A flame-retardant Class A segmented armored fireproof cable and method

Abstract

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. The fireproof cable is composed of cable segments, cable segment adapters and cable segment connection terminals. During use, the length of the continuous metal armor layer is shortened, and the eddy current loss in the use scenario is reduced. The modular structure of the encapsulated wire core unit is adopted, so that the overall wire core structure is changed into multiple modular encapsulated wire core units. In this way, the bending stress received during use can be dispersed. At the same time, each conductor wire core has an independent metal isolation frame for shielding, reducing the influence of crosstalk. In terms of cable material selection, inorganic materials are used. By setting a metal isolation frame structure, it can be ensured that the cable is processed, the damage of the insulation 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 wire cores of the fireproof cable is not up to standard is solved.

Description

Technical Field

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

[0002] Armored cables consist of conductors of various materials enclosed in an insulating metal sheath, resulting in a flexible, solid structure. These cables include armored thermocouples, armored RTDs, armored heaters, and armored lead wires, and are primarily used in applications such as chemical engineering, metallurgy, machinery manufacturing, and power generation.

[0003] However, in some specific usage scenarios, there are stringent requirements on the flame retardant performance of armored cables, which are required to reach flame retardant grade A, that is, to meet the Class A standard of "Combustion test of cables and optical cables under flame conditions" in the GB / T18380-2008 test standard.

[0004] On the one hand, the existing armored fire-resistant cables contain some combustible materials or materials with low ignition points during production, which have a certain probability of burning in the event of a fire, making it difficult to ensure that the product meets the requirements of Class A combustion performance. At the same time, these cables contain organic materials, such as the Chinese patent with publication number CN114758829A, which discloses a highly cold-resistant special-shaped armored Central Asian cable containing polyvinyl chloride resin, DOP and DOS and other ingredients. After burning, it may produce toxic gases, 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, in which polyvinyl chloride, polyester plastic and other materials are also used in the layer structures such as the armor part and the lining part.

[0005] On the other hand, the Industry 4.0 scenario places higher demands on the performance of cables. First, industrial robots are often in high-risk safety environments, and cables need to have extremely high flame retardant properties to prevent the spread of fire and ensure the safety of personnel and equipment. Secondly, traditional cable structures use an overall packaging structure in design and production, that is, all conductor cores in the cable are protected as a whole by protective layers and armor layers. Although this reduces the cost of cable production, the stress during use is concentrated, and cracking is prone to occur 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 the industrial robot. In addition, the entire cable needs to be replaced in the event of accidental damage.

[0006] Third, in new energy scenarios such as photovoltaic power generation, cables are often required to withstand high temperatures, high voltages, and large currents. However, the cable design schemes disclosed in the existing literature mentioned above use a continuous metal armor structure, which may form a large closed loop during power transmission, and is prone to eddy currents and eddy current losses. Summary of the Invention

[0007] The purpose of the present invention is to provide a flame-retardant Class A segmented armored fireproof cable and method to address the above-mentioned problems.

[0008] The technical solution adopted by the present invention is as follows: a flame-retardant Class A segmented armored fireproof cable, comprising a cable segment, a cable segment adapter and a cable segment connecting terminal;

[0009] The cable segment contains more than two packaged wire core units, and adjacent packaged wire core units are independent of each other, and 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 packaged wire core unit is made of inorganic material.

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

[0013] The insulating layer is wrapped 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 comprises a positioning core, a protective layer and a twisted steel wire armor;

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

[0018] The protective layer is wrapped around the arc surface of the packaged wire core unit, and the positioning core and the packaged wire core unit are wrapped into a cylindrical structure;

[0019] The steel wire twisted armor is twisted 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 comprises 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 protrusion is provided on the outer periphery of the cable segment adapter, and the positioning protrusion is filled with a first positioning magnetic 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, and the cable segment connection terminal includes a connection positioning unit and a wire core connection unit;

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

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

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

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

[0030] The second positioning magnetic block group includes the same number of second positioning magnetic blocks as the first positioning magnetic blocks, and the second positioning magnetic blocks can be attracted to the first positioning magnetic blocks.

