Self-bearing braided shielding medium-voltage overhead insulated cable

Abstract

The invention relates to the technical field of cables, in particular to a self-bearing braided shielding medium-voltage overhead insulated cable, which comprises a wire core and a wrapping layer, and is characterized in that an elastic supporting belt is wound on the periphery of the wire core and comprises a plurality of inward contraction belts and a plurality of outward expansion belts which are spliced together; the plurality of internal contraction bands and the plurality of external expansion bands are alternately distributed along the length extension direction of the wire core, two ends of each external expansion band are respectively and fixedly connected with one ends of two adjacent internal contraction bands, the internal contraction bands and the external expansion bands are respectively bent to be circular after being wound outside the wire core, and the internal contraction bands are fitted with the periphery of the wire core. The external expansion belt is eccentrically arranged on the periphery of the cable core, a gap is formed between the external expansion belt and the outer wall of the cable core, the two ends of the external expansion belt have the acting force expanding outwards, and the outer side of the external expansion belt is attached to the inner side of the wrapping layer in a supporting mode. The technical problem that in the prior art, cable bending easily causes mutual extrusion between internal cable cores, and the cable cores are damaged and deformed due to pressing is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a self-supporting braided shielded medium-voltage overhead insulated cable. Background Art

[0002] There are two main types of three-core medium-voltage overhead insulated cables currently on the market. The first consists of three single-core overhead insulated cables twisted together without a metallic shield. The second consists of three single-core power cables twisted together with a carrier wire for use in overhead applications. The second structure uses a copper wire shield, which homogenizes the magnetic field and provides short-circuit protection. The outer sheath also ensures good electrical insulation performance, making it more widely used in the current market. However, since this type of cable has a certain amount of bending in its fixed installation position, the cable cannot release this bending force, which can easily cause the internal cores to squeeze each other, resulting in core pressure loss and deformation. Summary of the Invention

[0003] In order to overcome the shortcomings of the existing technology, the present invention proposes a self-supporting braided shielded medium-voltage overhead insulated cable to solve the technical problem in the existing technology that bending of the cable easily causes the internal cores to squeeze each other, resulting in pressure loss and deformation of the cores.

[0004] The self-supporting braided shielded medium-voltage overhead insulated cable of the present invention adopts the following technical solution: A self-supporting braided shielded medium-voltage overhead insulated cable comprises a plurality of cores and a wrapping layer wrapped around the periphery of the plurality of cores, an elastic support band being wrapped around the periphery of each core, the elastic support band being spirally wrapped around the periphery of the core along the length extension direction of the core, the elastic support band comprising a plurality of inner shrinking bands and a plurality of outer expansion bands spliced together, the plurality of inner shrinking bands and the plurality of outer expansion bands being alternately distributed along the length extension direction of the core, the two ends of each outer expansion band being fixedly connected to one end of two adjacent inner shrinking bands, the inner shrinking band and the outer expansion band being bent into a circle after being wound around the outside of the core, the inner shrinking band being in conformity with the periphery of the core, the outer diameter of the outer expansion band being larger than the outer diameter of the inner shrinking band, and the outer expansion band being eccentrically arranged on the periphery of the core, a gap being provided between the outer expansion band and the outer wall of the core, the two ends of the outer expansion band having a force to expand outwards, and the outer side of the outer expansion band being in conformity with the inner support of the wrapping layer.

[0005] Furthermore, there are three wire cores, which are distributed in an equilateral triangle, and a supporting frame is provided between the three wire cores.

[0006] Furthermore, the support skeleton includes a support core located in the center of the self-supporting braided shielded medium voltage overhead insulated cable, and also includes a plurality of support arms integrally connected to the support core, the support arms including a first support arm, a second support arm and a third support arm, the first support arm, the second support arm and the third support arm are evenly spaced along the circumference of the support core, and the first support arm, the second support arm and the third support arm are respectively located between two adjacent cores.

[0007] Furthermore, the first support arm, the second support arm and the third support arm have the same structure. The first support arm, the second support arm and the third support arm respectively include a lower arc plate and two side arc plates. One end of the two side arc plates is connected to the same position of the support core so that the two side arc plates are in a herringbone shape. The two ends of the lower arc plate are respectively connected to the ends of the two side arc plates away from the support core. The two side arc plates and one lower arc plate form a triangular support structure.

[0008] Furthermore, the concave surfaces of the two side arc plates of each support arm are arranged back to back, and the concave surfaces of the two side arc plates are respectively fitted with the outer sides of the outer expansion bands of the adjacent wire cores. The concave surface of the lower arc plate faces away from the support core, and the two ends of the lower arc plate are respectively supported and cooperated with the inner wall of the wrapping layer around the three wire cores.

