Underground pipe gallery high-power multi-core pre-branched cable double-branch structure

Abstract

A double-branch structure of a high-power multi-core pre-branched cable for an underground pipe gallery is characterized by comprising a main cable, two branch cables, a water-blocking tape, a C-shaped crimping buckle and an injection molding shell, the structure design is simple, on the basis of a common power cable, cable series product varieties are enriched, the waterproof performance of a pre-branch body is further improved by designing a multi-layer water-blocking tape water-blocking technology at a connecting port, and the cable has the advantages of being good in environment-friendly, moisture-proof and water-blocking performance, improving line safety and reliability, reducing construction of a main line power distribution cabinet, and reducing construction cost. Line loss and installation cost are greatly reduced, the method can be widely applied to newly-built or quality-improved and rebuilt urban underground pipe gallery projects, the urban power supply requirement is met, the economic value and application value are quite considerable, and the safety and reliability of overall operation of an urban smart power grid are improved.

Description

Technical Field

[0001] This utility model relates to the field of pre-branched cable technology, and in particular to a double-branch structure for a high-power multi-core pre-branched cable for underground utility tunnels. Background Technology

[0002] Currently, the power cables in underground utility tunnel projects, as the main network of the city, are generally large-capacity or distribute high-power loads, providing power for the production, life and travel of urban residents. In the branch lines, the cables need to be switched up and down multiple times according to the power distribution tasks. Therefore, more distribution switch cabinets and conversion boxes need to be built near the lines, which greatly increases the construction cost and line loss of the lines.

[0003] To reduce the construction cost of distribution cabinets and conversion boxes, a common method of branching is to directly connect the main cable to the branch cable on the main line using piercing clamps. However, due to the poor sealing and waterproofing performance of piercing clamps, and the fact that underground pipe corridors are often damp due to seasonal characteristics, the joints are prone to water ingress or moisture, which can lead to short circuits in the cables and threaten the safe operation of the line. When the line vibrates, the piercing clamps are in rigid contact with the main cable and are prone to loosening during vibration, resulting in unstable voltage. Summary of the Invention

[0004] This utility model addresses the problems mentioned in the background art by providing a dual-branch structure for high-power multi-core pre-branched cables in underground utility tunnels. When used in underground utility tunnel cable lines, it can reduce the construction cost of outdoor distribution cabinets or junction boxes, reduce line losses, provide good moisture resistance, stabilize line voltage, and improve the overall safety and reliability of underground utility tunnel power grid branch lines.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A dual-branch structure for a high-power multi-core pre-branched cable in an underground utility tunnel, characterized by comprising a main cable, two branch cables, a water-blocking strip, a C-shaped crimp fastener, and an injection-molded housing;

[0007] The main cable has a cross-sectional area of ​​240 mm². 2 -400mm 2 Insulated copper wire, including the front end and the back end;

[0008] The two branch cables have a cross-sectional area of ​​50 mm². 2 -95mm 2 Insulated copper wire, including connecting end and outgoing end;

[0009] The outlet ends of the two branch cables are positioned opposite each other on both sides of the rear end of the main cable. The bare copper conductor ends of the corresponding phases of the branch cables are mechanically crimped with the bare copper conductors with stripped insulation layers of the corresponding phases between the front and rear ends of the main cable by the C-shaped crimping buckle.

[0010] The water-blocking strips are respectively provided on the outer walls of the front and rear ends of the main cable and on the outer walls of the outlet ends of the branch cables;

[0011] The main cable and the branch cables connected to it form a cable pre-branching body;

[0012] The injection-molded shell is made of insulating polymer material and is injection-molded onto the pre-branched cable body. The front and rear ends of the main cable with the water-blocking strip and the outlet ends of the branch cables are completely covered in the injection-molded shell.

[0013] A further aspect of this invention is that, in order to ensure insulation and moisture-proof performance, the thickness of the injection-molded shell on any surface of the pre-branched cable body is greater than or equal to 4.5 mm.

[0014] A further aspect of this invention is that, in order to ensure the moisture-proof effect, the thickness of a single layer of the water-blocking tape is 0.25mm, and it is overlapped and wrapped in 6-8 layers.

