Flame-retardant A-level segmented armored fireproof cable and method

Abstract

The invention relates to the technical field of flame-retardant cables, in particular to a flame-retardant A-level sectional type armored fireproof cable and a method, the fireproof cable is composed of a cable section, a cable section adapter and a cable section connecting terminal, the length of a continuous metal armored layer is shortened in use, eddy current loss in a use scene is reduced, and the service life of the cable is prolonged. The modularized packaging wire core units are adopted, so that the whole wire core structure is changed into a plurality of modularized packaging wire core units, bending stress received in the use process can be dispersed, meanwhile, each conductor wire core is shielded by an independent metal isolation frame, the influence of crosstalk is reduced, and in the aspect of cable material selection, the cost is reduced. According to the fireproof cable, inorganic materials are adopted, and the metal isolation frame structure is arranged, so that the damage of the insulating layer in the extrusion process can be greatly reduced during the processing of the cable, the insulation resistance of the cable is improved, and the problem that the insulation resistance between wire cores of the fireproof cable is not up to the standard is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flame-retardant cables, and specifically to a flame-retardant Class A segmented armored fireproof cable and method. Background Art

[0002] An armored cable is composed of conductors of different materials installed in a metal sleeve of insulating material and processed into a bendable solid combination. Armored cables include armored thermocouples, armored thermal resistors, armored heaters, and armored leads, and are mainly used in scenarios such as chemical industry, metallurgy, machinery manufacturing, and power generation.

[0003] In some specific usage scenarios, there are strict requirements for the flame-retardant performance of armored cables, and they need to reach flame-retardant Class A, that is, meet the Class A standard of "Combustion Tests of Cables and Optical Fibre Cables under Fire Conditions" in the GB / T18380-2008 test standard.

[0004] On the one hand, when the existing armored fireproof cables are manufactured, they contain some combustible materials or materials with low ignition points, and there is a certain probability of combustion in the event of a fire, making it difficult to ensure that the products meet the requirements of Class A combustion performance. At the same time, these cables contain organic materials. For example, the Chinese patent with publication number CN114758829A discloses a high-cold-resistant special-shaped armored Central Asia cable, which contains components such as polyvinyl chloride resin, DOP, and DOS, and may produce toxic gases after combustion, causing secondary harm to the escaping people. At the same time, the Chinese patent with publication number CN107393645A discloses a chip-embedded plastic armored intelligent power cable for smart energy, which also uses materials such as polyvinyl chloride and polyester-type plastics in layer structures such as the armored part and the inner lining part.

[0005] On the other hand, in the context of Industry 4.0, higher requirements are put forward for the performance of cables. First of all, industrial robots are often in high-safety-risk environments, and cables need to have extremely high flame-retardant performance to prevent the spread of fire and ensure the safety of personnel and equipment. Secondly, the traditional cable structure adopts an overall encapsulation structure in design and production, that is, all conductor cores in the cable are integrally protected by a protective layer and an armored layer. Although this reduces the production cost of the cable, the stress during use is concentrated, and it is easy to crack under repeated bending. At the same time, the dense arrangement of multiple conductor cores may cause crosstalk. When used as a signal transmission cable, it affects the control accuracy of industrial robots. Moreover, in the event of accidental damage, the entire cable needs to be replaced.

[0006] Thirdly, in new energy scenarios such as photovoltaic power generation, there are often requirements for cables to be resistant to high temperatures, withstand high voltages and large currents. In the cable design schemes disclosed in the existing literature mentioned above, a continuous metal armored structure is adopted, and there is a possibility of forming a large closed loop during power transmission, which is prone to eddy currents and eddy current losses. Summary of the Invention

[0007] The object of the present invention is to provide a flame-retardant Class A segmented armored fireproof cable and method in view of the above existing problems.

[0008] The technical solution adopted by the present invention is as follows. A flame-retardant Class A segmented armored fireproof cable includes cable segments, cable segment adapters, and cable segment connection terminals;

[0009] Two or more encapsulated core units are included in the cable segment, and adjacent encapsulated core units are independent of each other. Both ends of the cable segment are respectively connected to the cable segment adapter;

[0010] The cable segment adapter is connected to the cable segment connection terminal, and the segmented cable segments are connected through the cable segment connection terminal;

[0011] The encapsulated core unit is made of inorganic materials.

