Cable grounding box

Abstract

The invention belongs to the technical field of power transmission cables, and particularly discloses a cable grounding box which comprises a box body, an upper connecting terminal board, a lower connecting terminal board and a voltage limiter are connected in the box body, the upper connecting terminal board is located on the upper portion of the box body, the lower connecting terminal board is located on the lower portion of the box body, and the voltage limiter is located on the lower portion of the box body. The voltage limiter is connected and conducted with the upper connecting terminal board and the lower connecting terminal board; the top end of the box body is connected with three upper wall bushings, the bottom end of the box body is connected with a lower wall bushing, and the upper wall bushings and the lower wall bushing are respectively connected with the upper connection terminal board and the lower connection terminal board; the top of the box body is further connected with a limiting unit, the limiting unit is provided with a limiting groove for a cable to penetrate through, and the end of the cable is connected with a binding post of the upper wall bushing. According to the invention, the problems of poor adaptability and unreliable connection in the grounding process of 35kv and below cables can be solved.

Description

Technical Field

[0001] This invention relates to the field of power transmission cable technology, and more specifically to a cable grounding box. Background Technology

[0002] In power transmission and distribution networks, single-core power cables are widely used in power transmission scenarios of different voltage levels due to their advantages such as large transmission capacity and flexible laying. Among them, single-core power cables with voltage levels of 35kV and below play an important role in urban power distribution networks and industrial plant power supply because they are suitable for short-to-medium distance and small-to-medium capacity power transmission needs.

[0003] Reliable grounding of the cable's outer sheath and shielding layer is a crucial aspect of ensuring the safe and stable operation of power cables. It not only effectively suppresses induced voltages generated during cable operation, preventing insulation breakdown of the outer sheath, but also provides a smooth discharge path for fault currents in the event of a cable fault, reducing the risk of fault escalation. Therefore, cable grounding boxes, as the core equipment for achieving this function, are widely used in the installation and maintenance of power cable lines.

[0004] However, existing cable grounding boxes are mainly designed for the operational requirements of 66kV and above high-voltage single-core power cables. These grounding boxes use a 10kV cable entry wiring method, adapting to the structural characteristics of 66kV and above cable terminals. For this voltage level, a grounding cable can be easily installed from the side of the cable head, thus achieving a reliable connection with the grounding box.

[0005] However, for single-core power cables of 35kV and below, their terminal structure differs significantly from that of high-voltage cables. During construction, the terminal of a single-core power cable of 35kV and below can only extend a braided strip (such as aluminum or copper braided strip) from the armor and shielding layers, which cannot be adapted to the cable entry wiring method of existing grounding boxes. This structural difference leads to two core problems with existing grounding boxes in grounding scenarios for cables of 35kV and below: First, the design specifications and structural dimensions of existing grounding boxes are not sufficiently compatible with cables of 35kV and below, and direct use will result in unnecessary waste of equipment resources; second, to solve the connection problem on construction sites, a temporary treatment method is usually adopted, which involves bundling the braided strip with the 10kV grounding cable on site and then insulating it. This method not only makes it difficult to guarantee the reliability and stability of the connection, but also easily leads to loosening or poor contact due to vibration, electrochemical corrosion, and other factors. It also increases the complexity of construction operations, reduces construction efficiency, and affects the standardization and aesthetics of on-site installation.

[0006] In addition, existing grounding boxes for high-voltage cables often have problems such as numerous installation accessories and large box thickness. In installation scenarios with limited space, such as the bottom of switchgear, they are difficult to meet the grounding installation requirements of 35kV and below cable lines, which further limits their application in medium and low voltage distribution networks.

[0007] In summary, the existing technology lacks a cable grounding box specifically adapted to the grounding requirements of the outer sheath and shielding layer of single-core power cables of 35kV and below. This fails to solve the problems of poor compatibility, unreliable connection, inconvenient construction, and insufficient spatial adaptability in the grounding process of cables of this voltage level. Therefore, the development of a dedicated grounding box with strong targeting and reliable performance has important practical significance and application value. Summary of the Invention

[0008] This invention provides a cable grounding box, which aims to solve the problems of poor compatibility and unreliable connection in the grounding process of 35kV and below cables.