[0009] Furthermore, the first support arm, the second support arm and the third support arm are respectively arranged in plurality along the length extension direction of the wire core, and the side arc plates of each first support arm, the second support arm and the third support arm are respectively fitted with the outer support of the outer expansion band outside the wire core.

[0010] Furthermore, the supporting frame is made of insulating and heat-insulating material.

[0011] Furthermore, the inner shrinking band and the outer expanding band are both made of insulating heat-conducting materials, and both the inner shrinking band and the outer expanding band are elastic.

[0012] Furthermore, the wrapping layer includes a braided shielding layer, a polyester layer and an outer protective layer which are sequentially arranged from the inside to the outside.

[0013] Furthermore, each wire core includes an internal conductor, and also includes an inner shielding layer, an insulating layer and an outer insulating shielding layer sequentially wrapped around the outer periphery of the conductor.

[0014] The beneficial effects of the present invention are as follows: a self-supporting braided shielded medium-voltage overhead insulated cable is constructed by wrapping an elastic support band around the periphery of each core, the elastic support band being composed of segmented inner shrinking bands and outer expansion bands. The outer expansion band has an outward expansion force, while the inner shrinking band has an inward contraction force. When the outer expansion band and the inner shrinking band are connected together and wrapped around the outer core, the outward expansion force and the inward contraction force can offset each other. The elastic support band is located around the outer core and supported within the sheathing layer. When the self-supporting braided shielded medium-voltage overhead insulated cable is squeezed or bent, the outer sheathing layer is compressed to squeeze the outer expansion band around the core. The outer expansion band shrinks inward after being compressed, and then drives the inner shrinking band to expand outward to overcome its own inward contraction force. In this way, space is created around the outer periphery of the multiple cores for the cores to move relative to each other, and the multiple cores are prevented from being squeezed by each other, thus avoiding damage to the cores caused by bending and squeezing.

[0015] Furthermore, by setting a support frame with a special structure between the three wire cores, the support arm of the support frame can support the inner side of the wrapping layer, and the arc plate fits with the outer expansion band on the outside of the cable, thereby supporting the wrapping layer and limiting the relative positions of the three wire cores. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0017] Figure 1 It is a cross-sectional schematic diagram of an embodiment of a self-supporting braided shield medium voltage overhead insulated cable of the present invention; Figure 2 A schematic diagram of an embodiment of a self-supporting braided shielded medium-voltage overhead insulated cable according to the present invention, in which an elastic support belt is wrapped around the outer periphery of the insulation layer (only a portion of the length is shown); Figure 3 This is a cross-sectional schematic diagram of an embodiment of a self-supporting braided shielded medium-voltage overhead insulated cable of the present invention, in which an elastic support belt is wrapped around the outer periphery of the insulation layer.

[0018] In the figure: 1. Conductor; 2. Inner shielding layer; 3. Insulating layer; 4. Outer insulating shielding layer; 5. Braided shielding layer; 6. Polyester layer; 7. Outer sheath; 8. Support frame; 81. Lower arc plate; 82. Side arc plate; 83. Support core; 84. First support arm; 85. Second support arm; 86. Third support arm; 9. Elastic support band; 91. Inward shrinking band; 92. Outward expanding band. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] An embodiment of a self-supporting braided shielded medium voltage overhead insulated cable according to the present invention is as follows: Figures 1 to 3 As shown, the self-supporting braided shielded medium-voltage overhead insulated cable includes multiple cores and a sheathing layer wrapped around the cores. In this embodiment, the sheathing layer includes a braided shielding layer 5, a polyester layer 6, and an outer sheath 7, arranged sequentially from the inside out. Each core includes an internal conductor 1, and also includes an inner shielding layer 2, an insulating layer 3, and an outer insulating shielding layer 4, which are sequentially wrapped around the conductor 1. In this embodiment, the conductor 1 is an aluminum wire, the insulating layer 3 is a TR-XLPE insulating layer, the outer sheath 7 is an LDPE outer sheath, and the braided shielding layer 5 is a tinned copper wire braid.

