A cable branch box cable entry adjustable seal structure

Abstract

The application relates to the technical field of cable branch boxes, and discloses a cable branch box cable inlet adjustable sealing structure, which comprises a box body, the box body is provided with a cable inlet, a dehumidification air supply unit is arranged in the box body, the dehumidification air supply unit comprises a semiconductor refrigerating fin and a micro air pump, the semiconductor refrigerating fin is provided with a cold end and a hot end, the cold end faces the box body, and the air inlet end of the micro air pump is arranged adjacent to the cold end; a sealing execution unit is arranged at the cable inlet, the sealing execution unit comprises an inlet base, a compression nut and a hollow elastic sealing body. Dry air generated by the dehumidification air supply unit is injected into the air bag chamber of the hollow elastic sealing body through the air guide pipe, the sealing body can be uniformly expanded from the inside, irregular gaps between cables and threading holes and between the cables can be adaptively filled, and a better air-tight effect than simple mechanical compression can be achieved.

Description

Technical Field

[0001] This invention relates to the field of cable branch box technology, specifically to an adjustable sealing structure for the cable inlet of a cable branch box. Background Technology

[0002] Cable distribution boxes, as the final-level equipment used for cable branching or switching in power distribution networks, are widely used in outdoor environments. Cables enter the box through cable inlets on the box wall panels, and the sealing performance of these inlets directly affects the safe operation of the electrical equipment inside. Currently, the sealing of cable inlets mainly employs the following methods: First, a rubber sealing ring with a fixed inner diameter is wrapped between the cable's outer wall and the inlet, achieving a seal through an interference fit; second, a cable gland is used, where tightening the compression nut compresses the internal elastic sealing ring, causing it to radially contract and tightly grip the cable; third, fireproof putty, sealing putty, or other fillers are used to fill and seal the inlet; fourth, a modular through-hole sealing system is used, combining different specifications of variable-diameter sealing modules to match the cable diameter. These methods, to a certain extent, solve the sealing problem of single cable entry.

[0003] However, existing technologies have significant shortcomings in practical applications. First, the aforementioned sealing methods are all passive seals, relying on the elastic deformation of the material itself or the physical barrier of the cured filler to block external moisture and dust. Once the sealing material deteriorates due to aging, hardening, shrinkage, or micro-cracks during long-term outdoor operation, the sealing effect irreversibly declines. Furthermore, this process lacks effective online monitoring methods, making it difficult for maintenance personnel to detect and address issues promptly; they often only become aware of the problem after equipment failure. Second, when multiple cables of varying thicknesses share a single inlet, the irregular triangular gaps between the cables make it difficult for a fixed-diameter sealing ring or a single-specification gland to completely fill these gaps, easily leaving leakage channels. Third, once traditional filler sealing methods are completed, subsequent replacement or addition of cables requires removing the original filler and redoing the process, which is cumbersome, labor-intensive, and results in high maintenance costs. Summary of the Invention

[0004] In view of the shortcomings of the existing cable inlet sealing structure mentioned in the background art during use, the present invention provides an adjustable sealing structure for the cable inlet of a cable branch box, which has the advantages of active dehumidification and pneumatic enhanced sealing working in synergy, online leakage self-diagnosis and emergency positive pressure maintenance, and adaptive sealing of gaps between multiple cable specifications, thus solving the technical problems mentioned in the background art.

[0005] This invention provides the following technical solution: an adjustable sealing structure for the cable inlet of a cable branch box, comprising a box body having a cable inlet; a dehumidification and air supply unit is provided inside the box body, the dehumidification and air supply unit comprising a semiconductor cooling chip and a micro air pump, the semiconductor cooling chip having a cold end and a hot end, the cold end facing the inside of the box body, and the air inlet of the micro air pump being located adjacent to the cold end; a sealing execution unit is provided at the cable inlet, the sealing execution unit comprising an inlet base, a clamping nut, and a hollow elastic sealing body, the inlet base being fixed to the box body and having a conical inner hole, the hollow elastic sealing body being frustoconical in shape and having an air bladder chamber inside, the hollow elastic sealing body having multiple wire through holes, and an air valve communicating with the air bladder chamber being provided on the large end face sidewall of the hollow elastic sealing body; It also includes an air guide tube and a leak detection unit. One end of the air guide tube is connected to the air outlet of the micro air pump, and the other end is connected to the air valve. The leak detection unit includes a first humidity sensor, a second humidity sensor, and a controller. The first humidity sensor is located inside the inlet base, the second humidity sensor is located inside the housing, and the controller is electrically connected to the first humidity sensor, the second humidity sensor, the semiconductor cooling chip, and the micro air pump.