[0009] The present invention is achieved through the following technical solution: a cable grounding box, including a box body, wherein an upper connecting terminal plate, a lower connecting terminal plate and a voltage limiter are connected inside the box body, the upper connecting terminal plate is located at the upper part of the box body, the lower connecting terminal plate is located at the lower part of the box body, and the voltage limiter is connected and conductive to the upper connecting terminal plate and the lower connecting terminal plate; The top of the box is connected to three upper through-wall sleeves, and the bottom of the box is connected to one lower through-wall sleeve. The upper through-wall sleeve and the lower through-wall sleeve are respectively connected to the upper connecting terminal plate and the lower connecting terminal plate. The top of the enclosure is also connected to a limiting unit, which has a limiting groove for the cable to pass through. The end of the cable is connected to the terminal of the upper through-wall sleeve.

[0010] Compared with existing technologies, this solution has the following advantages and beneficial effects: In this embodiment, the limiting unit and limiting groove set on the top of the box can pre-fix and guide the cable (braided lead end), avoiding the cable from sagging due to its own weight and being pulled by external force, which would cause the connection part with the upper wall bushing terminal to be stressed. This ensures good compatibility and more reliable connection during the grounding process of 35kV and below cables. At the same time, it can help construction personnel quickly align the connection position of the cable and the terminal without repeated adjustments. It is especially suitable for installation operations in narrow spaces such as the bottom of switch cabinets and cable trenches, improving construction efficiency.

[0011] The limiting unit not only guides the cable but also shares the tensile force at the cable connection point, transferring the external load to the top of the box. This prevents the terminal block of the wall bushing from deforming or breaking due to long-term stress, thus extending the service life of the grounding box. The fixed layout design of the upper and lower connecting terminal plates also ensures the mechanical stability of the internal circuit connection, making it suitable for dynamic operating scenarios such as equipment vibration and cable thermal expansion and contraction in industrial plants.

[0012] The combination design of three wall bushings and upper connection terminal blocks facilitates the adaptation to the structural characteristics of single-core cables (three-phase) of 35kV and below. The braided tape leading out from the cable armor / shielding layer can be directly connected to the terminal block of the wall bushing without the need for temporary on-site modification or bundling. This solves the problem of insufficient adaptability of traditional high-voltage grounding boxes (66kV and above) to medium and low voltage small cross-section cables, and avoids waste of equipment resources.

[0013] The three wall bushings at the top of the enclosure correspond to the independent wiring of the three-phase cables, while the one wall bushing at the bottom centrally leads the grounding current, forming a reasonable circuit of three-phase branching and single-point grounding. This not only meets the electrical requirements of independent three-phase grounding for single-core cables, but also simplifies the connection process between the grounding down conductor and the main grounding grid, making it suitable for wiring logic in medium and low voltage scenarios such as urban power distribution networks and switchgear.

[0014] The upper and lower connecting terminal blocks serve as intermediate transition carriers between the upper wall bushing and the voltage limiter, and between the voltage limiter and the lower wall bushing, respectively, to achieve surface contact connection between the cable side, the limiter, and the grounding side. Compared with traditional point contact wiring, the contact resistance is smaller, and it is not easy to overheat when a large current passes through, thus avoiding grounding failure caused by loose connection or burning.

[0015] The voltage limiter is directly connected to the upper and lower connecting terminal blocks, forming a fast overvoltage response circuit. When the cable shield / armor layer generates an excessive induced voltage, or encounters lightning strikes or operational overvoltages, the voltage limiter can be turned on instantaneously, discharging the overvoltage energy to the ground through the lower connecting terminal block, the lower wall bushing, and the grounding lead, effectively preventing the cable outer sheath insulation from breaking down and ensuring the safe operation of the cable line.

[0016] The layout of three upper wall bushings and one lower wall bushing in this solution is clear, corresponding to the independent wiring positions of the three-phase cables. During subsequent operation and maintenance, the connection points of the faulty phase can be quickly located. The modular connection between the upper and lower connection terminal boards and the voltage limiter also facilitates the replacement of faulty components (such as the voltage limiter) without disassembling the entire grounding box, reducing maintenance difficulty and downtime.

[0017] Furthermore, the limiting unit includes a base plate, a positioning plate is connected to the top of the base plate, a sliding block is slidably fitted on the base plate, a pressing block is connected to the end of the sliding block facing the positioning plate, the limiting groove includes a first limiting groove and a second limiting groove, the first limiting groove and the second limiting groove are respectively opened on the side of the positioning plate and the pressing block facing each other, and the base plate is provided with a driving component for driving the sliding block to slide and press the cable.