[0021] In the present invention, there are three cores, which are arranged in an equilateral triangle. The outer periphery of each core is wrapped with an elastic support band 9, which is spirally wound around the outer periphery of the core along the length extension direction of the core. The elastic support band 9 includes a plurality of inner shrinking bands 91 and a plurality of outer expansion bands 92 spliced together. The plurality of inner shrinking bands 91 and the plurality of outer expansion bands 92 are alternately distributed along the length extension direction of the core, and the two ends of each outer expansion band 92 are fixedly connected to one end of two adjacent inner shrinking bands 91. The inner shrinking band 91 and the outer expansion band 92 are respectively bent into a circle after being wrapped around the outside of the wire core. Both the inner shrinking band 91 and the outer expansion band 92 can be bent and deformed along the radial direction of the wire core, wherein the inner shrinking band 91 has an inner shrinking force that shrinks inward along the radial direction of the wire core, and the outer expansion band 92 has an expansion force that expands outward along the radial direction of the wire core. The inner shrinking band 91 fits closely with the outer circumference of the wire core, the outer diameter of the outer expansion band 92 is larger than the outer diameter of the inner shrinking band 91, and the outer expansion band 92 is eccentrically arranged on the periphery of the wire core. There is a gap between the outer expansion band 92 and the outer wall of the wire core, and both ends of the outer expansion band 92 have a force to expand outward. Since the outer expansion band 92 has an outward expansion force, and the inner shrinking band 91 has an inward contraction force, after the outer expansion band 92 and the inner shrinking band 91 are connected together and wrapped around the wire core, when the insulated cable is not squeezed or bent, the outward expansion force and the inward contraction force can offset each other. At this time, the expansion force of the outer expansion band 92 is basically equal to the inward contraction force of the inner shrinking band 91, and the outer expansion band 92 and the inner shrinking band 91 are in a balanced state. Figure 2The state shown. The gap between the inner side of the outer expansion band 92 and the core is located on the side of the core close to the inner wall of the wrapping layer, so that the outer side of the outer expansion band 92 is supported and fitted with the inner side of the wrapping layer, and the elastic support band 9 is located on the periphery of the core and supported inside the wrapping layer. When the self-supporting braided shielded medium-voltage overhead insulated cable is squeezed or bent, the outer wrapping layer is compressed to squeeze the outer expansion band 92 on the periphery of the core. The outer expansion band 92 will shrink inward after being compressed, thus breaking the equilibrium state formed between the outer expansion band 92 and the inner shrinking band 91, and then driving the inner shrinking band 91 to overcome its own inward shrinkage force and expand outward. In this way, space will appear on the periphery of the three cores for the relative movement of the three cores, and there will be no mutual squeezing between the three cores, avoiding bending and squeezing to cause damage to the core.

[0022] In this embodiment, to better constrain and secure the positions of the three wire cores, a support frame 8 is provided between the three wire cores. Multiple support frames 8 are spaced apart along the extension direction of the wire cores, and the dimensions of the support frames 8 along the extension direction of the wire cores are smaller than the spacing between two adjacent support frames 8. The support frame 8 includes a support core 83 located at the center of the self-supporting braided shielded medium-voltage overhead insulated cable, and multiple support arms integrally connected to the support core 83. The multiple support arms include a first support arm 84, a second support arm 85, and a third support arm 86. The first, second, and third support arms 84, 85, 86 are evenly spaced along the circumference of the support core 83 and are respectively located between two adjacent wire cores. The first, second, and third support arms 84, 85, 86 have identical structures, each including a lower arc plate 81 and two side arc plates 82.

[0023] In this embodiment, one end of the two side arc plates 82 is connected to the same position of the support core 83 so that the two side arc plates 82 are in a herringbone shape. The two ends of the lower arc plate 81 are respectively connected to the ends of the two side arc plates 82 away from the support core 83, and the two side arc plates 82 and the lower arc plate 81 form a triangular support structure. The concave surfaces of the two side arc plates 82 of each support arm are arranged back to back, and the concave surfaces of the two side arc plates 82 are respectively fitted with the outer sides of the outer expansion bands 92 of the adjacent wire cores. The concave surface of the lower arc plate 81 faces away from the support core 83, and the two ends of the lower arc plate 81 are respectively supported and matched with the inner wall of the outer wrapping layer of the three wire cores. In this embodiment, the support skeleton 8 is made of insulating and heat-insulating material, and each side arc plate 82 and each lower arc plate 81 have a certain elastic deformation ability, so that an elastic support is formed between the arc plate and the inner wall of the outer wrapping layer, which plays a stable supporting role.

[0024] In this embodiment, the first support arm 84, the second support arm 85 and the third support arm 86 are respectively arranged at intervals along the length extension direction of the wire core, and the side arc plate 82 of each first support arm 84, the second support arm 85 and the third support arm 86 is respectively in contact with the outer support of the outer expansion band 92 on the periphery of the wire core.

[0025] In this embodiment, the inner shrinking band 91 and the outer expanding band 92 of the elastic support band 9 are both made of insulating and thermally conductive materials, and both are elastic. The outer expanding band 92 of the elastic support band 9 is in contact with the inner side of the wrapping layer, so that the outer expanding band 92 can conduct heat from the outer periphery of the wire core to the wrapping layer, thereby improving the heat dissipation efficiency of the wire core.

