape wrapping solve the performance requirements of the cable being soft and recovering to its original shape after deformation due to bending and movement. The use of aramid fiber for high-density braiding increases the protection function of application deformation. The flame-retardant soft cable is made of modified polyetheretherketone insulation silicone rubber material sheath and special process structure. The cable has a high operating temperature and strong impact resistance, and can meet the performance requirements of instantaneous power transmission and grounding conduction protection of high-power equipment.

[0078] The above is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention.

Claims

1. A high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment, characterized in that: It comprises a cable assembly conductor and an inner insulating layer, a braided layer, an outer insulating layer and a sheath layer which are wrapped around the outside of the cable assembly conductor and arranged in sequence from the inside to the outside; The cable combination conductor is composed of multiple insulated cores twisted in layers in forward and reverse directions, each of the insulated cores includes a core conductor and an insulating layer wrapped around the core conductor, each of the core conductors is composed of multiple strands of wire bundles twisted together, each strand of the wire bundle is composed of multiple wires bundled together, and the bundling direction of the multiple wires is in the same direction as the twisting direction of the multiple strands of the wire bundles.

2. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: The diameter of a single wire is ≤0.08 mm.

3. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: Each of the core conductors is composed of 7 strands of wire bundles twisted in layers according to a 1+6 arrangement structure.

4. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment as claimed in claim 3, characterized in that: The pitch-to-diameter ratio of the wire bundle is 20-25; the pitch-to-diameter ratio of the core conductor is 14-16 for the inner layer and 10-12 for the outer layer.

5. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: The insulating layer is a modified polyetheretherketone layer, and the thickness of the insulating layer is 0.1-0.5 mm.

6. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment as claimed in claim 5, characterized in that: The insulating layer is formed by extrusion production using a semi-extrusion die, and the semi-extrusion die uses a plurality of die sleeves. Each die sleeve is provided with at least one notch at the discharge port, and the number of notches on each die sleeve is different, so that at least one raised marking strip is formed on the outer surface of the insulating core.

7. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 6, characterized in that: The plurality of insulated wire cores are twisted in forward and reverse directions according to an arrangement structure of 1+6+12+…+6n, wherein 1≤n≤10, and n is a positive integer; The semi-extrusion die adopts three die sleeves, and the outlets of the three die sleeves are respectively provided with one notch, two notches and three notches. The outer surfaces of the plurality of insulated wire cores obtained by extruding the insulating layer by the extrusion die have one marking stripe, two marking stripes or three marking stripes, and are respectively recorded as one marking stripe wire core, two marking stripe wire core and three marking stripe wire core; the plurality of insulated wire cores are respectively provided with one marking stripe wire core, two marking stripe wire core and three marking stripe wire core; The outward layers are respectively recorded as the central layer, the first layer to the nth layer, and the 6n insulated cores contained in the nth layer are arranged in the order of one identification bar core, two identification bar cores and three identification bar cores and are arranged repeatedly for a total of 2n times.

8. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 7, characterized in that: The pitch ratio of each layer of the cable combination conductor is 10-16, and the inner layer pitch is less than or equal to the outer layer pitch.

9. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: The inner isolation layer and the outer isolation layer are both formed by wrapping polyester tape, the thickness of the polyester tape is 0.02-0.05 mm, the width of the polyester tape is less than or equal to 1.5-2.5 times the wrapping diameter, and the wrapping overlap rate of the polyester tape is 25-40%.

10. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: The braided layer is an aramid fiber layer, and the braiding density of the braided layer is 80-90%.

11. The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 1, characterized in that: The sheath layer is an insulating grade silicone rubber layer.

12. A method for manufacturing a high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment, characterized in that: The steps include: Bundling a plurality of wires to form a wire bundle; Twisting the plurality of wire bundles to form a core conductor; wherein the bundling direction of the plurality of wires is in the same direction as the twisting direction of the plurality of wire bundles; Wrapping an insulating layer around each of the core conductors to form an insulated core; Twisting the plurality of insulated wire cores in layers in forward and reverse directions to form a cable combined conductor; Wrapping an inner insulating layer outside the cable combination conductor; Wrapping a braided layer outside the inner isolation layer; Wrapping an outer isolation layer outside the braided layer; A sheath layer is wrapped outside the outer isolation layer to form a high current-carrying flame-retardant soft cable with a combined conductor structure for equipment.

13. The method for manufacturing the high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 12, characterized in that: The insulating layer is produced by extruding a modified polyetheretherketone material through a semi-extrusion die, and the modified After the polyetheretherketone material is extruded onto the core conductor, it is first pre-cooled by air, then soaked in hot water, and then gradually cooled in sections by soaking in cold water.

14. The method for manufacturing the high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment according to claim 12, characterized in that: The high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment is the high current-carrying flame-retardant flexible cable with a combined conductor structure for equipment as described in any one of claims 1-11.

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