[0012] Optionally, the encapsulated core unit includes a conductor core, a metal isolation frame, a core filling layer, and an insulating layer;

[0013] The insulating layer wraps around the outer periphery of the conductor core and can be inserted into the metal isolation frame;

[0014] The core filling layer is filled between the insulating layer and the inner wall of the metal isolation frame;

[0015] The metal isolation frame is in a fan-shaped structure.

[0016] Optionally, the cable segment further includes a positioning core, a protective layer, and a steel stranded armor;

[0017] The encapsulated core units are arranged around the positioning core, and one end of the encapsulated core unit abuts against the positioning core;

[0018] The protective layer wraps around the arc surface of the encapsulated core unit and wraps the positioning core and the encapsulated core unit into a cylindrical structure;

[0019] The steel stranded armor is stranded and coated on the outer periphery of the protective layer.

[0020] Optionally, the protective layer is wrapped with an inorganic mineral mica tape;

[0021] The core filling layer contains a mixture of aluminum hydroxide, magnesium hydroxide, zinc borate, and aluminum oxide;

[0022] The insulating layer is wrapped with an inorganic mineral mica tape;

[0023] The conductor core is an oxygen-free copper conductor.

[0024] Optionally, the cable segment adapter can be sleeved on the end of the cable segment. A positioning convex block is arranged on the outer periphery of the cable segment adapter, and a first positioning magnetic block is filled in the positioning convex block.

[0025] Optionally, the cable segment connection terminal has a cylindrical structure. Both ends of the cable segment connection terminal can be inserted into the cable segment adapter. The cable segment connection terminal includes a connection positioning unit and a core connection unit;

[0026] The core connection unit includes an electrical connection piece and a connection insulating tape;

[0027] The electrical connection piece is arranged in the connection insulating tape, and the conductor cores in the two cable segments to be connected can be inserted into the electrical connection piece to form an electrical connection;

[0028] The connection positioning unit includes a positioning ring platform and a second positioning magnetic block group;

[0029] The positioning ring platform is arranged on the outer periphery of the connection insulating tape, and the center of the positioning ring platform coincides with the center of the cable segment connection terminal;

[0030] The second positioning magnetic block group contains the same number of second positioning magnetic blocks as the first positioning magnetic block, and the second positioning magnetic block can attract the first positioning magnetic block.

[0031] Optionally, the linear distance between the first positioning magnetic block and the nearest conductor core is greater than 30 mm;

[0032] The linear distance between the second positioning magnetic block and the nearest electrical connection piece is greater than 30 mm;

[0033] Both the first positioning magnetic block and the second positioning magnetic block have a cylindrical structure, and the outer peripheries of the first positioning magnetic block and the second positioning magnetic block are wrapped with permalloy shielding sheets.

[0034] The present application provides a production method for a flame-retardant Class A segmented armored fireproof cable for producing the above-mentioned flame-retardant Class A segmented armored fireproof cable, including the following steps:

[0035] S1. Determine the structure of the fireproof cable, including determining the number of encapsulated core units used and the length of the fireproof cable;

[0036] S2. Based on the number of encapsulated core units used in the fireproof cable to be produced, process the metal isolation frame by extrusion molding;

[0037] S3. Stranding the conductor single wires at one time to obtain conductor strands, and then re-stranding the conductor strands to obtain conductor cores;

[0038] S4. Wind and wrap an inorganic mineral mica tape around the outer periphery of the conductor core to form an insulating layer;

[0039] S5. Insert the conductor core with an insulating layer into the metal isolation frame, fill a core filling layer between the insulating layer and the metal isolation frame, and encapsulate to obtain an encapsulated core unit;

[0040] S6. Select a determined number of encapsulated core units, arrange them around the positioning core, and make the top of the encapsulated core unit abut against the positioning core. Then wind and wrap the inorganic mineral mica tape around the arc surface of the encapsulated core unit to form a cylindrical unit to be armored;

[0041] S7. Strands of steel wire are stranded on the unit to be armored in a double-layer and duplex manner to form a steel wire stranded armor, and a cable section is obtained;

[0042] S8. Install cable section adapters at both ends of the cable section, and assemble the cable sections through cable section connection terminals according to the length of the fire-resistant cable to obtain a fire-resistant cable with the target length.

