Indoor cable terminal elastic leading-out device and method

Abstract

The invention discloses an indoor cable terminal elastic leading-out device, which comprises an insulating sleeve, the insulating sleeve comprises a sleeve body, an elastic telescopic structure is arranged in the sleeve body, the elastic telescopic structure comprises spring pressing sheets which are oppositely arranged, and the spring pressing sheets are clamped with a cable terminal connecting pipe and form a conductive path with the cable terminal connecting pipe; one end, far away from the cable terminal connecting pipe, of the elastic telescopic structure is detachably connected with a terminal leading-out structure, so that cable test space can be expanded, creepage distance can be increased, terminal electric field distribution can be improved, the requirement of voltage withstanding test insulation distance can be met, and the problem that in the high-voltage cable test process, the safety distance is insufficient due to limited test space is solved. And breakdown discharge of the cable to the ground or between phases is caused, and instrument and equipment and personal safety are threatened. And an assembled structure is adopted, so that flexible disassembly and assembly are facilitated, cable terminals of different models can be matched, the effective insulation distance of the cable terminal is prolonged, the creepage distance is increased, and the terminal electric field distribution is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power cables, and particularly relates to an elastic lead-out device and method for indoor cable terminals. Background Art

[0002] The statements here only provide the background art related to the present invention and do not necessarily constitute the prior art.

[0003] Due to the advantages of high safety, strong power supply reliability, long service life, etc. of cables, in recent years, the proportion of cable lines in power lines has been increasing continuously. To ensure the power supply reliability of cable lines, the work of evaluating the insulation status of cables by operation and maintenance personnel has been increasing day by day. Among them, tests such as high-voltage cable insulation, withstand voltage, partial discharge, and dielectric loss are effective means to evaluate the insulation status of cable lines.

[0004] During the high-voltage cable test process, in order to avoid breakdown of the T-shaped plug or affecting the test results during the test, it is required to pull out the indoor cable terminal T-shaped plug. According to relevant regulations such as the "Test Regulations for Distribution Cable Lines (GDW11838-2018)", during the test process, a voltage of more than 16 kV needs to be applied to the cable. However, due to the narrow space between the cable compartments of high-voltage switchgear and ring main units, the phase-to-phase / phase-to-ground distance of the metal pipes at the three-phase terminals of the cable is mostly insufficient for the safety distance in most cases, and breakdown discharge is likely to occur during the withstand voltage test, which poses a great safety risk to the test equipment and personnel. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, and provide an elastic lead-out device and method for indoor cable terminals, which can match different cable terminal models, lead out the indoor cable terminals, extend the effective insulation distance of the cable terminals, can effectively increase the creepage distance, improve the electric field distribution at the terminals, ensure the safety of personnel and equipment, and solve the problem that during the high-voltage cable test process, due to the limited test space and insufficient safety distance, breakdown discharge between the cable and the ground or between phases occurs, thus threatening the safety of instrument equipment and personnel.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] On the one hand, the technical solution of the present invention provides an elastic lead-out device for indoor cable terminals, including: an insulating sleeve, the insulating sleeve includes a cylinder body, an elastic telescopic structure is arranged inside the cylinder body, the elastic telescopic structure includes spring pressing pieces arranged oppositely, the spring pressing pieces are clamped with the cable terminal pipe and form a conductive path with the cable terminal pipe; one end of the elastic telescopic structure far from the cable terminal pipe is detachably connected with a terminal lead-out structure.

[0008] In at least one embodiment, an external thread interface is provided at one end of the cylinder body away from the elastic telescopic structure, and an internal thread screw cap is sleeved thereon.