[0018] Beneficial effects: In this solution, the first limiting groove of the positioning plate and the second limiting groove of the clamping block are aligned and fit together to form a complete limiting space. The cable (braided lead end) is clamped between the two grooves, achieving all-round limiting in all directions. Compared with the traditional single guiding structure, it can effectively prevent the cable from shifting or twisting laterally due to vibration, self-weight or external force, ensuring that the cable end and the terminal of the upper wall bushing are always accurately aligned, avoiding stress concentration or poor contact at the connection point due to offset, and ensuring the stable conduction of the grounding circuit.

[0019] The first and second limiting grooves are designed to face each other, and their groove shape can be adapted to the outline of the cable (or braided tape) (such as an arc groove). When clamped, they form surface contact rather than point pressure, which can increase the fixing friction and avoid excessive local pressure that could damage the outer sheath of the cable or break the internal conductor. They are especially suitable for fixing flexible conductors such as braided tape, thus extending the service life of the cable.

[0020] The sliding block slides with the base plate. The sliding block is driven to move closer to or away from the positioning plate by the driving component. The clamping distance of the first and second limit slots can be flexibly adjusted. It can be adapted to braided tapes of different cross sections of single core cables of 35kV and below, and can also be compatible with cable lead-out ends of different outer diameters. There is no need to customize a special limit structure for specific cable specifications, which greatly improves the product versatility of the grounding box and reduces production and inventory costs.

[0021] In addition, the limiting groove is specially designed for the soft and loose characteristics of braided tape. The bidirectional clamping can compact and fix the loose ends of the braided tape, preventing the fibers from falling off and the conductor from being exposed during the connection process. This not only ensures the reliability of the connection with the terminal block of the wall bushing, but also prevents the exposed conductor from short-circuiting with the box, making up for the shortcomings of traditional limiting structures in fixing flexible conductors.

[0022] Furthermore, a fixed plate is connected to the top end of the base plate away from the positioning plate. The driving component is located between the fixed plate and the sliding block. The driving component includes a rotating plate that rotatably engages with the base plate. The rotating plate has a parallelogram structure. Rotating the rotating plate allows its end face to contact and push the sliding block toward the positioning plate, thereby pressing the clamping block against the cable passing through the limiting groove. An elastic element is provided between the positioning plate and the sliding block.

[0023] Beneficial effects: The rotating plate adopts a parallelogram structure, which, together with the base plate, forms a lever-driven mechanism. The parallelogram structure can convert rotational force into lateral thrust through changes in the rotation angle. Construction workers only need to gently rotate the rotating plate to push the sliding block towards the positioning plate through its end face, thereby achieving cable clamping. The operation is labor-saving and has high pressurization efficiency, making it especially suitable for one-handed operation in confined spaces.

[0024] The elastic element between the positioning plate and the sliding block can automatically push the sliding block away from the positioning plate after the plate is reversed, so that the first limit groove and the second limit groove are automatically separated. The cable can be quickly put in or taken out without manually pulling the sliding block, which greatly improves the loading and unloading efficiency during installation and maintenance, and is especially suitable for batch construction or frequent maintenance scenarios.

[0025] Furthermore, both ends of the rotating plate are curved surfaces.

[0026] Beneficial effects: In this solution, the contact between the arc surfaces at both ends of the rotating plate and the end face of the sliding block and the inner side of the fixed plate is a smooth transition from line contact to surface contact. Compared with the hard contact at the ends of the flat plate, the arc surfaces can significantly reduce the frictional resistance during rotation, making it smoother and less strenuous for operators to operate.

[0027] In addition, when the elastic element pushes the sliding block to reset and drives the rotating plate to reverse, the arc surface can buffer the impact force during the reset process, avoid rigid collision between the flat end of the rotating plate and the fixed plate and sliding block, reduce component vibration and fatigue damage, reduce noise during reset, and improve the stability of the structure operation.

[0028] Furthermore, the rotating plate has a strip-shaped hole, and the rotating plate is also provided with an upper limit block, a rotating rod and a lower limit block. The bottom end of the upper limit block and the top end of the lower limit block abut against the top and bottom of the rotating plate respectively, and the lower limit block is fixedly connected to the base plate. One end of the rotating rod is connected to the upper limit block, and the other end of the rotating rod is rotatably engaged with the lower limit block. The two side walls of the strip hole are provided with slots, and the two sides of the rotating rod are connected to driving blocks. The two driving blocks are respectively inserted into the slots on both sides of the strip hole and slide in cooperation with the slots.