[0043] Optionally, in S5, both ends of the conductor core expose 10 mm - 30 mm from the metal isolation frame, and both ends of the conductor core can be inserted into the cable section connection terminals.

[0044] Optionally, in S8, first insert the cable section adapter of the cable section into the cable section connection terminal, then make the first positioning magnetic block and the second positioning magnetic block match in position and perform magnetic attraction, so that the conductor core is inserted into the electrical connection piece of the cable section connection terminal, and finally fasten the cable section adapter and the cable section connection terminal with fasteners.

[0045] The beneficial effects of the present invention at least include one of the following;

[0046] 1. The design of the sectional armored fire-resistant cable is adopted from two dimensions. One dimension is that the fire-resistant cable is composed of a cable section, a cable section adapter, and a cable section connection terminal. During use, the length of the continuous metal armor layer is shortened, and the eddy current loss in the use scenario is reduced. The other dimension is that the modular structure of the encapsulated core unit is adopted, so that the overall core structure becomes multiple modular encapsulated core units. In this way, the bending stress received during use can be dispersed, and at the same time, each conductor core has an independent metal isolation frame for shielding, reducing the influence of crosstalk.

[0047] 2. In terms of the selection of cable materials, inorganic materials are used. By setting the metal isolation frame structure, it can be ensured that during the processing of the cable, the damage to the insulating layer during the extrusion process is greatly reduced, the insulation resistance of the cable is improved, and the problem that the insulation resistance between the cores of the fire-resistant cable is not up to standard is solved.

[0048] 3. The metal isolation frame encloses the conductor core, which can offset most of the magnetic field effects and improve the stability of power transmission of the insulated core; and the new material of the double-phase high-temperature resistant stainless steel wire stranded layer is adopted, which can ensure that the cable does not deform under the flame condition of 1200 °C, effectively isolate the flame, and at the same time, the stranded structure can improve the bending performance of the cable; the inorganic material is adopted in the structure of the cable section, and it is also non-toxic, so that the product meets the requirements of Class A combustion performance and non-toxic requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 FIG. is a schematic structural diagram of a cable section of a flame-retardant Class A segmented armored fireproof cable;

[0050] Figure 2 FIG. is a schematic connection diagram of a flame-retardant Class A segmented armored fireproof cable and a cable section adapter;

[0051] Figure 3 FIG. is a schematic structural diagram of a cable section connection terminal;

[0052] Figure 4 FIG. is a schematic overall connection diagram of a flame-retardant Class A segmented armored fireproof cable;

[0053] Figure 5 FIG. is a schematic assembly diagram of a flame-retardant Class A segmented armored fireproof cable.

[0054] In the figure:

[0055] 1 is a positioning core, 2 is a packaged core unit, 21 is a conductor core, 22 is a metal isolation frame, 23 is a core filling layer, 24 is an insulating layer, 3 is a protective layer, 4 is a steel wire stranded armor, 5 is a cable section adapter, 6 is a positioning bump, 7 is a first positioning magnetic attraction block, 8 is a cable section connection terminal, 9 is an electrical connection piece, 10 is a second positioning magnetic attraction block, 11 is a positioning ring platform, 12 is a connecting insulating tape, 13 is an insertion cavity, 14 is a first cable section, 15 is a second cable section, 16 is a pushing groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0058] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0059] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0060] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0061] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "install", "connect", "couple" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] As Figure 1 shown, a flame-retardant Class A segmented armored fireproof cable includes cable segments, a cable segment adapter 5, and a cable segment connection terminal 8;

[0063] Two or more encapsulated core units 2 are included in the cable segment, and adjacent encapsulated core units 2 are independent of each other. Both ends of the cable segment are respectively connected to the cable segment adapter 5;

[0064] The cable segment adapter 5 is connected to the cable segment connection terminal 8, and the segmented cable segments are connected through the cable segment connection terminal 8;

[0065] The encapsulated core unit 2 is made of inorganic materials.

