Large-cross-section heat-insulation fireproof inner sheath cable

Abstract

The utility model belongs to the technical field of cables, and particularly relates to a large-cross-section heat-insulation fireproof inner sheath cable, which comprises a cable body, conductor wire cores and an insulating layer coated outside the conductor wire cores are arranged in the cable body, an inner sheath is arranged outside the insulating layer, reinforcing ribs are arranged in the inner sheath, and the reinforcing ribs are arranged in the inner sheath. A shielding layer and an outer sheath are sequentially coated and molded outside the inner sheath; it can be understood that the inner sheath is formed by embedding the silica gel expanded graphite heat dissipation strips and the ceramic silicone rubber fireproof strips, and the cable has fire resistance, heat insulation and structural stability. At normal temperature, the heat dissipation strips effectively guide out the heat of the wire core, and the fireproof strips maintain the flexibility of the cable. At high temperature, the heat dissipation strips expand to form porous carbon layers for oxygen resistance and flame suppression, the fireproof strips are sintered to form porous ceramic layers for isolating fire, and both the heat dissipation strips and the fireproof strips have low-smoke and non-toxic characteristics; the additional arrangement of the reinforcing ribs further improves the cable strength and avoids line collapse.

Description

Technical Field

[0001] This utility model belongs to the field of cable technology, and in particular relates to a large-section heat-insulating and fire-resistant inner sheath cable. Background Technology

[0002] Large-section inner-sheathed cables are special cables used in high-voltage, high-current transmission scenarios. Their technological development stems from the increasing demand in power systems for high-capacity, high-reliability power transmission. Traditional cables are prone to failure under high-voltage, high-current conditions due to conductor overheating, mechanical stress, or insulation aging. The introduction of inner-sheath technology, by adding a high-mechanical-strength, high-temperature-resistant sheath (such as lead alloy, aluminum-plastic composite tape, or flame-retardant polymer) between the conductor and the outer sheath, significantly improves the cable's mechanical protection, radial waterproofing, and electromagnetic interference resistance.

[0003] The existing mica tape wound insulation and fireproof cable has a mica tape wound structure that becomes brittle and easily falls off at high temperatures, resulting in unstable fire resistance. The process is also complex and prone to defects. In addition, some of the cables contain harmful substances such as asbestos, which does not meet modern environmental protection requirements. Furthermore, the multi-layer wound process is complex, has low production efficiency, and a high defect rate. Magnesium oxide mineral cables are resistant to high temperatures, but they are difficult to install and require special installation processes, resulting in high labor and material costs.

[0004] To address the aforementioned issues, this application proposes a large-section heat-insulating and fire-resistant inner-sheathed cable. Utility Model Content

[0005] The purpose of this utility model is to provide a large-section heat-insulating and fire-resistant inner sheathed cable, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0007] This utility model is a large cross-section heat-insulating and fireproof inner sheath cable, including a cable body, inside which there is a conductor core and an insulation layer covering the conductor core, an inner sheath outside the insulation layer, a reinforcing rib in the inner sheath, and a shielding layer and an outer sheath sequentially covering the outer side of the inner sheath.

[0008] The inner sheath includes an inner heat dissipation strip and an outer fireproof strip. The heat dissipation strip and the fireproof strip are composed of multiple circumferentially distributed strips. The circumferentially distributed heat dissipation strip and the fireproof strip are staggered. The reinforcing rib is located at the connection of two adjacent heat dissipation strips. The heat dissipation strip is formed by silicone expanded graphite, and the fireproof strip is formed by ceramicized silicone rubber.

[0009] Furthermore, symmetrical fitting grooves are formed on both sides of the heat dissipation strip, and the fitting grooves between two adjacent heat dissipation strips form a strip-shaped groove that is interference-fitted with the fitting strip. The circumferentially distributed heat dissipation strips are positioned by interference fit with the fireproof strip.

[0010] Furthermore, symmetrical embedding grooves are formed on both sides of the heat dissipation strip, and the embedding groove between two adjacent heat dissipation strips forms a space for accommodating the reinforcing rib. The heat dissipation strip and the fireproof strip wrap around the reinforcing rib.

[0011] Furthermore, the inner side of the heat dissipation strip has an arc-shaped surface that matches the outer side of the insulation layer, and multiple heat dissipation strips arranged circumferentially combine to wrap the insulation layer.

[0012] Furthermore, symmetrically arranged buffer grooves are formed on the outer side of the heat dissipation strip, and the buffer grooves are circumferentially staggered from the reinforcing ribs.

[0013] Furthermore, both the heat dissipation strip and the fireproof strip are extruded.

[0014] This utility model has the following beneficial effects:

[0015] In this invention, the heat dissipation strip composed of silicone expanded graphite can effectively dissipate heat for the conductor core at room temperature. Under high temperature, it will expand rapidly to form a worm-like porous carbon layer, which isolates oxygen and inhibits the spread of flame. Furthermore, the expanded graphite has excellent heat resistance, providing protection for the conductor core, while the silicone can ensure the flexibility and insulation of the cable.

