A pre-branching cable external protection structure

Abstract

The utility model belongs to the technical field of power cable protection, especially a kind of pre-branch cable external protection structure, including upper half casing and lower half casing, the both ends of upper half casing and lower half casing are equipped with locking unit;Locking unit includes wedge half ring and conical half ring, wedge half ring inner wall is fixedly connected with baffle ring, the outer end of baffle ring is equipped with first counterbore, the outer end of conical half ring is equipped with the second counterbore corresponding with first counterbore, and pre-tight spring is equipped in second counterbore;Axial gap is equipped between conical half ring and wedge half ring, and outer taper surface and inner taper surface form matching taper;Protection cavity and locking assembly are formed by buckling connection, the external protection of pre-branch cable injection molding body is realized, when cable is subjected to tension, conical half ring is self-adapting wedge and transmits tension to casing, effectively avoid that injection molding body bears pulling stress and cracks failure, improve the protection reliability and service life of pre-branch cable branch joint.

Description

Technical Field

[0001] This utility model relates to the field of power cable protection technology, specifically to an external protection structure for pre-branched cables. Background Technology

[0002] In power system distribution engineering, pre-branched cables are widely used in important locations such as high-rise buildings, hospitals, and data centers. The branch joints of pre-branched cables are the key parts for realizing the electrical connection between the main cable and the branch cable. They are usually made of injection-molded material as a protective shell and are set at each branch connection location to provide mechanical protection, environmental protection, and electrical insulation for the internal electrical connection.

[0003] Existing pre-branched cable connectors mainly employ a single injection-molded body protection method, relying solely on a factory-prefabricated injection-molded shell for protection. The injection-molded body is typically made of polyvinyl chloride (PVC) or low-smoke halogen-free materials. While possessing good electrical insulation properties, it suffers from the following technical drawbacks: PVC materials are prone to aging under long-term use due to environmental factors such as temperature cycling, ultraviolet radiation, and chemical corrosion. Its operating temperature range is limited to below 80℃. In high or low temperature environments, the material gradually becomes brittle, cracks, and shrinks, leading to sealing failure and reduced mechanical strength.

[0004] Secondly, the injection molded body gradually ages during use, and its mechanical strength continues to decline. When the cable exerts tensile force on the injection molded body under external force, due to the lack of effective external protection, the aged and brittle injection molded material is very prone to cracking at stress concentration points under tensile stress, which in turn leads to overall cracking and failure. Utility Model Content

[0005] In view of the technical problems existing in the background art, this utility model provides a pre-branched cable external protection structure.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows: An external protective structure for pre-branched cables includes an upper shell and a lower shell, with locking units provided at both ends of the upper and lower shells. The locking unit includes a wedge-shaped semi-ring, inside which is a conical semi-ring. A retaining ring is fixedly connected to the inner wall of the wedge-shaped semi-ring. The outer end of the retaining ring is provided with a plurality of first countersunk holes arranged in a circumferential array. The outer end of the conical semi-ring is provided with a second countersunk hole corresponding to the first countersunk hole. A preload spring is provided in the second countersunk hole, and the end of the preload spring near the first countersunk hole abuts against the bottom end of the first countersunk hole. The upper and lower shells are fastened together to form a protective cavity. The locking units at both ends of the upper and lower shells are fastened together to form a locking assembly for locking the cable.

[0007] Optionally, locking components are located at the main cable inlet, main cable outlet, and branch cable outlet of the pre-branched cable. The locking components are used to clamp the cable and transfer the cable tension to the upper and lower housings.

[0008] Optionally, the upper shell has a protrusion on its edge, and the lower shell has a groove on its edge that mates with the protrusion. The upper shell and the lower shell are connected by inserting the protrusion into the groove. Several connecting ears are fixed at the outer ends of both the upper shell and the lower shell.

[0009] Optionally, a sealing groove is provided at the inner end of the retaining ring, and a sealing ring is provided in the sealing groove.