[0066] The purpose of such a design is to adopt the design of a segmented armored fire-resistant cable from two dimensions. One dimension is to form a fire-resistant cable by using cable segments, cable segment adapters, and cable segment connection terminals, which shortens the length of the continuous metal armored layer during use and reduces the eddy current loss in the use scenario. The other dimension is to adopt the modular structure of the encapsulated core unit, so that the overall core structure becomes multiple modular encapsulated core units, and the bending stress received during use can be dispersed, and the influence of crosstalk can be reduced. At the same time, inorganic materials are used and it is also non-toxic, making the product meet the requirements of Class A combustion performance and non-toxic requirements.

[0067] Meanwhile, in this embodiment, the encapsulated core unit 2 includes a conductor core 21, a metal isolation frame 22, a core filling layer 23, and an insulating layer 24;

[0068] The insulating layer 24 wraps around the outer periphery of the conductor core 21 and can be inserted into the metal isolation frame 22;

[0069] The core filling layer 23 is filled between the insulating layer 24 and the inner wall of the metal isolation frame 22;

[0070] The metal isolation frame 22 has a fan-shaped structure.

[0071] Meanwhile, the cable segment further includes a positioning core 1, a protective layer 3, and a steel stranded armor 4;

[0072] The encapsulated core unit 2 is arranged around the positioning core 1, and one end of the encapsulated core unit 2 abuts against the positioning core 1;

[0073] The protective layer 3 wraps around the arc surface of the encapsulated core unit 2 and wraps the positioning core 1 and the encapsulated core unit 2 into a cylindrical structure;

[0074] The steel stranded armor 4 is stranded and coated on the outer periphery of the protective layer 3.

[0075] Furthermore, the protective layer 3 is wound with an inorganic mineral mica tape;

[0076] The core filling layer 23 contains a mixture of aluminum hydroxide, magnesium hydroxide, zinc borate, and aluminum oxide;

[0077] The insulating layer 24 is wound with an inorganic mineral mica tape;

[0078] The conductor core 21 is an oxygen-free copper conductor.

[0079] The purpose of such a design is that in terms of the selection of cable materials, inorganic materials are used. By setting up a metal isolation frame structure, it can ensure that during the cable processing, the damage to the insulation layer during extrusion is greatly reduced, the insulation resistance of the cable is improved, and the problem that the insulation resistance between the conductor cores of the fireproof cable is not up to standard is solved. At the same time, the metal isolation frame encloses the conductor cores therein, which can offset most of the magnetic field effects and enhance the stability of the insulated core for power transmission. And by using a new material, the double-phase high-temperature resistant stainless steel wire stranded layer, it can ensure that the cable does not deform under the flame condition of 1200 °C, can effectively isolate the flame, and at the same time, the stranded structure can improve the bending performance of the cable. The structure of the cable section uses inorganic materials and does not contain toxins, making the product meet the requirements of Class A combustion performance and non-toxic requirements.

[0080] In this embodiment, a specific composition of the core filling layer is provided. Calculated by weight, it contains 35 parts of aluminum hydroxide, 15 parts of magnesium hydroxide, 10 parts of zinc borate, and 5 parts of aluminum oxide. On the one hand, the aluminum hydroxide and magnesium hydroxide form a compound system. The two have different flame retardant temperature ranges and can complement each other, thus covering a wider flame retardant temperature range. In the event of a sudden combustion, the two decompose and release water vapor to further reduce the surface temperature and oxygen concentration of the material.

[0081] On the other hand, the added zinc borate can cooperate with aluminum hydroxide and magnesium hydroxide to generate a more stable composite oxide, thereby forming a dense protective layer to isolate oxygen and inhibit heat transfer.

[0082] The set aluminum oxide, on the one hand, has high temperature resistance, and on the other hand, it can form an AI-Zn-B-O glass phase structure with zinc borate to enhance the overall thermal shock stability.