[0009] In at least one embodiment, the spring pressing piece is an S-shaped spring pressing piece, and a support screw installation hole is opened at the rear end thereof; a through hole is opened at a position on the insulating sleeve corresponding to the support screw installation hole, and the support screw passes through the insulating sleeve and the S-shaped spring pressing piece and is fixed at both ends by external thread screws;

[0010] Alternatively, the elastic telescopic structure includes a housing, and the spring pressing piece is arranged inside the housing; the spring pressing piece is an S-shaped spring pressing piece, and a support screw installation hole is opened at the rear end thereof; through holes are opened at positions on the housing and the insulating sleeve corresponding to the support screw installation hole, and the support screw passes through the insulating sleeve, the housing and the S-shaped spring pressing piece and is fixed at both ends by external thread screws.

[0011] In at least one embodiment, along the support screw, pressing piece springs are arranged between the external thread screw and the spring pressing piece, and between two spring pressing pieces.

[0012] In at least one embodiment, a guiding force ball is arranged between the external thread screw and the pressing piece spring;

[0013] Alternatively, the external thread screw is provided with a linkage rod, and a guiding force ball is arranged between the linkage rod and the pressing piece spring.

[0014] In at least one embodiment, the terminal lead-out structure includes an elastic buckle and a flexible lead; the elastic buckle is fixedly connected to the spring pressing piece and is detachably connected to the flexible lead.

[0015] In at least one embodiment, the elastic buckle includes a buckle spring with one end fixedly connected to the spring pressing piece, and the other end of the buckle spring is fixedly connected to an elastic ball; a wedge-shaped contactor pressing piece is arranged between two elastic balls; a wedge-shaped contactor connection hole is fixedly installed at the open end of the wedge-shaped contactor pressing piece.

[0016] In at least one embodiment, one end of the flexible lead is provided with a mounting bolt, and the other end is provided with a terminal mounting hole.

[0017] In at least one embodiment, the outer side of the flexible lead is coated with an insulating sheath; a plurality of insulating umbrella skirts are arranged on the surface of the insulating sheath.

[0018] On the other hand, the technical solution of the present invention also provides an indoor cable terminal elastic lead-out method, including:

[0019] Step 1: Sequentially pass the support screw through the insulating cylinder body, the upper spring pressing piece, the lower spring pressing piece, the insulating cylinder body, install the pressing piece spring along the support screw, and install external thread screws at both ends of the support screw;

[0020] Step 2: Insert the metal nozzle of the cable terminal into the insulating sleeve of the indoor cable terminal elastic lead-out device. The concave point of the spring pressing piece snaps into the hole of the metal nozzle, enabling an effective overlap between the stress cone of the cable terminal and the insulating sleeve.

[0021] Step 3: Screw the external thread screw into the insulating cylinder body. The linkage rod of the external thread screw drives the guiding ball to move downward, compressing the spring inside the elastic snap. The distance between the two spring pressing pieces decreases, causing the concave point of the spring pressing piece to tightly engage with the hole of the cable metal nozzle.

[0022] Step 4: Push the internal thread cover to the external thread interface of the insulating sleeve. By tightening the internal thread cover, ensure that the insulating sleeve tightly sleeves the stress cone of the cable terminal.

[0023] Step 5: Connect the flexible lead to the connection hole of the wedge-shaped contactor through the mounting bolt. Crimp a terminal at the end of the flexible lead and connect it to the high-voltage output terminal of the test equipment.

[0024] The beneficial effects of the above technical solution of the present invention are as follows:

[0025] 1) An indoor cable terminal elastic lead-out device of the present invention is tightly connected to the cable three-phase terminal wiring terminals in the insulating sleeve in an elastic snap manner. The three-phase terminals of the cable are led out of the cable chamber through the flexible lead, and an insulating umbrella skirt is installed at the end of the flexible lead, which can expand the cable test space, increase the creepage distance, and improve the electric field distribution at the terminal to meet the requirements of the insulation distance for the withstand voltage test, solving the problem that during the high-voltage cable test, due to the limited test space and insufficient safety distance, the cable breaks down and discharges to the ground or between phases, thus threatening the safety of the instrument equipment and personnel.