[0029] Beneficial effects: In this solution, the drive blocks on both sides of the rotating rod are embedded in the slots on both sides of the strip hole to form a two-way embedded sliding fit. This structure can ensure that during the rotation of the rotating rod, the drive blocks can drive the rotating plate to rotate, thereby achieving the purpose of pushing the sliding block to slide.

[0030] Furthermore, a handle is connected to one side of the upper limit block.

[0031] Beneficial effect: The handle provides a gripping point for the operator, making it easier to drive the rotating plate to rotate.

[0032] Furthermore, the side of the sliding block facing the rotating plate is stepped, and there is an inclined surface between the lower horizontal surface and the top surface of the sliding block. A first abutment is fixed on the lower horizontal surface of the sliding block, and one end of the first abutment is in contact with the inclined surface. A second abutment is fixed on the top surface of the fixed plate, and the rotating plate is located between the first abutment and the second abutment.

[0033] Beneficial effects: The first abutment plate fits against the inclined surface of the sliding block and is fixed to the lower horizontal plane, forming a triangular support structure of the inclined surface and the abutment plate. This not only enhances the rigidity of the stepped structure of the sliding block (avoiding deformation of the inclined surface due to long-term stress), but also directly bears the lateral thrust of the rotating plate, distributing the load to the entire lower area of ​​the sliding block, rather than concentrating it at the sliding fit between the sliding block and the base plate, reducing the wear of the sliding block and extending the service life of the sliding fit structure.

[0034] The rotating plate abuts against the first and second abutments. Compared to the rotating plate directly contacting the sliding block and the fixed plate, the areas of the first and second abutments are smaller than those of the sliding block and the fixed plate. The contact between the abutments and the rotating plate is a local point / line contact, and the remaining areas form a clearance space. During the rotation, the edges and end faces of the rotating plate can move freely within the clearance space, avoiding large-area friction or rigid interference with the stepped surface of the sliding block and the top surface of the fixed plate. Especially when the rotating plate rotates at a large angle, the clearance space can accommodate the deformation or displacement deviation of the rotating plate, ensuring that the rotation process is smooth and unobstructed, and the operation is smoother and less strenuous.

[0035] Furthermore, a guide rod is connected between the positioning plate and the fixing plate, the guide rod passes through the sliding block, the elastic element is a spring, the spring is sleeved on the outside of the guide rod, and the two ends of the spring are respectively connected to the positioning plate and the sliding block.

[0036] Beneficial effects: The guide rod serves as a guide for the sliding block, ensuring its precise sliding movement. The guide rod strictly limits the direction of movement of the sliding block, allowing it to only move horizontally along the guide rod, preventing lateral offset, twisting, or tilting of the sliding block during force application. This ensures that the clamping block and the positioning plate's limiting groove are always aligned, preventing cable clamping from shifting or tilting, and ensuring precise alignment of the cable end with the upper wall bushing terminal, thus avoiding increased contact resistance or grounding failure.

[0037] Furthermore, a boss is provided on the side of the positioning plate facing the sliding block, and the boss and the top of the positioning plate form a stepped structure, with the bottom of the pressing block located at the top of the boss.

[0038] Beneficial effects: In this design, the top of the boss provides a stable support surface for the clamping block, and also serves as a guide for the movement of the clamping block, ensuring the accuracy of the clamping block's movement position.

[0039] Furthermore, the bottom of the limiting unit is vertically connected to multiple support columns, and the bottom end of the support columns is connected to the top of the box.

[0040] Beneficial effects: In this solution, the limiting unit is supported above the box by the support column, so that there is a certain distance between the limiting unit and the box. This makes it convenient to install the wall-penetrating pipe on the top of the box, and provides installation space for the connection between the end of the cable and the wall-penetrating pipe, which is convenient for operation.

[0041] Furthermore, both ends of the rotating plate are provided with mounting grooves, and limit beads slide in the mounting grooves. A spring connects the limit beads to the mounting grooves. The ends of the first abutment plate and the second abutment plate are provided with grooves that engage with the limit beads. When the rotating plate rotates to the state where the clamping block clamps the cable, the limit beads are engaged in the grooves.