[0016] In this invention, the fireproof strip composed of ceramicized silicone rubber can ensure the elasticity and toughness of the cable at room temperature by utilizing the properties of silicone. It is sintered into a porous ceramic layer at high temperature to isolate flames and heat, ensuring the safety and reliability of the wire core. Moreover, the ceramicized silicone rubber has low smoke density and no toxic gas release when burning. Even after ceramicization, it still has a certain impact resistance to prevent the line from collapsing.

[0017] In summary, the inner sheath composed of expanded graphite and ceramicized silicone rubber has the advantages of good fire resistance and heat insulation. At the same time, the production method of using heat dissipation strips and fireproof strips is simpler, and the reinforcing ribs added between the two provide strength to the cable and ensure stable use.

[0018] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall appearance structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the cross-section of the present invention;

[0022] Figure 3 This is a partially enlarged structural diagram of the heat sink.

[0023] Figure 4 This is a partially enlarged structural diagram of the fireproof strip;

[0024] The attached diagram lists the components represented by each number as follows:

[0025] In the diagram: 1. Body; 2. Conductor core; 3. Insulation layer; 4. Heat dissipation strip; 41. Arc-shaped surface; 42. Fitting groove; 43. Embedded groove; 44. Buffer groove; 5. Reinforcing rib; 6. Fireproof strip; 61. Fitting strip; 7. Shielding layer; 8. Outer sheath. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around" and other terms indicating orientation or positional relationship are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] Please see Figure 1 - Figure 4 As shown, this utility model is a large cross-section heat-insulating and fireproof inner sheath cable, including a cable body 1, a conductor core 2 inside the body 1 and an insulation layer 3 covering the conductor core 2, an inner sheath outside the insulation layer 3, a reinforcing rib 5 in the inner sheath, and a shielding layer 7 and an outer sheath 8 sequentially wrapped around the outer side of the inner sheath.

[0029] The inner sheath includes an inner heat dissipation strip 4 and an outer fireproof strip 6. The shielding layer 7 covers the outside of the fireproof strip 6. Both the heat dissipation strip 4 and the fireproof strip 6 are multiple strips distributed circumferentially to form the sheath. The circumferentially distributed heat dissipation strip 4 and fireproof strip 6 are staggered. The staggered fireproof strip 6 can effectively block the connection between adjacent heat dissipation strips 4, preventing flames from entering through the gaps between the joints. This facilitates production while ensuring reliability. The reinforcing rib 5 is located at the connection between two adjacent heat dissipation strips 4. The heat dissipation strip 4 is made of silicone expanded graphite, and the fireproof strip 6 is made of ceramicized silicone rubber.

[0030] Among them, symmetrical fitting grooves 42 are formed on both sides of the heat dissipation strip 4. The fitting grooves 42 between two adjacent heat dissipation strips 4 form a strip groove that is interference-fitted with the fitting strip 61. The circumferentially distributed heat dissipation strips 4 are positioned by interference fit with the fireproof strip 6. The heat dissipation strip 4, the reinforcing rib 5, and the fireproof strip 6 can be integrated by the fit between the fitting groove 42 and the fitting strip 61. In actual production, the shielding layer 7 and the outer sheath 8 can be directly wrapped on the outside without the need for external support, which improves the structural stability and facilitates production.

[0031] Among them, symmetrical embedding grooves 43 are formed on both sides of the heat dissipation strip 4, and the embedding grooves 43 between two adjacent heat dissipation strips 4 form a space for the reinforcing rib 5. The heat dissipation strip 4 and the fireproof strip 6 wrap around the reinforcing rib 5.

[0032] The heat dissipation strip 4 has an arc-shaped surface 41 that matches the outside of the insulation layer 3. Multiple heat dissipation strips 4 arranged around the circumference combine to wrap the insulation layer 3. The fit between the arc-shaped surface 41 and the insulation layer 3 facilitates the assembly between the heat dissipation strip 4 and the insulation layer 3, ensuring the compactness of the two after assembly.

[0033] Among them, the heat dissipation strip 4 has symmetrically arranged buffer grooves 44 on the outer side. The buffer grooves 44 and the reinforcing ribs 5 are distributed in a staggered manner around the circumference, which combines buffering and reinforcement in a staggered manner, and can ensure the strength while ensuring the toughness of the cable.

[0034] Among them, heat dissipation strip 4 and fireproof strip 6 are both extruded. Extrusion molding can be carried out simultaneously with the coating of insulation layer 3, which improves production efficiency. Moreover, the extruded strip shape is easy to assemble into cables, reducing the difficulty of the process.