[0026] 2) An indoor cable terminal elastic lead-out device of the present invention adopts an assembled structure, which is convenient for flexible disassembly and installation, can match different models of cable terminals, extends the effective insulation distance of the cable terminal, increases the creepage distance, and improves the electric field distribution at the terminal.

[0027] 3) An indoor cable terminal elastic lead-out device of the present invention can be applied to the elastic extension scenario of the lead of the 10 kV distribution network indoor cable terminal and the scenario where the high-voltage cable test space is narrow and the electric field distribution at the terminal connection needs to be improved. It belongs to a high-voltage cable test supporting terminal conversion device, and relevant safety regulations and system requirements must be strictly observed during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0029] Figure 1It is a schematic diagram of the overall structure of an indoor cable terminal elastic lead-out device of the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of an insulating sleeve of an indoor cable terminal elastic lead-out device of the present invention;

[0031] Figure 3 It is a schematic diagram of a terminal lead-out structure of an indoor cable terminal elastic lead-out device of the present invention;

[0032] Figure 4 The present invention is a schematic diagram of an elastic telescopic structure of an indoor cable terminal elastic lead-out device.

[0033] In the figure: 1. Cylinder; 2. External thread interface; 3. Internal thread screw cover; 4. Support screw; 5. Pressure plate spring; 6. Guide ball; 7. External thread screw; 8. S-type spring pressure plate; 9. Elastic ball; 10. Spring-type buckle; 11. Wedge contactor connection hole; 12. Mounting bolt; 13. Flexible lead; 14. Terminal mounting hole; 15. Insulating umbrella skirt.

[0034] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] As introduced in the background technology, the purpose of the present invention is to overcome the deficiencies existing in the above-mentioned prior art and to provide an indoor cable terminal elastic lead-out device and method, which can match different cable terminal models, lead out indoor cable terminals, extend the effective insulation distance of the cable terminals, increase the creepage distance, improve the terminal electric field distribution, ensure the safety of personnel and equipment, and solve the problem that during the high-voltage cable test, the test space is limited and the safety distance is insufficient, resulting in cable breakdown discharge to the ground or between phases, thereby threatening the safety of instruments and equipment and personnel.

[0037] Example 1

[0038] like Figures 1-4 As shown, this embodiment discloses an indoor cable terminal elastic lead-out device, including: an insulating sleeve, the insulating sleeve includes a cylinder body 1, an elastic telescopic structure is arranged inside the cylinder body 1, the elastic telescopic structure includes relatively arranged spring pressing pieces, the spring pressing pieces are clamped with the cable terminal pipe and form a conductive path with the cable terminal pipe; the end of the elastic telescopic structure away from the cable terminal pipe is detachably connected with the terminal lead-out structure.

[0039] In this embodiment, one end of the cylinder body 1 of the insulating sleeve, which is away from the elastic telescopic structure, is in the shape of a tapered threaded tube, and its surface is provided with external threads to form an external thread interface 2. An internal thread screw cap 3 is sleeved thereon. The threads inside the internal thread screw cap 3 match the threads of the external thread interface 2. Pushing the internal thread screw cap 3 to the external thread interface 2 and screwing the internal thread screw cap 3 tightly towards the outside of the cylinder body 1 can reduce the size of the port of the cylinder body 1, clamp the insulating sleeve and the stress cone of the cable terminal, and can be applicable to the sealing and fixing of cable terminal nozzles of different models and specifications, effectively preventing the cable terminal from loosening and falling off, and forming an effective insulation isolation between the cable terminal metal nozzle and the external environment.

[0040] In this embodiment, the spring piece of the elastic telescopic structure is an S-shaped spring piece 8, that is, a spring piece with an S-shaped front end and a straight-shaped rear end. A support screw mounting hole is opened at the rear end of the spring piece for the support screw 4 to pass through. A through hole is also opened at the position of the insulating sleeve corresponding to the support screw mounting hole. The support screw 4 passes through the cylinder body 1, the spring piece, the spring piece, and the cylinder body 1 in sequence, and is fixed at both ends of the support screw 4 by an external thread screw 7.