[0010] Optionally, the inner wall of the wedge-shaped semi-ring is provided with an installation ring, which is engaged with an annular plug, and the inner wall of the conical semi-ring is provided with several rectangular rings with fixed intervals.

[0011] Optionally, the inner walls of both the upper and lower shells are provided with an insulating layer, and a filling hole is opened at the top of the upper shell. A sealing head is threaded into the filling hole, and the protective cavity inside the upper and lower shells is filled with fireproof material through the filling hole.

[0012] Optionally, an axial gap is provided between the conical semi-ring and the wedge-shaped semi-ring, the outer conical surface of the conical semi-ring and the inner conical surface of the wedge-shaped semi-ring form a matching taper, and the retaining ring restricts the axial movement range of the conical semi-ring.

[0013] This utility model has the following advantages and beneficial effects: This invention achieves effective protection of the existing injection-molded body and reliable transmission of cable tension by setting an external protective structure and an adaptive locking component. Through the use of a wedge-shaped and conical semi-ring with a tapered structure, combined with the elastic adjustment of the pre-tensioning spring, and utilizing the wedge tightening principle and elastic compensation technology, it provides an adaptive locking function that tightens as the cable is pulled. This method can effectively bear the pull-out stress of the cable and maintain continuous protection of the injection-molded body. Compared with a single injection-molded body protection method, it avoids the cracking failure problem caused by the injection-molded body directly bearing tensile force, and achieves coordinated operation of protection, locking, sealing, and insulation functions, improving the reliability of branch joint protection. Attached Figure Description

[0014] Figure 1 This is an overall structural diagram of the pre-branched cable external protection structure of this utility model; Figure 2 This is a partial view of the external protective structure for pre-branched cables of this utility model. Figure 1 ; Figure 3 This is a partial view of the external protective structure for pre-branched cables of this utility model. Figure 2 ; Figure 4This is a structural diagram of the locking unit of this utility model; Figure 5 This is a partial view of the locking unit of this utility model; Figure 6 This is a cross-sectional view of the external protective structure for the pre-branched cable of this utility model; Figure 7 This utility model Figure 6 A magnified view of a portion of point A in the middle.

[0015] Reference numerals: 1. Upper shell; 2. Lower shell; 3. Wedge-shaped semi-ring; 4. Conical semi-ring; 5. Retaining ring; 6. First countersunk hole; 7. Second countersunk hole; 8. Preload spring; 9. Protrusion; 10. Groove; 11. Connecting ear; 12. Sealing groove; 13. Sealing ring; 14. Mounting ring; 15. Annular plug; 16. Rectangular ring; 17. Insulating layer; 18. Filling hole; 19. Sealing head; 20. Fireproof material. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0017] 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 claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] Example like Figures 1 to 7 As shown, an external protective structure for a pre-branched cable includes an upper shell 1 and a lower shell 2. Locking units are provided at both ends of the upper shell 1 and the lower shell 2. Each locking unit includes a wedge-shaped semi-ring 3, within which a conical semi-ring 4 is provided. A retaining ring 5 is fixedly connected to the inner wall of the wedge-shaped semi-ring 3. The outer end of the retaining ring 5 has several first countersunk holes 6 arranged in a circumferential array. The outer end of the conical semi-ring 4 has a second countersunk hole 7 corresponding to the first countersunk hole 6. A pre-tensioning spring 8 is provided within the second countersunk hole 7, with one end of the pre-tensioning spring 8 near the first countersunk hole 6 abutting against the bottom end of the first countersunk hole 6. The upper shell 1 and the lower shell 2 are fastened together to form a protective cavity. The locking units at both ends of the upper shell 1 and the lower shell 2 are fastened together to form a locking assembly for locking the cable.