[0083] As Figure 2 shown, in this embodiment, a specific structure of a cable section adapter is provided. The cable section adapter 5 can be sleeved on the end of the cable section. A positioning convex block 6 is provided on the outer periphery of the cable section adapter 5, and a first positioning magnetic block 7 is filled in the positioning convex block 6.

[0084] At the same time, as Figure 3 shown, in this embodiment, a specific structure of a cable section connection terminal is provided. The cable section connection terminal 8 has a cylindrical structure. Both ends of the cable section connection terminal 8 can be inserted into the cable section adapter 5. The cable section connection terminal 8 includes a connection positioning unit and a core connection unit;

[0085] The core connection unit includes an electrical connection piece 9 and a connection insulating tape 12;

[0086] The electrical connection piece 9 is arranged in the connection insulating tape 12, and the conductor cores 21 in the two cable sections to be connected can be inserted into the electrical connection piece 9 to form an electrical connection;

[0087] The connection and positioning unit includes a positioning ring platform 11 and a second positioning magnetic block group;

[0088] The positioning ring platform 11 is arranged on the outer periphery of the connecting insulating tape 12, and the center of the positioning ring platform 11 coincides with the center of the cable section connection terminal 8;

[0089] The second positioning magnetic block group contains the same number of second positioning magnetic blocks 10 as the first positioning magnetic blocks 7, and the second positioning magnetic blocks 10 can attract the first positioning magnetic blocks 7.

[0090] Moreover, the straight-line distance between the first positioning magnetic block 7 and the nearest conductor core 21 is greater than 30 mm;

[0091] The straight-line distance between the second positioning magnetic block 10 and the nearest electrical connection piece 9 is greater than 30 mm;

[0092] Both the first positioning magnetic block 7 and the second positioning magnetic block 10 are cylindrical structures, and the outer peripheries of the first positioning magnetic block 7 and the second positioning magnetic block 10 are wrapped with permalloy shielding sheets.

[0093] The purpose of such a design is that since the cable structure provided by the technical solution of this embodiment is assembled by multiple encapsulated core units, the position matching requirements of the conductor cores in each encapsulated core unit are more stringent. Therefore, during the assembly of multiple cable sections using a cable section adapter, it is necessary to align the positions of the conductor cores. Thus, positioning magnetic blocks are used for assistance, which facilitates the alignment of the cable section adapter with the cable section connection terminal during subsequent use, and also enables the assembler to quickly determine whether the cable section adapter is compatible with the cable section.

[0094] It should be noted that during the simple power transmission of the cable, the magnetic field generated by the positioning magnetic blocks will not affect or significantly affect the power transmission. However, when used as a signal transmission cable, it will have a certain impact. Therefore, in this embodiment, on the one hand, the positioning magnetic blocks are set far away from the conductor cores, and on the other hand, permalloy shielding sheets are selected to reduce the influence of the positioning magnetic blocks on the conductor cores axially.

[0095] After testing, when the straight-line distance between the first positioning magnetic block 7 and the nearest conductor core 21 is greater than 30 mm;

[0096] When the straight-line distance between the second positioning magnetic block 10 and the nearest electrical connection piece 9 is greater than 30 mm, the overall magnetic field attenuation is about 70%. After being paired with permalloy shielding sheets, it can meet the requirements of general industrial scenarios. Of course, when those skilled in the art implement this solution and face some more demanding industrial scenarios, they can choose to add other existing structures for active filtering to reduce magnetic field interference to further reduce magnetic field interference.