[0041] In another embodiment, in order to make the internal space of the insulating cylinder body more clearly partitioned, a housing is designed for the elastic telescopic structure, and the spring piece is arranged inside the housing. A through hole is also opened at the position of the housing corresponding to the support screw mounting hole. During installation, the support screw 4 passes through the cylinder body 1, the housing, the spring piece, the spring piece, the housing, and the cylinder body 1 in sequence, and is fixed at both ends of the support screw 4 by an external thread screw 7.

[0042] In this embodiment, along the support screw 4, pressure plate springs 5 are arranged between the external thread screw 7 and the spring piece, and between the two spring pieces. A guide ball 6 is arranged between the external thread screw 7 and the pressure plate spring 5. The pressure plate spring 5, the guide ball 6, the support screw 4, and the external thread screw 7 together form an elastic telescopic device. When the thickness of the cable terminal metal nozzle is different and the height of the spring piece needs to be adjusted, the external thread screw 7 can be screwed tight or unscrewed. The guide ball 6 drives the pressure plate spring 5 to expand and contract up and down, and the height of the spring piece can be freely adjusted to ensure that the spring piece is tightly pressed against the cable terminal metal nozzle.

[0043] To ensure better insulation performance, the support screw 4, the external thread screw 7, and the pressure plate spring 5 are all made of non-metallic materials.

[0044] In another embodiment, the external thread screw 7 can be an external thread screw 7 provided with a linkage rod, and the guide ball 6 is arranged between the linkage rod and the pressure plate spring 5.

[0045] In this embodiment, the terminal lead structure includes an elastic buckle and a flexible lead 13. A buckle mounting hole with a thread inside is opened at the end of the spring pressing piece, and the elastic buckle 10 is fixedly connected to the end of the spring pressing piece by screws and detachably connected to the flexible lead by screws.

[0046] Specifically, the elastic buckle 10 includes a buckle spring, one end of which is fixedly connected to the end of the spring pressure piece by a screw, and the other end is fixedly connected to an elastic ball 9, a wedge-shaped contactor pressure piece is arranged between the upper and lower elastic balls 9, and a wedge-shaped contactor connecting hole 11 is fixedly installed at one end of the opening of the wedge-shaped contactor pressure piece, and a mounting thread is arranged in the wedge-shaped contactor connecting hole 11. The elastic ball 9 of the elastic buckle 10 is in close contact with the wedge-shaped contactor pressure piece by the downward pressure of the buckle spring. Since the wedge-shaped contactor pressure piece is elastic, when matching different cable terminal pipe thicknesses, it can ensure that the spring pressure piece always presses the cable terminal pipe tightly. When the spring pressure piece moves up or down, the elastic ball 9 moves up and down in linkage. During the expansion and contraction process of the buckle spring connected to the elastic ball 9, the elastic ball 9 always maintains close contact with the wedge-shaped contactor, which can ensure that the conductive path is in good contact when the cable terminals of different models and specifications are led out.

[0047] One end of the flexible lead 13 is provided with a mounting bolt 12, which is matched with the mounting thread in the wedge contactor connection hole 11, and can realize the detachable connection of the flexible lead 13. At the same time, the bolt connection can also prevent the problem of poor contact caused by the swing of the flexible lead 13. A terminal mounting hole 14 is provided at the other end of the flexible lead 13 to realize crimping with the terminal, so as to serve as a connection interface of the high-voltage test equipment.

[0048] In addition, the outer side of the flexible lead 13 is also covered with a rubber insulating sheath, and a plurality of insulating sheds 15 are arranged on the surface of the rubber insulating sheath. The position of the insulating sheds 15 can be flexibly adjusted without being limited by the installation space, which can effectively increase the creepage distance and improve the electric field distribution at the cable terminal.