[0042] Beneficial effects: In this design, when the limiting bead engages in the groove, it locks the rotating plate, further enhancing the stability of the rotating plate after it reaches the designated position. This avoids the instability caused by relying solely on frictional resistance between the rotating plate and the first and second abutments, which can easily lead to unlocking and resetting due to external forces. This design further improves the stability of the rotating plate. When the rotating plate pushes the sliding block towards the positioning plate, thereby causing the clamping block to approach the positioning plate and press against the cable, it maintains a pressed state. The rotating plate is unlikely to rotate on its own at this time; it can only be rotated when the operator operates the handle. This effectively ensures the stable locking state of the rotating plate, thus guaranteeing the stable pressing of the cable by the clamping block. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an embodiment of a cable grounding box according to the present invention; Figure 2 This is a top view of the limiting unit in an embodiment of a cable grounding box according to the present invention; Figure 3 This is a partial sectional view of the limiting unit in one embodiment of a cable grounding box according to the present invention, taken from the side. Figure 4 This is a partial sectional view of the limiting unit in another embodiment of the cable grounding box of the present invention, taken from the side. Figure 5 This is a schematic diagram showing the state in which the limiting unit pushes the clamping block to slide towards the positioning plate in one embodiment of a cable grounding box according to the present invention; Figure 6 This is a top view of the limiting unit in another embodiment of a cable grounding box according to the present invention; Figure 7 for Figure 6 A magnified view of a portion of point A in the middle.

[0044] The attached diagram shows the markings and corresponding component names: 1. Housing; 2. Voltage limiter; 3. Upper connecting terminal block; 4. Lower connecting terminal block; 5. Upper through-wall sleeve; 6. Limiting unit; 61. Base plate; 62. Positioning plate; 620. Boss; 63. Fixing plate; 64. Sliding block; 641. Inclined surface; 65. First abutment plate; 66. Second abutment plate; 67. Rotating plate; 670. Strip hole; 671. Arc surface; 68. Guide rod; 69. Spring; 6 10. Slot; 611. Upper limit block; 612. Handle; 613. Lower limit block; 614. Rotating rod; 615. Drive block; 616. Clamping block; 617. Support block; 618. First limit groove; 619. Second limit groove; 7. Support column; 8. Cold-pressed terminal; 9. Braided strap; 10. Through-wall sleeve; 11. Grounding lead wire; 12. Groove; 13. Mounting groove; 14. Limiting bead. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0046] like Figure 1 As shown, this embodiment provides a cable grounding box, including a box body 1. Inside the box body 1, there are an upper connecting terminal plate 3, a lower connecting terminal plate 4 and a voltage limiter 2. The upper connecting terminal plate 3 is located at the upper part of the box body 1, and the lower connecting terminal plate 4 is located at the lower part of the box body 1. The voltage limiter 2 is connected and conductive to the upper connecting terminal plate 3 and the lower connecting terminal plate 4. Three upper wall bushings 5 ​​are connected to the top of the enclosure 1, and one lower wall bushing 10 is connected to the bottom of the enclosure 1. The upper wall bushings 5 ​​and the lower wall bushing 10 are respectively connected to the upper connecting terminal plate 3 and the lower connecting terminal plate 4. In this embodiment, the three upper wall bushings 5 ​​are used to directly connect to the braided strips 9 (three phases) led out from the armor layer and shielding layer of the 35kV and below single-core power cable. The lower wall bushing 10 has a grounding lead 11 connected to the terminal at the lower end, which is connected to the main grounding grid. In this embodiment, the three upper wall bushings 5 ​​are securely connected to the three corresponding terminals on the upper connecting terminal plate 3. In this embodiment, three voltage limiters 2 are provided, each corresponding to one of the three upper wall bushings 5. One end of each voltage limiter 2 is connected to the three corresponding phase terminals on the upper connecting terminal plate 3, and the other end of each voltage limiter 2 is connected to the lower connecting terminal plate 4.

[0047] In this embodiment, a limiting unit 6 is also connected to the top of the box 1. In this embodiment, multiple support columns 7 are vertically connected to the bottom of the limiting unit 6. The bottom end of the support column 7 is connected to the top of the box 1. In this embodiment, four support columns 7 are provided. The four support columns 7 are distributed in a rectangular shape, and the support columns 7 are detachably connected to the top of the box 1 by bolts, which facilitates assembly and disassembly.

[0048] In this embodiment, the limiting unit 6 is provided with a limiting groove for the cable to pass through, and the end of the cable (braided strip 9) is connected to the terminal of the upper wall sleeve 5.

[0049] In this embodiment, a cold-pressed terminal 8 is pressed onto the end of the braided tape 9, and the cold-pressed terminal 8 is fixed to the terminal of the upper through-wall sleeve 5.