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

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

[0033] The first positioning magnetic block and the second positioning magnetic block are both cylindrical structures, and the outer peripheries of the first positioning magnetic block and the second positioning magnetic block are wrapped with a Permalloy shielding sheet.

[0034] The present application provides a method for producing a flame-retardant Class A segmented armored fireproof cable, which is used to produce the flame-retardant Class A segmented armored fireproof cable, comprising the following steps:

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

[0036] S2. Processing a metal isolation frame by extrusion molding based on the number of encapsulated core units used in the fire-resistant cable to be produced;

[0037] S3. The conductor single wires are twisted into a bundle to obtain conductor strands, and then the conductor strands are twisted to obtain a conductor core;

[0038] S4. The inorganic mineral mica tape is wrapped around the outer periphery of the conductor core to form an insulating layer;

[0039] S5. The conductor core with an insulating layer is pushed into the metal isolation frame, and the core filling layer is filled between the insulating layer and the metal isolation frame, and the encapsulated core unit is obtained;

[0040] S6. Select a certain number of encapsulated wire core units, surround them and set them around the positioning core, and the top of the encapsulated wire core unit abuts the positioning core, and then wrap the inorganic mineral mica tape around the curved surface of the encapsulated wire core unit to form a cylindrical unit to be armored;

[0041] S7. The steel wire is twisted in a double-layer, double-phase manner on the armored unit to form a twisted steel wire armor to obtain a cable segment;

[0042] S8. Install cable segment adapters at both ends of the cable segment, and assemble the cable segments using the cable segment connection terminals according to the length of the fireproof cable to obtain a fireproof cable of the target length.

[0043] Optionally, in S5, both ends of the conductor core are exposed from the metal isolation frame by 10 mm to 30 mm, and both ends of the conductor core can be inserted into the cable segment connection terminal.

[0044] Optionally, in S8, the cable segment adapter of the cable segment is first pushed into the cable segment connection terminal, and then the first positioning magnetic block and the second positioning magnetic block are adapted to each other and magnetically attracted, so that the conductor core is inserted into the electrical connection piece of the cable segment connection terminal, and finally the cable segment adapter is fastened to the cable segment connection terminal by fasteners.

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

[0046] 1. The design of segmented armored fireproof cable is adopted from two dimensions. One dimension is to use cable segments, cable segment adapters and cable segment connection terminals to form a fireproof cable, which shortens the length of the continuous metal armor layer during use and reduces the eddy current loss in the use scenario. The other dimension is to adopt a modular structure such as encapsulated core units, so that the overall core structure is transformed into multiple modular encapsulated core units. In this way, the bending stress received during use can be dispersed. At the same time, each conductor core has an independent metal isolation frame for shielding, reducing the impact of crosstalk.

[0047] 2. In terms of cable material selection, inorganic materials are used. By setting up a metal isolation frame structure, the cable can be ensured during processing, greatly reducing the damage to the insulation layer during the extrusion process, improving the insulation resistance of the cable, and solving the problem of substandard insulation resistance between cores of fire-resistant cables.

[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. The new material, double-phase high-temperature resistant stainless steel wire twisted layer, can ensure that the cable will not deform under 1200°C flame conditions and can effectively isolate the flame. At the same time, the twisted structure can improve the bending performance of the cable. The structure of the cable segment uses inorganic materials and does not contain toxins, so that the product meets the A-level combustion performance requirements and meets the non-toxic requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of the cable segment structure of a flame-retardant Class A segmented armored fire-resistant cable;

[0050] Figure 2 This is a flame-retardant Class A segmented armored fireproof cable and cable segment adapter connection diagram;

[0051] Figure 3 This is a schematic diagram of the cable segment connection terminal structure;

[0052] Figure 4 This is a schematic diagram of the overall connection of a flame-retardant Class A segmented armored fire-resistant cable;

[0053] Figure 5 This is a schematic diagram of the assembly of a flame-retardant Class A segmented armored fire-resistant cable.