[0049] When conducting high-voltage cable tests and the insulation distance of the metal nozzle of the cable terminal is insufficient, it is necessary to insert the metal nozzle of the cable terminal deep into the cylinder body 1 of the insulating sleeve. The spring pressing piece is recessed and clamped on the nozzle hole of the metal nozzle. The stress cone of the cable terminal effectively overlaps with the insulating cylinder body 1. At this time, the internal thread screw cap 3 is matched with the external thread interface 2 and tightened outward, so that the metal nozzle of the cable terminal is insulated from the external environment and no discharge channel can be formed. At the same time, it plays a stabilizing role for the cable terminal. Screwing the external thread screws 7 at both ends of the support screw 4 in and out, the guiding ball 6 and the support screw 4 limit the spring pressing piece. The guiding ball 6 is driven by the linkage rod of the external thread screw 7 to move up and down, so that the pressing spring 5 is released or tightened, and the height of the spring pressing piece can be freely adjusted. Fix the elastic buckle 10 on the two spring pressing pieces with screws. The spring pressing piece and the elastic ball 9 form an up-and-down linkage. When the spring pressing piece moves up or down, the buckle spring inside the elastic buckle 10 is relaxed and tightened. During the telescopic process of the spring pressing piece, the buckle spring inside the elastic buckle remains in a tightened state, and the elastic ball 9 is always in contact with the S-shaped spring pressing piece 8, ensuring that the metal nozzle of the cable terminal - S-shaped spring pressing piece 8 - elastic ball 9 - wedge-shaped contactor pressing piece forms an electrical connection loop. After the installation bolt 12 of the flexible lead 13 is inserted into the wedge-shaped contactor connection hole 11 and tightened, the terminal is crimped at the terminal installation hole 14 as the connection interface of the high-voltage test equipment, which can extend the effective insulation length of the cable terminal. The flexible installation and adjustment of the insulating umbrella skirt 15 can further increase the creepage distance and improve the electric field distribution of the cable terminal.

[0050] Embodiment 2

[0051] This embodiment discloses an elastic lead-out method for indoor cable terminals, including:

[0052] Step 1: Pass the support screw 4 through the insulating cylinder body 1, the upper spring pressing piece, the lower spring pressing piece, and the insulating cylinder body 1 in sequence, and install the pressing spring 5 between the external thread screw 7 and the spring pressing piece and between the two spring pressing pieces along the support screw 4, and install the external thread screws 7 at both ends of the support screw 4;

[0053] Step 2: Insert the metal nozzle of the cable terminal into the insulating sleeve of the elastic lead-out device for indoor cable terminals. The spring pressing piece is recessed and clamped into the nozzle hole of the metal nozzle, so that the stress cone of the cable terminal forms an effective overlap with the insulating sleeve;

[0054] Step 3: Screw the external thread screw 7 into the insulating cylinder body. The linkage rod of the external thread screw 7 drives the guiding ball 6 to move downward, the spring inside the elastic buckle is tightened, and the distance between the two spring pressing pieces is reduced, so that the recessed point of the spring pressing piece is tightly clamped with the nozzle hole of the cable metal nozzle;

[0055] Step 4: Push the internal thread screw cap 3 to the external thread interface 2 of the insulating sleeve, and ensure that the insulating sleeve tightly sleeves the stress cone of the cable terminal by tightening the internal thread screw cap 3;

[0056] Step 5: Connect the flexible lead 13 to the wedge contact connection hole 11 through the mounting bolt 12, crimp a terminal at the end of the flexible lead 13, and connect it to the high-voltage output terminal of the test equipment.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An elastic lead-out device for indoor cable terminals, characterized in that, Comprising: An insulating sleeve, the insulating sleeve includes a cylinder body, an elastic telescopic structure is arranged inside the cylinder body, the elastic telescopic structure includes spring pressing pieces arranged oppositely, the spring pressing pieces are clamped with a cable terminal adapter and form a conductive path with the cable terminal adapter; one end of the elastic telescopic structure far away from the cable terminal adapter is detachably connected with a terminal lead-out structure.