[0050] In one embodiment, combined Figure 2 As shown, the limiting unit 6 includes a base plate 61, a positioning plate 62 connected to the top of the base plate 61, and a sliding block 64 slidably fitted on the base plate 61. A clamping block 616 is connected to the end of the sliding block 64 facing the positioning plate 62. Figure 3 As shown, in this embodiment, a support block 617 is welded, bolted, or integrally formed on the side of the sliding block 64 facing the positioning plate 62 and located on its upper part. The pressing block 616 is located at the top of the support block 617 and is detachably fixed to the support block 617 by bolts, which facilitates disassembly and installation.

[0051] Combination Figure 2 As shown, in this embodiment, the limiting groove includes a first limiting groove 618 and a second limiting groove 619. The first limiting groove 618 and the second limiting groove 619 are respectively opened on the side of the positioning plate 62 and the pressing block 616 facing each other. In this embodiment, the first limiting groove 618 and the second limiting groove 619 are both semi-circular grooves. The bottom plate 61 is provided with a driving member for driving the sliding block 64 to slide so that the pressing block 616 presses the cable.

[0052] In one embodiment, such as Figure 2 and Figure 3 As shown, a fixing plate 63 is connected to the top end of the base plate 61 away from the positioning plate 62. In this embodiment, the fixing plate 63 is welded to the base plate 61, integrally formed, or bolted. The driving component is located between the fixing plate 63 and the sliding block 64. In this embodiment, the driving component includes a rotating plate 67, which is rotatably engaged with the base plate 61. The rotating plate 67 has a parallelogram structure. Rotating the rotating plate 67 can cause the end face of the rotating plate 67 to contact and push the sliding block 64 to move towards the positioning plate 62, thereby pressing the clamping block 616 to press the cable passing through the limiting groove. In this embodiment, an elastic element is provided between the positioning plate 62 and the sliding block 64.

[0053] In one embodiment, such as Figure 2 As shown, both ends of the rotating plate 67 are arc surfaces 671, and the arc surfaces 671 are outwardly convex circular arc surfaces 671.

[0054] In one embodiment, such as Figure 2 As shown, a strip-shaped hole 670 is provided on the rotating plate 67, such as... Figure 3 As shown, the rotating plate 67 is also provided with an upper limit block 611, a rotating rod 614, and a lower limit block 613. The bottom end of the upper limit block 611 and the top end of the lower limit block 613 abut against the top and bottom of the rotating plate 67, respectively. Both the upper limit block 611 and the lower limit block 613 are circular, and the diameters of the upper limit block 611 and the lower limit block 613 are larger than the width of the strip hole 670, so that the upper limit block 611 and the lower limit block 613 can be located on both sides of the rotating plate 67, respectively, and play a supporting role for the rotating plate 67.

[0055] The lower limit block 613 is fixedly connected to the base plate 61. In this embodiment, the lower limit block 613 and the base plate 61 are fixed by screws or other means, which are not specifically limited here. One end of the rotating rod 614 is fixedly connected to the upper limit block 611 by threads or screws, and the other end of the rotating rod 614 is rotatably engaged with the lower limit block 613. like Figure 3 As shown, slots 610 are provided on both sides of the strip hole 670, and driving blocks 615 are connected to both sides of the rotating rod 614. The driving blocks 615 are fixed to the rotating rod 614 by screws, welding or bonding. The two driving blocks 615 are respectively inserted into the slots 610 on both sides of the strip hole 670 and slide in cooperation with the slots 610.

[0056] like Figure 2As shown, in this embodiment, a handle 612 is connected to one side of the upper limit block 611. The handle 612 is tilted upwards, and in this embodiment, the handle 612 is fixed to one side of the upper limit block 611 by welding, bonding, or other means.

[0057] In one embodiment, such as Figure 3 As shown, the side of the sliding block 64 facing the rotating plate 67 is stepped. There is an inclined surface 641 between the lower horizontal surface of the sliding block 64 and its top surface. A first abutment 65 is fixed on the lower horizontal surface of the sliding block 64. One end of the first abutment 65 is in contact with the inclined surface 641. A second abutment 66 is fixed on the top surface of the fixed plate 63. The first abutment 65 and the second abutment 66 are both centrally located. The rotating plate 67 is located between the first abutment 65 and the second abutment 66. The arrangement of the first abutment 65 and the second abutment 66 can form clearance spaces between the sliding block 64 and the fixed plate 63, respectively, which facilitates the smooth rotation of the rotating plate 67.