[0019] Furthermore, locking components are located at the main cable inlet, main cable outlet, and branch cable outlet of the pre-branched cable. These components clamp the cable and transmit the cable tension to the upper housing 1 and lower housing 2, thus protecting the existing injection-molded body. When the cable is subjected to tensile stress, the conical semi-ring 4 moves forward under the tension, forming a wedge-shaped engagement with the wedge-shaped semi-ring 3 to firmly clamp the cable. Simultaneously, the tension is directly transmitted to the housing structure, preventing the tension from acting directly on the injection-molded body.

[0020] Furthermore, the upper shell 1 has a protruding tab 9 on its edge, and the lower shell 2 has a groove 10 on its edge that mates with the protruding tab 9. The upper shell 1 and the lower shell 2 are connected by inserting the protruding tab 9 into the groove 10. Several connecting ears 11 are fixed to the outer ends of both the upper shell 1 and the lower shell 2. The interlocking connection between the protruding tab 9 and the groove 10 ensures the precise positioning and waterproof sealing of the upper and lower shells, and the connecting ears 11 facilitate the use of bolts or other fasteners to further enhance the reliability of the connection.

[0021] Furthermore, a sealing groove 12 is provided at the inner end of the retaining ring 5, and a sealing ring 13 is provided in the sealing groove 12. The sealing ring 13 is in close contact with the outer sheath of the cable to form an effective sealing protection, preventing moisture, dust and other harmful external substances from entering the protective cavity.

[0022] Furthermore, the inner wall of the wedge-shaped semi-ring 3 is provided with an installation ring 14, which is engaged with an annular plug 15. The inner wall of the conical semi-ring 4 is provided with several rectangular rings 16 spaced at fixed intervals. The installation ring 14 and the annular plug 15 work together to form the first layer of sealing protection. The rectangular rings 16 increase the contact area and friction between the conical semi-ring 4 and the cable, thereby improving the reliability of the clamping effect.

[0023] Furthermore, both the upper shell 1 and the lower shell 2 have an insulating layer 17 on their inner walls. The top of the upper shell 1 has a filling hole 18, which is threaded with a sealing head 19. The protective cavities inside the upper shell 1 and the lower shell 2 are filled with fire-retardant material 20 through the filling hole 18. The insulating layer 17 provides additional electrical insulation protection, the fire-retardant material 20 can effectively block the spread of flames in high temperature or fire conditions, and the sealing head 19 ensures the sealing of the filling hole 18.

[0024] Furthermore, an axial gap is provided between the conical semi-ring 4 and the wedge-shaped semi-ring 3. The outer conical surface of the conical semi-ring 4 and the inner conical surface of the wedge-shaped semi-ring 3 form a mating taper, and the retaining ring 5 restricts the axial movement range of the conical semi-ring 4. The axial gap allows the conical semi-ring 4 to move adaptively under force, the mating taper ensures the wedging effect between the conical semi-ring 4 and the wedge-shaped semi-ring 3, and the restrictive effect of the retaining ring 5 prevents the conical semi-ring 4 from moving excessively.

[0025] like Figures 1 to 7As shown, during use, first place the injection-molded body of the pre-branched cable into the lower half-shell 2, ensuring that the main cable and branch cable pass through the corresponding locking unit respectively; then, the upper half-shell 1 and the lower half-shell 2 are fastened together by the protrusion 9 and the groove 10, and fastened with bolts by the connecting ear 11 to form a complete protective cavity and locking assembly. When the upper half-shell 1 and the lower half-shell 2 are fastened together, the cable contacts the conical half-ring 4 in the locking assembly, causing the pre-tension spring 8 to compress. The elastic force generated by the compression of the pre-tension spring 8 reacts to the conical half-ring 4, making the conical half-ring 4 in close contact with the cable and applying a pre-clamping force to prevent clamping failure.

[0026] After installation, fireproof material 20 is filled into the protective cavity through filling hole 18. Combined with the insulation layer 17 on the inner wall, it provides multiple protections for the entire branch joint, improving the service life and safety reliability of the pre-branched cable branch joint.