[0097] In this embodiment, a production method for producing the flame-retardant Class A segmented armored fireproof cable in the above embodiment is provided, including the following steps:

[0098] S1. Determine the structure of the fireproof cable, including determining the number of encapsulated core units 2 used and the length of the fireproof cable;

[0099] S2. Process the metal isolation frame 22 by extrusion molding based on the number of encapsulated core units 2 used for the fireproof cable to be produced;

[0100] S3. Stranding the conductor single wires once to obtain conductor strands, and then re-stranding the conductor strands to obtain the conductor core 21;

[0101] S4. Wind and wrap the inorganic mineral mica tape around the outer periphery of the conductor core 21 to form the insulating layer 24;

[0102] S5. Insert the conductor core 21 with the insulating layer 24 into the metal isolation frame 22, and fill the core filling layer 23 between the insulating layer 24 and the metal isolation frame 22, and encapsulate to obtain the encapsulated core unit 2;

[0103] S6. Select a determined number of encapsulated core units 2, arrange them around the positioning core 1, and the top of the encapsulated core unit 2 abuts against the positioning core 1, and then wind and wrap the inorganic mineral mica tape around the arc surface of the encapsulated core unit 2 to form a cylindrical unit to be armored;

[0104] S7. Strand the steel wires on the unit to be armored in a double-layer and two-phase manner to form the steel wire stranded armor 4, and obtain the cable section;

[0105] S8. Install the cable section adapter 5 at both ends of the cable section, and assemble the cable sections through the cable section connection terminals 8 according to the length of the fireproof cable to obtain the fireproof cable with the target length.

[0106] Moreover, in S5, both ends of the conductor core 21 protrude 10 mm - 30 mm from the metal isolation frame 22, and both ends of the conductor core 21 can be inserted into the cable section connection terminal 8.

[0107] Furthermore, in S8, first insert the cable section adapter 5 of the cable section into the cable section connection terminal 8, then make the positions of the first positioning magnetic block 7 and the second positioning magnetic block 10 match and perform magnetic attraction, so that the conductor core 21 is inserted into the electrical connection piece 9 of the cable section connection terminal 8, and finally fasten the cable section adapter 5 and the cable section connection terminal 8 through fasteners.

[0108] In specific use, three, four or more encapsulated core units 2 will be selected according to actual needs to form a segmented armored fireproof cable, such asFigure 5 As shown, five packaged wire core units are selected for assembly, but as the number of packaged wire core units used increases, the cost of use will further increase, so on-site staff is required to conduct a value assessment. Although the technical solution provided in this application adopts a segmented and modular unit design to improve the overall performance of the cable, this design will inevitably lead to an increase in cost.

[0109] like Figure 4 As shown, a schematic diagram of two cable segments, namely a first cable segment 14 and a second cable segment 15, is provided through two cable segment adapters and a cable segment connecting terminal. After the cable segment is obtained through the above steps, its end is inserted into the cable segment adapter and tightened, and at the same time, the conductor core is passed through the cable segment adapter to extend into the cable segment connecting terminal.

[0110] Then push the cable segment adapter into the push slot of the cable segment connection terminal, and adjust the angle of the cable segment adapter so that the first positioning magnetic block fits with the second positioning magnetic block and then reaches the bottom of the push slot. At this time, the conductor core can enter the insertion cavity of the electrical connection piece to complete the connection. The other side is processed in the same way.

[0111] It should be noted that the electrical connecting piece is usually in an I-shaped structure, and the conductor cores can be inserted into both sides.

[0112] It should also be pointed out that in the current operation steps, the cable segment adapter and the cable segment connection terminal are still at the level of magnetic connection positioning, and the overall connection is not yet firm. Therefore, after completing the above steps, a better solution is to further strengthen the connection between the two through an external fixing bolt or a snap-on structure. Since this belongs to the prior art, technical personnel in this field can make a choice according to actual needs.

[0113] In order to prove the corresponding technical effect in this embodiment, corresponding tests were carried out. At the same time, it should be pointed out that the part that reflects the effect in this technical solution is mainly concentrated in the cable segment, and the cable segment adapter and the cable segment connection terminal are more often connected in sections. Therefore, the cable segment is selected in this test for:

[0114] Select a cable segment with a length of 100 mm, ambient temperature: 23±2℃, humidity 50±5%RH;

[0115] Before the test, the cable was placed in an aging box and heat aged at 105°C for 24 hours (simulating long-term use);

[0116] Surface cleaning: Wipe with anhydrous ethanol to remove surface contaminants.

[0117] Based on the GB / T18380-2008 test standard, a single vertical burning test is conducted:

[0118] Apparatus: Vertical burning test chamber.