[0054] In the picture:

[0055] 1 is the positioning core, 2 is the encapsulated wire core unit, 21 is the conductor wire core, 22 is the metal isolation frame, 23 is the wire core filling layer, 24 is the insulation layer, 3 is the protective layer, 4 is the twisted steel wire armor, 5 is the cable segment adapter, 6 is the positioning protrusion, 7 is the first positioning magnetic block, 8 is the cable segment connection terminal, 9 is the electrical connection piece, 10 is the second positioning magnetic block, 11 is the positioning ring platform, 12 is the connecting insulating tape, 13 is the insertion cavity, 14 is the first cable segment, 15 is the second cable segment, and 16 is the push groove. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0057] Therefore, 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 invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0058] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

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

[0060] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended only to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions 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 expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

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

[0063] 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;

[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 packaged wire core unit 2 is made of inorganic material.

[0066] The purpose of this design is to adopt the design of segmented armored fireproof cable from two dimensions. One dimension is to use cable segments, cable segment adapters and cable segment connection terminals to form a fireproof cable, which shortens the length of the continuous metal armor layer during use and reduces the eddy current loss in the use scenario. The other dimension is to adopt a modular structure such as encapsulated wire core units, so that the overall wire core structure is transformed into multiple modular encapsulated wire core units. In this way, the bending stress received during use can be dispersed and the impact of crosstalk can be reduced. At the same time, inorganic materials are used and do not contain toxins, so that the product meets the Class A combustion performance requirements and meets the non-toxic requirements.

[0067] Meanwhile, in this embodiment, the packaged 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 is wrapped 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 also includes a positioning core 1, a protective layer 3 and a stranded steel wire armor 4;

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

[0073] The protective layer 3 is wrapped around the arc surface of the packaged wire core unit 2, and the positioning core 1 and the packaged wire core unit 2 are wrapped into a cylindrical structure;

[0074] The steel wire twisted armor 4 is twisted and wrapped around the outer periphery of the protective layer 3 .

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

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

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

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

[0079] The purpose of this design is to use inorganic materials in the selection of cable materials. By setting up a metal isolation frame structure, it can ensure that the damage to the insulation layer during the extrusion process during cable processing is greatly reduced, the insulation resistance of the cable is improved, and the problem of substandard insulation resistance between cores of fire-resistant cables is solved. At the same time, the metal isolation frame encloses the conductor cores in it, which can offset most of the magnetic field effects and improve the stability of power transmission of the insulated cores. The new material, a two-phase high-temperature resistant stainless steel wire twisted layer, can ensure that the cable does not deform under 1200°C flame conditions and can effectively isolate the flame. At the same time, the twisted structure can improve the bending performance of the cable. The structure of the cable segment uses inorganic materials and does not contain toxins, so that the product meets the A-level combustion performance requirements and meets the non-toxic requirements.

[0080] The present embodiment provides a specific composition of a wire core filling layer, which comprises, in parts by weight, 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 constitute a compound system, and the two have different flame retardant temperature ranges and can complement each other, thereby covering a wider flame retardant temperature range. In the case of sudden combustion, the two decompose to release water vapor to further reduce the surface temperature of the material and the oxygen concentration.

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

[0082] The aluminum oxide is resistant to high temperatures and can form an AI-Zn-BO glass phase structure with zinc borate to enhance the overall thermal shock stability.

[0083] like Figure 2 As shown, this embodiment provides a specific structure of a cable segment adapter, wherein 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 block 7.