[0015] The beneficial effects of this utility model are: the structural design is simple, and the multi-layer water-blocking strip design at the connection port further enhances the waterproof performance of the pre-branched body, making the cable have excellent environmental protection, moisture-proof and water-blocking performance. The double-branch opposing structure at the outlet end can avoid uneven distribution of the injection molding shell thickness during injection molding, increase the safety and reliability of the cable line, reduce the construction of main line distribution cabinets, greatly reduce line loss and installation costs, and can be widely used in new construction or upgrading of urban underground pipe gallery projects to meet urban power supply needs. The economic and application value is considerable, and it improves the overall safety and reliability of the urban smart grid operation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Example

[0018] A dual-branch structure for a high-power multi-core pre-branched cable in an underground utility tunnel includes a main cable 1, two branch cables 2, a water-blocking strip 3, a C-shaped crimp fastener 4, and an injection-molded shell 5.

[0019] The main cable 1 has a cross-sectional area of ​​240 mm². 2-400mm 2 The insulated copper wire includes a front end 11 and a rear end 12;

[0020] The two branch cables 2 have a cross-sectional area of ​​50 mm². 2 -95mm 2 The insulated copper wire includes a connecting end 21 and an output end 22;

[0021] The outlet ends 22 of the two branch cables 2 are arranged opposite to each other on both sides of the rear end 12 of the main cable 1. The bare copper wire end of the corresponding phase of the connection end 21 of the branch cable 2 and the bare copper wire with stripped insulation layer of the corresponding phase between the front end 11 and the rear end 12 of the main cable 1 are mechanically crimped by the C-shaped crimping buckle 4.

[0022] The water-blocking strip 3 is provided on the outer wall of the front end 11 and rear end 12 of the main cable 1 and on the outer wall of the outlet end 22 of the branch cable 2, respectively.

[0023] The main cable 1 and the branch cables 2 connected to it form a cable pre-branching body;

[0024] The injection-molded housing 5 is made of insulating polymer material and is injection-molded onto the pre-branched cable body. The front end 11 and rear end 12 of the main cable 1 with the water-blocking strip 3 and the outlet end 22 of the branch cable 2 are completely covered in the injection-molded housing 5.

[0025] To ensure insulation and moisture protection, the thickness of the injection-molded shell 5 on any surface of the pre-branched cable body is greater than or equal to 4.5 mm.

[0026] To ensure the moisture-proof effect, the water-blocking tape 3 has a single layer thickness of 0.25mm and is wrapped in 6-8 layers.

Claims

1. A dual-branch structure for high-power multi-core pre-branched cables in underground utility tunnels, characterized in that... Includes the main cable, two branch cables, water-blocking tape, C-shaped crimp fasteners, and injection-molded housing; The main cable has a cross-sectional area of ​​240 mm². 2 -400mm 2 Insulated copper wire, including the front end and the back end; The two branch cables have a cross-sectional area of ​​50 mm². 2 -95mm 2 Insulated copper wire, including connecting end and outgoing end; The outlet ends of the two branch cables are positioned opposite each other on both sides of the rear end of the main cable. The bare copper conductor ends of the corresponding phases of the branch cables are mechanically crimped with the bare copper conductors with stripped insulation layers of the corresponding phases between the front and rear ends of the main cable by the C-shaped crimping buckle. The water-blocking strips are respectively provided on the outer walls of the front and rear ends of the main cable and on the outer walls of the outlet ends of the branch cables; The main cable and the branch cables connected to it form a cable pre-branching body; The injection-molded shell is made of insulating polymer material and is injection-molded onto the pre-branched cable body. The front and rear ends of the main cable with the water-blocking strip and the outlet ends of the branch cables are completely covered in the injection-molded shell.

2. The dual-branch structure for high-power multi-core pre-branched cables in underground utility tunnels as described in claim 1, characterized in that... The thickness of the injection-molded shell on any surface of the pre-branched cable body is greater than or equal to 4.5 mm.

3. A dual-branch structure for high-power multi-core pre-branched cables in underground utility tunnels as described in claim 1 or 2, characterized in that... The water-blocking tape has a single-layer thickness of 0.25mm and is wrapped in 6-8 overlapping layers.

Images