[0058] In one embodiment, such as Figure 2 and Figure 3 As shown, a guide rod 68 is connected between the positioning plate 62 and the fixing plate 63. In this embodiment, two guide rods 68 are provided, which are arranged parallel to each other and pass through the sliding block 64. The elastic element in this embodiment is a spring 69, which is sleeved on the outside of the guide rod 68, and the two ends of the spring 69 are respectively connected to the positioning plate 62 and the sliding block 64.

[0059] In one embodiment, such as Figure 4 As shown, a boss 620 is provided on the side of the positioning plate 62 facing the sliding block 64. The boss 620 and the top of the positioning plate 62 form a stepped structure. The bottom of the clamping block 616 is located on the top of the boss 620 and can slide on the top of the boss 620. The boss 620 is configured to support the clamping block 616 and allow the clamping block 616 to slide at a certain horizontal height, ensuring the stability and accuracy of the movement of the clamping block 616.

[0060] In one embodiment, such as Figure 6 and Figure 7 As shown, in this embodiment, mounting grooves 13 are provided at both ends of the rotating plate 67 with the longest distance. Limiting beads 14 are slidably fitted in the mounting grooves 13. A spring is connected between the limiting beads 14 and the mounting grooves 13. When the spring is not compressed, one end of the limiting beads 14 extends out of the mounting grooves 13. In this embodiment, grooves 12 that engage with limiting beads 14 are provided at the ends of the first abutment plate 65 and the second abutment plate 66. When the rotating plate 67 is rotated so that the two ends of the longest distance of the rotating plate 67 abut against the first abutment plate 65 and the second abutment plate 66 respectively, the limiting beads 14 at both ends of the rotating plate 67 can be engaged in the grooves 12 of the first abutment plate 65 and the second abutment plate 66. When the rotating plate 67 rotates to the state where the clamping block 616 clamps the cable, the limiting beads 14 are engaged in the grooves 12, thereby locking the rotating plate 67. In this way, when the rotating plate 67 pushes the sliding block 64 to move towards the positioning plate 62, thereby driving the clamping block 616 to approach the positioning plate 62 and clamp the cable, the clamping state can be maintained. The rotating plate 67 is not easy to rotate on its own. The rotating plate 67 can only be rotated when the operator operates the handle. This effectively ensures the stable state of the rotating plate 67, thereby ensuring that the clamping block 616 stably clamps the cable.

[0061] In addition, when the limiting bead 14 is inserted into the groove 12, it will produce a noticeable "sticking sensation" and a slight sound, providing operators with intuitive tactile and auditory feedback. No additional measuring tools are needed to confirm that the rotation is in place. Even in narrow spaces or cable trenches with insufficient light, precise operations can be completed quickly, greatly reducing the construction threshold for non-professionals.

[0062] The specific implementation process is as follows: like Figure 2 As shown, when the two ends of the shortest distance on the rotating plate 67 abut against the first abutment plate 65 and the second abutment plate 66 respectively, the sliding block 64, under the action of the spring 69, drives the pressing block 616 away from the positioning plate 62, thereby releasing the cable. This facilitates the insertion or removal of the cable in the limiting groove. When the cable is inserted into the limiting groove, and the cold-pressed terminal 8 at the end of the cable (braided strap 9) is connected to the upper through-wall sleeve 5, as... Figure 5 As shown, by rotating the rotating plate 67, the two ends of the longest distance of the rotating plate 67 abut against the first abutment plate 65 and the second abutment plate 66 respectively, thereby causing the sliding block 64 to move towards the positioning plate 62, which in turn drives the pressing block 616 to approach the positioning plate 62 and press the cable. This protects the cable, and the cable is less likely to sag due to its own weight or be pulled by external forces, causing the connection part with the terminal of the upper through-wall sleeve 5 to be subjected to concentrated force or fall off.

[0063] The existing cable grounding boxes are all cable bottom entry, suitable for 66kV and above single-core power cable terminals. For 66kV and above cable terminals, one grounding cable can be installed from the side of the cable head, so the existing cable grounding boxes can be used for installation. Due to the structure of the cable terminal, for 35kV and below single-core power cable terminals, only one braided tape is led out from the armor layer and shielding layer during construction, which cannot be adapted to the wiring method of the existing cable grounding boxes. At present, the construction site usually leads out the braided tape and then binds it with the 10kV grounding cable on site and insulates it, which cannot guarantee reliable fixation and brings inconvenience to construction.