[0084] At the same time, if Figure 3 As shown, this embodiment provides a specific structure of a cable segment connection terminal, wherein the cable segment connection terminal 8 is a cylindrical structure, both ends of the cable segment connection terminal 8 can be inserted into the cable segment adapter 5, and the cable segment connection terminal 8 includes a connection positioning unit and a wire 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 connecting 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;

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

[0088] The positioning ring 11 is provided 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;

[0089] The second positioning magnetic block group includes the same number of second positioning magnetic blocks 10 as the first positioning magnetic blocks 7 , and the second positioning magnetic blocks 10 can be attracted to the first positioning magnetic blocks 7 .

[0090] Furthermore, 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] The first positioning magnetic block 7 and the second positioning magnetic block 10 are both cylindrical structures, and the outer peripheries of the first positioning magnetic block 7 and the second positioning magnetic block 10 are wrapped with a Permalloy shielding sheet.

[0093] The purpose of this design is that, since the technical solution provided in this embodiment adopts a cable structure assembled from multiple packaged wire core units, the position matching requirements of the conductor cores in each packaged wire core unit are more stringent. Therefore, in the process of setting up the cable segment adapter to assemble multiple cable segments, it is necessary to align the positions of the conductor cores. Therefore, a positioning magnetic block is used for assistance. In subsequent use, it is convenient for the cable segment adapter to align with the cable segment connection terminal, and it is also convenient for the assembler to quickly determine whether the cable segment adapter and the cable segment are compatible.

[0094] It should be pointed out that when the cable is used for simple power transmission, the magnetic field generated by the positioning magnetic block does not affect or significantly affect the power transmission, but when used as a signal transmission cable, it will have a certain impact. Therefore, in this embodiment, on the one hand, the positioning magnetic block is set away from the conductor core, and on the other hand, the Permalloy shielding sheet is wrapped to reduce the axial impact of the positioning magnetic block on the conductor core.

[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 is attenuated by about 70%, which can meet the needs of general industrial scenarios when matched with a Permalloy shielding sheet. Of course, when implementing this solution, technical personnel in this field can choose to add other active filtering to reduce magnetic field interference in existing structures when dealing with more demanding industrial scenarios, so as to further reduce magnetic field interference.

[0097] This embodiment provides a method for producing the flame-retardant Class A segmented armored fireproof cable of the above embodiment, comprising the following steps:

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

[0099] S2 based on the number of 2 encapsulated core units used in the production of fireproof cables, processed by extrusion metal isolation frame 22;

[0100] S3. The conductor single wires are twisted once to obtain conductor strands, and then the conductor strands are twisted to obtain a conductor core 21;

[0101] S4. The inorganic mineral mica tape is wrapped around the outer periphery of the conductor core 21 to form an insulating layer 24;

[0102] S5. The conductor core 21 with the insulating layer 24 is pushed into the metal isolation frame 22, and the core filling layer 23 is filled between the insulating layer 24 and the metal isolation frame 22, and the encapsulated core unit 2 is obtained;

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

[0104] S7. The steel wire is twisted in a double-layer, dual-phase manner on the armored unit to be formed to form a stranded steel wire armor 4 to obtain a cable segment;

[0105] S8. Install the cable segment adapters 5 at both ends of the cable segment, and assemble the cable segments through the cable segment connection terminals 8 according to the length of the fireproof cable to obtain a fireproof cable of the target length.

[0106] Furthermore, 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 .

[0107] Furthermore, in S8, the cable segment adapter 5 of the cable segment is first pushed into the cable segment connection terminal 8, and then the first positioning magnetic block 7 and the second positioning magnetic block 10 are adapted to each other 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 is fastened to the cable segment connection terminal 8 by fasteners.

[0108] In specific use, three, four or more encapsulated core units 2 are selected according to actual needs to form a segmented armored fireproof cable, such as Figure 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 are 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 connection terminal. After the cable segments are prepared in the above steps, their ends are inserted into the cable segment adapters and tightened, and at the same time, the conductor cores are passed through the cable segment adapters for extending into the cable segment connection terminals.