[0119] Steps:

[0120] (1) Strip the cable section, select the encapsulated core unit and fix it on the bracket, and apply a flame at a position 500 mm from the top end;

[0121] (2) Flame action time: Remove the heat source after 10 seconds, and record the self-extinguishing time and the situation of the cotton pad being ignited by the dripping matter;

[0122] (3) Measure the flame spread distance.

[0123] Result: No combustion occurred, no flame spread occurred, and the cotton pad did not burn, meeting Class A standards.

[0124] Based on the GB / T18380-2008 test standard, a vertical burning test of bunched cables was carried out:

[0125] Apparatus: Bunched burning test rack.

[0126] Steps:

[0127] (1) Apply an open flame in the middle of the cable through an alcohol blowtorch, with a flame height of 20 - 30 mm, and continuously burn for 20 minutes;

[0128] (2) Monitor the flame spread distance and the characteristics of the dripping matter;

[0129] (3) After combustion, detect the structural integrity of the cable surface armor layer.

[0130] Result: No combustion occurred, no flame spread occurred, the cotton pad did not burn, and the armor layer structure was intact, meeting Class A standards.

[0131] Total calorific value measurement was carried out:

[0132] Steps:

[0133] (1) Take a 100 g cable section sample and place it in an oxygen bomb calorimeter, with an oxygen filling pressure of 3.0 MPa;

[0134] (2) After ignition, completely burn it and record the total heat release;

[0135] (3) Calculate the calorific value per unit mass, that is, PCS = total heat / sample mass.

[0136] Result: In this embodiment, the PCS of the cable section is 1.8 MJ / kg, and the typical value of traditional PVC cables > 15 MJ / kg.

[0137] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flame retardant Class A segmented armored fireproof cable, characterized in that: It comprises a cable segment, a cable segment adapter (5) and a cable segment connecting terminal (8); The cable segment contains more than two packaged wire core units (2), and adjacent packaged wire core units (2) are independent of each other, and both ends of the cable segment are respectively connected to the cable segment adapter (5); The cable segment adapter (5) is connected to the cable segment connection terminal (8), and the segmented cable segments are connected via the cable segment connection terminal (8); The packaged wire core unit (2) is made of inorganic material.

2. A flame-retardant Class A segmented armored fireproof cable according to claim 1, characterized in that: The packaged wire core unit (2) comprises a conductor wire core (21), a metal isolation frame (22), a wire core filling layer (23) and an insulating layer (24); The insulating layer (24) is wrapped around the outer periphery of the conductor core (21) and can be inserted into the metal isolation frame (22); The wire core filling layer (23) is filled between the insulating layer (24) and the inner wall of the metal isolation frame (22); The metal isolation frame (22) has a fan-shaped structure.

3. A flame-retardant Class A segmented armored fireproof cable according to claim 2, characterized in that: The cable segment further comprises a positioning core (1), a protective layer (3) and a twisted steel wire armor (4); The encapsulated wire core unit (2) is arranged around the positioning core (1), and one end of the encapsulated wire core unit (2) is in contact with the positioning core (1); The protective layer (3) is wrapped on the arc surface of the packaged wire core unit (2), and wraps the positioning core (1) and the packaged wire core unit (2) into a cylindrical structure; The steel wire twisted armor (4) is twisted and coated on the outer periphery of the protective layer (3).

4. A flame-retardant Class A segmented armored fireproof cable according to claim 3, characterized in that: The protective layer (3) is wrapped with an inorganic mineral mica tape; The wire core filling layer (23) comprises a mixture of aluminum hydroxide, magnesium hydroxide, zinc borate and aluminum oxide; The insulating layer (24) is wrapped with an inorganic mineral mica tape; The conductor core (21) is an oxygen-free copper conductor.

5. The flame-retardant Class A segmented armored fireproof cable according to claim 2, characterized in that: The cable segment adapter (5) can be sleeved on the end of the cable segment, a positioning protrusion (6) is provided on the outer periphery of the cable segment adapter (5), and the positioning protrusion (6) is filled with a first positioning magnetic attraction block (7).