[0064] The cable grounding box of this invention allows the braided strap 9 to be directly connected to the upper wall bushing 5, and the lower wall bushing 10 to be directly connected to the main grounding grid via the grounding down conductor 11. This greatly increases the reliability of the connection and the convenience of construction, and also improves the aesthetics of the site. The new cable grounding box has significantly fewer installation accessories, simplifies on-site installation, and reduces the thickness of the box body 1, making it suitable for cable grounding needs in areas with limited space (such as the bottom of switch cabinets).

[0065] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cable grounding box, comprising a box body, characterized in that, The enclosure is internally connected to an upper terminal block, a lower terminal block, and a voltage limiter. The upper terminal block is located at the top of the enclosure, and the lower terminal block is located at the bottom of the enclosure. The voltage limiter is connected and conductive to the upper terminal block and the lower terminal block. The top of the box is connected to three upper through-wall sleeves, and the bottom of the box is connected to one lower through-wall sleeve. The upper through-wall sleeve and the lower through-wall sleeve are respectively connected to the upper connecting terminal plate and the lower connecting terminal plate. The top of the enclosure is also connected to a limiting unit, which has a limiting groove for the cable to pass through. The end of the cable is connected to the terminal of the upper through-wall sleeve.

2. A cable grounding box according to claim 1, characterized in that, The limiting unit includes a base plate, a positioning plate connected to the top of the base plate, a sliding block slidably fitted on the base plate, a pressing block connected to the end of the sliding block facing the positioning plate, and a limiting groove including a first limiting groove and a second limiting groove, the first limiting groove and the second limiting groove being respectively opened on the side of the positioning plate and the pressing block facing each other. The base plate is provided with a driving component for driving the sliding block to slide so that the pressing block presses the cable.

3. A cable grounding box according to claim 2, characterized in that, A fixed plate is connected to the top end of the base plate away from the positioning plate. The driving component is located between the fixed plate and the sliding block. The driving component includes a rotating plate that is rotatably engaged with the base plate. The rotating plate has a parallelogram structure. Rotating the rotating plate allows its end face to contact and push the sliding block towards the positioning plate, thereby pressing the clamping block against the cable passing through the limiting groove. An elastic element is provided between the positioning plate and the sliding block.

4. A cable grounding box according to claim 3, characterized in that, Both ends of the rotating plate are curved surfaces.

5. A cable grounding box according to claim 3, characterized in that, The rotating plate has a strip-shaped hole. The rotating plate is also provided with an upper limit block, a rotating rod and a lower limit block. The bottom end of the upper limit block and the top end of the lower limit block abut against the top and bottom of the rotating plate, respectively. The lower limit block is fixedly connected to the base plate. One end of the rotating rod is connected to the upper limit block and the other end of the rotating rod is rotatably engaged with the lower limit block. The two side walls of the strip hole are provided with slots, and the two sides of the rotating rod are connected to drive blocks. The two drive blocks are respectively inserted into the slots on both sides of the strip hole and slide in cooperation with the slots.

6. A cable grounding box according to claim 5, characterized in that, A handle is connected to one side of the upper limit block.

7. A cable grounding box according to claim 5, characterized in that, The sliding block has a stepped shape on the side facing the rotating plate. There is an inclined surface between the lower horizontal surface and the top surface of the sliding block. A first abutment is fixed on the lower horizontal surface of the sliding block. One end of the first abutment is in contact with the inclined surface. A second abutment is fixed on the top surface of the fixed plate. The rotating plate is located between the first abutment and the second abutment.

8. A cable grounding box according to claim 3, characterized in that, A guide rod is connected between the positioning plate and the fixing plate. The guide rod passes through the sliding block. The elastic element is a spring. The spring is sleeved on the outside of the guide rod, and the two ends of the spring are respectively connected to the positioning plate and the sliding block.

9. A cable grounding box according to claim 3, characterized in that, The positioning plate has a boss on the side facing the sliding block, and the boss and the top of the positioning plate form a stepped structure. The bottom of the pressing block is located on the top of the boss.

10. A cable grounding box according to claim 7, characterized in that, Both ends of the rotating plate are provided with mounting grooves, and limit beads slide in the mounting grooves. A spring connects the limit beads to the mounting grooves. The ends of the first abutment plate and the second abutment plate are provided with grooves that engage with the limit beads. When the rotating plate rotates to the state where the clamping block clamps the cable, the limit beads are engaged in the grooves.

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