[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 relationship between the two through external fixing bolts or snap-on structures. Since this is existing technology, 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 conducted. It should be pointed out that the effect of 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 was selected in this test:

[0114] Select a cable segment with a length of 100 mm, ambient temperature: 23±2°C, 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 combustion test chamber.

[0119] step:

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

[0121] (2) Flame action time: After 10 seconds, remove the fire source and record the self-extinguishing time and the situation of dripping matter igniting the cotton pad;

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

[0123] The results showed that there was no combustion, no flame spread, and the cotton pad did not burn, meeting the Class A standard.

[0124] Based on the GB / T18380-2008 test standard, a bundled vertical combustion test is conducted:

[0125] Device: Bundle combustion test stand.

[0126] step:

[0127] (1) Apply open flame to the middle of the cable through an alcohol burner, with a flame height of 20-30mm, and continue burning for 20 minutes;

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

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

[0130] The results showed that there was no burning, no flame spread, no burning of the cotton pad, and the armor layer structure was intact, meeting Class A standards.

[0131] To perform gross calorific value measurements:

[0132] step:

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

[0134] (2) After ignition, the combustion is complete and the total heat release is recorded;

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

[0136] As a result, the PCS of the cable segment in this embodiment is 1.8 MJ / kg, while the typical value of traditional PVC cable is >15 MJ / kg.

[0137] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flame retardant Class A segmented armored fireproof cable, characterized in that: It includes 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 an inorganic material, and 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 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.

2. A flame-retardant Class A segmented armored fireproof cable according to claim 1, 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) abuts against the positioning core (1); The protective layer (3) is wrapped around 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).

3. The flame-retardant Class A segmented armored fireproof cable according to claim 2, characterized in that: The protective layer (3) is wrapped with an inorganic mineral mica tape; The 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.

4. The flame-retardant Class A segmented armored fireproof cable according to claim 1, 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 block (7).

5. The flame-retardant Class A segmented armored fireproof cable according to claim 4, 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) includes a connection positioning unit and a wire core connection unit. The wire core connection unit comprises an electrical connection piece (9) and a connection insulating tape (12); The electrical connection piece (9) is arranged in the connecting 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 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 block group includes second positioning magnetic blocks (10) whose number is equal to that of the first positioning magnetic blocks (7), and the second positioning magnetic blocks (10) can be attracted to the first positioning magnetic blocks (7).

6. The flame-retardant Class A segmented armored fireproof cable according to claim 5, 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 block (7) and the second positioning magnetic block (10) are both cylindrical structures, and the outer peripheries of the first positioning magnetic block (7) and the second positioning magnetic block (10) are wrapped with a Permalloy shielding sheet.

7. A method for producing a flame-retardant Class A segmented armored fireproof cable, for producing a flame-retardant Class A segmented armored fireproof cable according to claim 5 or 6, 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 into a bundle 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 them and arrange them around the positioning core (1), and make the top of the encapsulated wire core unit (2) abut against the positioning core (1), and then wrap the inorganic mineral mica tape around the arc surface of the encapsulated wire core unit (2) to form a cylindrical unit to be armored; S7. twisting the steel wires in a double-layer, 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.

8. The method for producing a flame-retardant Class A segmented armored fireproof cable according to claim 7, characterized in that: In the S5, both ends of the conductor core (21) are exposed 10 mm to 30 mm from the metal isolation frame (22), and both ends of the conductor core (21) can be inserted into the cable segment connection terminal (8).

9. The method for producing a flame-retardant Class A segmented armored fireproof cable according to claim 7, characterized in that: In the above-mentioned S8, the cable segment adapter (5) of the cable segment is first pushed into the cable segment connection terminal (8), and then the first positioning magnetic block (7) and the second positioning magnetic block (10) are adapted to each other 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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