6. A flame-retardant Class A segmented armored fireproof cable according to claim 5, characterized in that: The cable segment connection terminal (8) has a cylindrical structure, and both ends of the cable segment connection terminal (8) can be inserted into the cable segment adapter (5). The cable segment connection terminal (8) comprises a connection positioning unit and a wire core connection unit. The wire core connection unit comprises an electrical connection sheet (9) and a connection insulating tape (12); The electrical connection piece (9) is arranged in the connection insulating tape (12), and the conductor cores (21) in the two cable segments to be connected can be inserted into the electrical connection piece (9) to form an electrical connection; The connection positioning unit comprises a positioning ring platform (11) and a second positioning magnetic attraction block group; The positioning ring (11) is arranged on the outer periphery of the connecting insulating tape (12), and the center of the positioning ring (11) coincides with the center of the cable segment connecting terminal (8); The second positioning magnetic attraction block group comprises second positioning magnetic attraction blocks (10) whose number is equal to that of the first positioning magnetic attraction blocks (7), and the second positioning magnetic attraction blocks (10) can be attracted to the first positioning magnetic attraction blocks (7).

7. A flame-retardant Class A segmented armored fireproof cable according to claim 6, characterized in that: The straight-line distance between the first positioning magnetic block (7) and the nearest conductor core (21) is greater than 30 mm; The straight-line distance between the second positioning magnetic block (10) and the nearest electrical connection piece (9) is greater than 30 mm; The first positioning magnetic attraction block (7) and the second positioning magnetic attraction block (10) are both cylindrical structures, and the outer circumferences of the first positioning magnetic attraction block (7) and the second positioning magnetic attraction block (10) are wrapped with a Permalloy shielding sheet.

8. A method for producing a flame-retardant A-class segmented armored fireproof cable, used for producing a flame-retardant A-class segmented armored fireproof cable as claimed in claim 6 or 7, characterized in that: The following steps are involved: S1. Determine the structure of the fireproof cable, including determining the number of encapsulated core units (2) to be used and the length of the fireproof cable; S2. Based on the number of encapsulated core units (2) used in the fireproof cable to be produced, a metal isolation frame (22) is processed by extrusion molding; S3. Twisting the conductor single wires once to obtain conductor strands, and then re-twisting the conductor strands to obtain a conductor core (21); S4. Wrapping an inorganic mineral mica tape around the outer periphery of the conductor core (21) to form an insulating layer (24); S5. inserting the conductor core (21) with the insulating layer (24) into the metal isolation frame (22), filling the core filling layer (23) between the insulating layer (24) and the metal isolation frame (22), and encapsulating to obtain an encapsulated core unit (2); S6. Select a certain number of encapsulated wire core units (2), surround and arrange them around the positioning core (1), and the top of the encapsulated wire core unit (2) is in contact with the positioning core (1), and then the inorganic mineral mica tape is wrapped around the arc surface of the encapsulated wire core unit (2) to form a cylindrical unit to be armored; S7. The steel wire is twisted in a double-layer and double-phase manner on the armored unit to form a steel wire twisted armor (4) to obtain a cable segment; S8. Install cable segment adapters (5) at both ends of the cable segment, assemble the cable segments through the cable segment connecting terminals (8) according to the length of the fireproof cable, and obtain a fireproof cable of target length.

9. The method for producing a flame-retardant Class A segmented armored fireproof cable according to claim 8, characterized in that: In S5, both ends of the conductor core (21) are exposed from the metal isolation frame (22) by 10 mm to 30 mm, and both ends of the conductor core (21) can be inserted into the cable segment connection terminal (8).

10. The method for producing a flame-retardant Class A segmented armored fireproof cable according to claim 8, characterized in that: In the above-mentioned S8, the cable segment adapter (5) of the cable segment is first inserted into the cable segment connection terminal (8), and then the first positioning magnetic attraction block (7) and the second positioning magnetic attraction block (10) are matched in position and magnetically attracted, so that the conductor core (21) is inserted into the electrical connection piece (9) of the cable segment connection terminal (8), and finally the cable segment adapter (5) and the cable segment connection terminal (8) are fastened by a fastener.

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