[0006] Preferably, a heat sink is attached to the hot end of the semiconductor cooling chip, and the heat sink extends outside the housing.

[0007] Preferably, a water-collecting heat sink is attached to the cold end of the semiconductor cooling chip, and the water-collecting heat sink is connected to a drain pipe, which leads out of the box.

[0008] Preferably, the miniature air pump is a miniature silent air pump.

[0009] Preferably, the hollow elastic seal is made of highly elastic rubber or silicone material.

[0010] Preferably, the controller is a microcontroller or a programmable logic controller.

[0011] Preferably, the controller is also electrically connected to a communication module.

[0012] Preferably, the controller has a preset comparison logic. When the humidity value detected by the first humidity sensor is lower than the humidity value detected by the second humidity sensor and the difference exceeds a preset threshold, the controller determines that the hollow elastic seal has leaked.

[0013] The present invention has the following beneficial effects: 1. This invention injects dry air generated by the dehumidification air supply unit into the air chamber of the hollow elastic seal through the air guide pipe, which enables the seal to expand uniformly from the inside and adaptively fill the irregular gaps between the cable and the wire hole and between the cables, achieving a better airtight effect than simple mechanical compression.

[0014] 2. By introducing an air seal barrier formed by slightly positive pressure dry air inside the airbag chamber, the present invention can ensure that the internal air pressure at the cable inlet is always higher than that of the external environment, thus physically and actively preventing humid air, dust and tiny insects from invading the interior of the box along the cable surface.

[0015] 3. By comparing the readings of the first humidity sensor and the second humidity sensor in real time through the leakage detection unit, this invention can accurately distinguish between internal gas leakage and external moisture intrusion by utilizing the unique physical characteristic that leaked dry air causes an abnormal decrease in local humidity, thus achieving online self-diagnosis of the integrity of the seal.

[0016] 4. This invention automatically switches the micro air pump to continuous operation mode after the controller detects a leak in the sealing body. It can continuously replenish dry air to the airbag chamber to maintain positive pressure inside, thus providing maintenance personnel with a valuable window of time for maintenance in the event of a fault and preventing moisture from immediately invading and damaging the equipment.

[0017] 5. By integrating the dehumidification module and the sealing module into a closed-loop system, the present invention enables the dry air generated by dehumidification to become the power source for enhanced sealing. The enhanced sealing, in turn, significantly reduces the rate of external moisture intrusion, thereby reducing the frequency of start-up and shutdown of the dehumidification module and achieving the dual effects of energy saving and extending the life of core components. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the cable branch box of the present invention; Figure 2 For the present invention Figure 2 Partial schematic diagram of the structure at point A; Figure 3 This is a schematic diagram of the air-filling operation of the sealing execution unit structure of the present invention.

[0019] In the diagram: 1. Dehumidification and air supply unit; 11. Semiconductor cooling chip; 111. Water collection and heat dissipation fin; 12. Miniature air pump; 2. Sealing actuator; 21. Inlet base; 22. Compression nut; 23. Hollow elastic sealing body; 231. Wiring hole; 232. Airbag chamber; 233. Valve nozzle; 3. Air guide tube; 4. Leakage detection unit; 41. First humidity sensor; 42. Second humidity sensor; 43. Controller. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 An adjustable sealing structure for the cable inlet of a cable branch box includes a box body, a dehumidification and air supply unit 1 disposed inside the box body, a sealing execution unit 2 disposed at the cable inlet, an air duct 3 connecting the two, and a leakage detection unit 4 for intelligent monitoring.

[0022] The enclosure has a cable inlet for cables to pass through. A dehumidifying air supply unit 1 is fixedly installed inside the enclosure to generate dry, clean air and serve as a pressurized air source. This dehumidifying air supply unit 1 includes a thermoelectric cooler 11 and a miniature air pump 12. The thermoelectric cooler 11 has a cold end and a hot end, with the cold end facing inwards and the hot end facing outwards. It utilizes the Peltier effect to achieve directional heat transfer from the cold end to the hot end when energized. The air inlet of the miniature air pump 12 is positioned adjacent to the cold end of the thermoelectric cooler 11 via a bracket or pipe, ensuring that it preferentially draws in low-temperature, dry air after condensation and dehumidification. The air outlet of the miniature air pump 12 is connected to one end of the air guide pipe 3.