[0026] In the present invention, the material of the elastic support belt 9 can be silicone rubber, polyurethane, thermally conductive rubber, boron nitride filled polymer material, graphene filled material, fluororubber, polyimide, thermally conductive silicone, thermally conductive ceramic material, polyester elastomer.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 self-supporting braided shielded medium voltage overhead insulated cable, comprising a plurality of cores and a sheathing layer wrapped around the plurality of cores, characterized in that: An elastic support band (9) is wound around the periphery of each wire core, and the elastic support band (9) is spirally wound around the periphery of the wire core along the length extension direction of the wire core. The elastic support band (9) includes a plurality of inner shrinking bands (91) and a plurality of outer expansion bands (92) spliced together. The plurality of inner shrinking bands (91) and the plurality of outer expansion bands (92) are alternately distributed along the length extension direction of the wire core, and the two ends of each outer expansion band (92) are fixedly connected to one end of two adjacent inner shrinking bands (91). The inner shrinking band The (91) and the outer expansion band (92) are respectively bent into a circle after being wound around the outside of the wire core. The inner shrinking band (91) fits in with the outer periphery of the wire core. The outer diameter of the outer expansion band (92) is larger than the outer diameter of the inner shrinking band (91), and the outer expansion band (92) is eccentrically arranged on the periphery of the wire core. There is a gap between the outer expansion band (92) and the outer wall of the wire core. Both ends of the outer expansion band (92) have an outward expansion force, and the outer side of the outer expansion band (92) fits in with the inner support of the wrapping layer.

2. The self-supporting braided shielded medium voltage overhead insulated cable according to claim 1, characterized in that: There are three wire cores, which are distributed in an equilateral triangle, and a supporting frame (8) is provided between the three wire cores.

3. The self-supporting braided shield medium voltage overhead insulated cable according to claim 2, characterized in that: The support skeleton (8) includes a support core (83) located at the center of the self-supporting braided shielded medium-voltage overhead insulated cable, and also includes a plurality of support arms integrally connected to the support core (83), the support arms including a first support arm (84), a second support arm (85) and a third support arm (86), the first support arm (84), the second support arm (85) and the third support arm (86) are evenly spaced along the circumference of the support core (83), and the first support arm (84), the second support arm (85) and the third support arm (86) are respectively located between two adjacent cores.

4. The self-supporting braided shield medium voltage overhead insulated cable according to claim 3, characterized in that: The first support arm (84), the second support arm (85) and the third support arm (86) have the same structure. The first support arm (84), the second support arm (85) and the third support arm (86) respectively include a lower arc plate (81) and two side arc plates (82). One end of the two side arc plates (82) is connected to the same position of the support core (83) so that the two side arc plates (82) are in a herringbone shape. The two ends of the lower arc plate (81) are respectively connected to one end of the two side arc plates (82) away from the support core (83). The two side arc plates (82) and the lower arc plate (81) form a triangular support structure.

5. The self-supporting braided shield medium voltage overhead insulated cable according to claim 4, characterized in that: The concave surfaces of the two side arc plates (82) of each support arm are arranged back to back, and the concave surfaces of the two side arc plates (82) are respectively fitted with the outer sides of the outer expansion bands (92) around the adjacent wire cores, and the concave surface of the lower arc plate (81) faces away from the support core (83), and the two ends of the lower arc plate (81) are respectively supported and matched with the inner wall of the wrapping layer around the three wire cores.

6. The self-supporting braided shield medium voltage overhead insulated cable according to claim 5, characterized in that: A plurality of the first support arms (84), the second support arms (85) and the third support arms (86) are respectively arranged at intervals along the length extension direction of the wire core, and the side arc plates (82) of each first support arm (84), the second support arm (85) and the third support arm (86) are respectively supported and fitted with the outer side of the outer expansion band (92) on the outer periphery of the wire core.

7. The self-supporting braided shield medium voltage overhead insulated cable according to claim 6, characterized in that: The supporting frame (8) is made of insulating and heat-insulating material.

8. The self-supporting braided shield medium voltage overhead insulated cable according to any one of claims 1 to 7, characterized in that: The inner shrinking band (91) and the outer expanding band (92) are both made of insulating heat-conducting materials, and both the inner shrinking band (91) and the outer expanding band (92) are elastic.

9. The self-supporting braided shield medium voltage overhead insulated cable according to claim 8, characterized in that: The wrapping layer comprises a braided shielding layer (5), a polyester layer (6) and an outer protective layer (7) which are arranged in sequence from the inside to the outside.

10. The self-supporting braided shield medium voltage overhead insulated cable according to claim 9, characterized in that: Each wire core comprises an inner conductor (1), an inner shielding layer (2), an insulating layer (3) and an outer insulating shielding layer (4) which are sequentially wrapped around the outer periphery of the conductor (1).

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