[0035] Understandably, this utility model uses a silicone expanded graphite heat dissipation strip and a ceramicized silicone rubber fireproof strip to form an inner sheath, which combines fire resistance, heat insulation, and structural stability. At room temperature, the heat dissipation strip effectively dissipates heat from the wire core, while the fireproof strip maintains the cable's flexibility. At high temperatures, the heat dissipation strip expands to form a porous carbon layer that blocks oxygen and suppresses flames, while the fireproof strip sinters into a porous ceramic layer that isolates the fire. Both have low smoke and non-toxic properties. The addition of reinforcing ribs further enhances the cable's strength and prevents the line from collapsing.

[0036] One specific application of this embodiment is:

[0037] Molding of Heat Dissipation Strip 4: Raw material pretreatment (drying expanded graphite, preparing silica gel base material), mixing (uniformly dispersing graphite and additives in an internal mixer), filtration and impurity removal, extrusion molding (forming rubber strips using a segmented temperature-controlled extruder), vulcanization and setting (crosslinking and curing in hot air or a continuous vulcanizing furnace), cooling and performance testing, ultimately forming a cross-section as shown in the image. Figure 3 Heat sink 4 is shown;

[0038] The molding process of fireproof strip 6 involves: raw material mixing (uniformly mixing silicone rubber raw material, ceramic filler, flame retardant, crosslinking agent, etc. using an internal mixer or open mill), extrusion molding (extrudeing the compound into strips of the required cross-sectional shape using an extruder), vulcanization and setting (using a high-temperature vulcanization process to crosslink and cure the strips, typically at 150~200°C), cooling and finishing (removing burrs and cooling for setting), and performance testing (testing fire resistance, mechanical properties, etc.), ultimately forming a cross-section as shown in the image. Figure 4 Fireproof strip 6 is shown.

[0039] Production of Body 1: Insulation layer 3 is wrapped around conductor core 2. At the same time, heat dissipation strip 4 and fireproof strip 6 are formed by extrusion. Then, the arc-shaped surface 41 on the three heat dissipation strips 4 is attached to the outside of insulation layer 3 to form a complete sheath. Then, reinforcing rib 5 is placed in the embedding groove 43. Then, the interlocking strip 61 on the inside of the fireproof strip 6 is embedded in the interlocking groove 42. The fireproof strip 6 forms a complete sheath along the circumference. At this time, heat dissipation strip 4, reinforcing rib 5, and fireproof strip 6 are positioned as a whole. Then, shielding layer 7 and outer sheath 8 are wrapped around the outside of fireproof strip 6 to form a complete body 1.

[0040] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A large cross-section thermally and fire insulated inner protective jacketed cable comprising a cable body (1), characterized in that: The body (1) is internally provided with a conductor core (2) and an insulating layer (3) covering the conductor core (2) externally, the insulating layer (3) is externally provided with an inner sheath, the inner sheath is provided with a reinforcing rib (5), and the inner sheath is externally covered and formed with a shielding layer (7) and an outer sheath (8) in sequence; The inner sheath comprises heat dissipation strips (4) on the inner side and fireproof strips (6) on the outer side, the heat dissipation strips (4) and the fireproof strips (6) are both circumferentially distributed and form the sheath, the circumferentially distributed heat dissipation strips (4) and the fireproof strips (6) are arranged in a staggered manner, the reinforcing rib (5) is located at the connection of two adjacent heat dissipation strips (4), the heat dissipation strips (4) are formed of silica gel expanded graphite, and the fireproof strips (6) are formed of ceramicized silicone rubber.

2. A large cross-section, fire resistant, jacketed cable of claim 1, characterized in that: The heat dissipation strips (4) are formed with symmetrical fitting grooves (42) on both sides, the fitting grooves (42) between two adjacent heat dissipation strips (4) form strip-shaped grooves in interference fit with the fitting strips (61), and the circumferentially distributed heat dissipation strips (4) are positioned through the interference fit with the fireproof strips (6).

3. A large cross-section, fire resistant, jacketed cable of claim 1, characterized in that: The heat dissipation strips (4) are formed with symmetrical embedding grooves (43) on both sides, the embedding grooves (43) between two adjacent heat dissipation strips (4) form a containing space for the reinforcing rib (5), and the heat dissipation strips (4) and the fireproof strips (6) wrap the reinforcing rib (5).

4. A large cross-section, fire resistant, jacketed cable of claim 1, wherein: The heat dissipation strips (4) are formed with arc-shaped surfaces (41) on the inner side, which are in conformity with the outer part of the insulating layer (3), and the circumferentially arranged heat dissipation strips (4) wrap the insulating layer (3).

5. A large cross-section thermally insulated fire resistant inner sheath cable according to claim 1, characterized in that: The heat dissipation strips (4) are formed with symmetrical buffer grooves (44) on the outer side, and the buffer grooves (44) and the reinforcing rib (5) are circumferentially staggered.

6. A large cross-section thermally insulated fire resistant inner sheath cable according to claim 1, characterized in that: The heat dissipation strips (4) and the fireproof strips (6) are both extrusion formed.

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