2. The elastic lead-out device for indoor cable terminals according to claim 1, characterized in that, One end of the cylinder body far away from the elastic telescopic structure is provided with an external thread interface, and an internal thread screw cap is sleeved thereon.

3. The elastic lead-out device for indoor cable terminals according to claim 1, characterized in that, The spring pressing piece is an S-shaped spring pressing piece, and a support screw installation hole is opened at the rear end thereof; a through hole is opened at a position on the insulating sleeve corresponding to the support screw installation hole, and the support screw passes through the insulating sleeve and the S-shaped spring pressing piece and is fixed at both ends by an external thread screw; Alternatively, the elastic telescopic structure includes a housing, and the spring pressing piece is arranged inside the housing; the spring pressing piece is an S-shaped spring pressing piece, and a support screw installation hole is opened at the rear end thereof; through holes are opened at positions on the housing and the insulating sleeve corresponding to the support screw installation hole, and the support screw passes through the insulating sleeve, the housing and the S-shaped spring pressing piece and is fixed at both ends by an external thread screw.

4. The elastic lead-out device for indoor cable terminals according to claim 3, characterized in that, Along the support screw, a pressing piece spring is arranged between the external thread screw and the spring pressing piece, and between two spring pressing pieces.

5. The elastic lead-out device for indoor cable terminals according to claim 4, characterized in that, A guiding ball is arranged between the external thread screw and the pressing piece spring; Alternatively, the external thread screw is provided with a linkage rod, and a guiding ball is arranged between the linkage rod and the pressing piece spring.

6. The elastic lead-out device for indoor cable terminals according to claim 1, wherein, The terminal lead-out structure includes an elastic buckle and a flexible lead; the elastic buckle is fixedly connected with the spring pressing piece and is detachably connected with the flexible lead.

7. The elastic lead-out device for indoor cable terminals according to claim 6, characterized in that, The elastic buckle includes a buckle spring fixedly connected to one end of the spring pressing piece, and the other end of the buckle spring is fixedly connected with an elastic ball; a wedge-shaped contactor pressing piece is arranged between two elastic balls; a wedge-shaped contactor connection hole is fixedly installed at the open end of the wedge-shaped contactor pressing piece.

8. The elastic lead-out device for indoor cable terminals according to claim 6, wherein, One end of the flexible lead is provided with a mounting bolt, and the other end is provided with a terminal mounting hole.

9. The elastic lead-out device for indoor cable terminals according to claim 1, characterized in that, The outer side of the flexible lead is coated with an insulating sheath; a plurality of insulating umbrella skirts are arranged on the surface of the insulating sheath.

10. A method for elastically leading out an indoor cable terminal, characterized in that, Comprising: Step 1: Pass the support screw through the insulating cylinder body, the upper spring pressing piece, the lower spring pressing piece, and the insulating cylinder body in sequence, install the pressing piece spring along the support screw, and install external thread screws at both ends of the support screw; Step 2: Insert the cable terminal metal adapter into the insulating sleeve of the indoor cable terminal elastic lead-out device, and the concave point of the spring pressing piece is clamped into the hole of the metal adapter, so that the cable terminal stress cone and the insulating sleeve form an effective overlap; Step 3: Screw the external thread screw into the insulating cylinder body, the linkage rod of the external thread screw drives the guiding ball to move downward, the spring inside the elastic buckle is tightened, the distance between the two spring pressing pieces is reduced, so that the concave point of the spring pressing piece is tightly clamped with the hole of the cable metal adapter; Step 4: Push the internal thread screw cap to the external thread interface of the insulating sleeve, and by tightening the internal thread screw cap, ensure that the insulating sleeve tightly sleeves the cable terminal stress cone; Step 5: Connect the flexible lead to the wedge-shaped contactor connection hole through the mounting bolt, and crimp a terminal at the end of the flexible lead to connect with the high-voltage output end of the test equipment.

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