[0027] When the cable is in normal condition, the elastic force of the pre-tension spring 8 keeps the conical semi-ring 4 in the neutral position, and the sealing ring 13 contacts the cable outer sheath to form a basic seal; when the cable is subjected to tensile stress, the conical semi-ring 4 moves into the wedge-shaped semi-ring 3 along the axial gap under the action of the tension, and the matching taper formed by the outer conical surface and the inner conical surface produces a wedge tightening effect. The clamping force increases with the increase of the tension, realizing adaptive locking that gets tighter the more it is pulled. Meanwhile, the cable tension is directly transmitted to the upper half-shell 1 and the lower half-shell 2 through the locking assembly, avoiding the tension acting directly on the fragile injection molded body and effectively protecting the injection molded body from pull-out stress damage; when the cable changes size due to thermal expansion and contraction, the elasticity of the pre-tightening spring 8 allows the conical half-ring 4 to self-adjust, which can avoid over-clamping.

[0028] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An external protection structure for pre-branched cables, characterized in that: It includes an upper shell (1) and a lower shell (2), and both ends of the upper shell (1) and the lower shell (2) are provided with locking units; The locking unit includes a wedge-shaped semi-ring (3), a conical semi-ring (4) is provided inside the wedge-shaped semi-ring (3), a retaining ring (5) is fixedly connected to the inner wall of the wedge-shaped semi-ring (3), a plurality of first countersunk holes (6) are provided at the outer end of the retaining ring (5) in a circumferential array, a second countersunk hole (7) corresponding to the first countersunk hole (6) is provided at the outer end of the conical semi-ring (4), a preload spring (8) is provided in the second countersunk hole (7), and the end of the preload spring (8) near the first countersunk hole (6) abuts against the bottom end of the first countersunk hole (6); The upper half shell (1) and the lower half shell (2) are fastened together to form a protective cavity. The locking units at both ends of the upper half shell (1) and the lower half shell (2) are fastened together to form a locking assembly for locking the cable.

2. The external protection structure for a pre-branched cable according to claim 1, characterized in that: The locking assembly is located at the main cable inlet, main cable outlet and branch cable outlet of the pre-branched cable. The locking assembly is used to clamp the cable and transmit the cable tension to the upper half shell (1) and the lower half shell (2).

3. The external protection structure for a pre-branched cable according to claim 1, characterized in that: The upper shell (1) has a protrusion (9) on its edge, and the lower shell (2) has a groove (10) that mates with the protrusion (9) on its edge. The upper shell (1) and the lower shell (2) are connected by inserting the protrusion (9) into the groove (10). The outer ends of the upper shell (1) and the lower shell (2) are each fixed with a number of connecting ears (11).

4. The external protection structure for a pre-branched cable according to claim 1, characterized in that: The inner end of the retaining ring (5) is provided with a sealing groove (12), and a sealing ring (13) is provided in the sealing groove (12).

5. The external protection structure for a pre-branched cable according to claim 1, characterized in that: The inner wall of the wedge-shaped semi-ring (3) is provided with an installation ring (14), and the installation ring (14) is engaged with an annular plug (15). The inner wall of the conical semi-ring (4) is provided with a number of rectangular rings (16) with fixed spacing.

6. The pre-branching cable outer protection structure of claim 1, wherein: The inner walls of the upper shell (1) and the lower shell (2) are provided with an insulating layer (17). The top of the upper shell (1) is provided with a filling hole (18). The filling hole (18) is threaded with a sealing head (19). The protective cavity inside the upper shell (1) and the lower shell (2) is filled with fireproof material (20) through the filling hole (18).

7. The external protection structure for a pre-branched cable according to claim 1, characterized in that: An axial gap is provided between the conical semi-ring (4) and the wedge-shaped semi-ring (3). The outer conical surface of the conical semi-ring (4) and the inner conical surface of the wedge-shaped semi-ring (3) form a matching taper. The retaining ring (5) restricts the axial movement range of the conical semi-ring (4).

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