[0023] In a preferred embodiment, a set of heat sinks is attached to the hot end of the thermoelectric cooler 11. These heat sinks extend beyond the cabinet through the wall panel to efficiently dissipate heat generated during dehumidification to the external environment, ensuring cooling efficiency. Furthermore, a water-collecting heat sink 111 is attached to the cold end of the thermoelectric cooler 11. This water-collecting heat sink 111 is made of aluminum alloy with good thermal conductivity, and its surface is hydrophilic to facilitate the collection and dripping of condensate droplets. A drain pipe is connected to the bottom of the water-collecting heat sink 111, which extends through the bottom of the cabinet to the outside to drain condensate promptly and prevent water accumulation inside the cabinet.

[0024] Please see Figure 2-3As a preferred embodiment, to reduce operating noise and vibration, a miniature silent air pump is selected for the miniature air pump 12. The sealing actuator 2 is located at the cable inlet of the housing, specifically including an inlet base 21, a clamping nut 22, and a hollow elastic sealing body 23. The inlet base 21 is fixed to the housing wall panel by a flange or threaded connection, and the inner wall of its central through hole is machined into an inner conical surface. The hollow elastic sealing body 23 is generally frustoconical in shape, forming a conical fit with the inner conical surface of the inlet base 21. The hollow elastic sealing body 23 is made of highly elastic rubber or silicone material, which can produce uniform radial contraction or expansion deformation when subjected to external force. Its interior has a surrounding airbag chamber 232 formed by molding or vulcanization process. Multiple through holes 231 for cables to pass through are opened along the axial direction on the sealing body. On the large end face side wall of the hollow elastic sealing body 23, a valve 233 connected to the internal airbag chamber 232 is provided. During installation, the cables pass through the through holes 231, and the clamping nuts 22 are tightened. The end face of the clamping nut 22 pushes against the large end face of the hollow elastic sealing body 23, forcing it to move inward along the inner conical surface of the inlet base 21 and generate radial contraction, thereby providing initial mechanical sealing force. This allows the inner wall of the through hole 231 to initially grip the cable sheath, while the outer wall of the sealing body fits tightly against the inner conical surface of the base. The other end of the air guide tube 3 is tightly inserted into or threaded onto the valve 233, thus constructing a closed gas passage from the outlet of the micro air pump 12 to the airbag chamber 232.

[0025] To enable online diagnosis of the sealing condition, this embodiment also includes a leakage detection unit 4. This leakage detection unit 4 mainly consists of a first humidity sensor 41, a second humidity sensor 42, and a controller 43. The first humidity sensor 41 is installed inside the inlet base 21, with its probe facing the interface between the hollow elastic seal 23 and the cable, used to collect humidity data at this critical sealing interface in real time. The second humidity sensor 42 is installed inside the enclosure in the equipment mounting area, away from the cable inlet, used to collect the overall ambient humidity inside the enclosure. The controller 43 is based on a microcontroller or programmable logic controller. Its signal input terminals are electrically connected to the first humidity sensor 41 and the second humidity sensor 42, respectively, while its control output terminals are electrically connected to the power supply circuits of the semiconductor cooling chip 11 and the micro air pump 12, respectively.

[0026] As a further extension of its functionality, the controller 43 is also electrically connected to a communication module. This communication module can be a 4G / 5G wireless communication module or a wired Ethernet module, used to remotely report the humidity status inside the enclosure, system operating data, and leakage alarm information to the operation and maintenance center or the mobile terminal of the management personnel, realizing unattended intelligent operation and maintenance.

[0027] The method of using (working principle) of this invention is as follows: In use, when the controller 43 detects through the second humidity sensor 42 that the humidity inside the chamber exceeds a preset safety threshold, it determines that there is a risk of condensation inside the chamber. The controller 43 immediately starts the semiconductor cooling chip 11 and the micro air pump 12 simultaneously. On one hand, the cold end of the semiconductor cooling chip 11 cools down rapidly, and the humid and hot air flowing through the water collection heat sink 111 reaches the dew point on the low-temperature surface. The water vapor condenses into water droplets and flows into the drain pipe to be discharged outside the chamber, continuously processing the air inside the chamber into dry air. On the other hand, the air inlet of the micro air pump 12 accurately draws this freshly dehumidified dry air from near the cold end, pressurizes it, and injects it into the air chamber 232 of the hollow elastic sealing body 23 through the air guide pipe 3 and the air valve 233.

[0028] As dry air is continuously injected, the airbag chamber 232 undergoes uniform and controllable volume expansion. This expansion force from the inside out causes the inner wall of the cable hole 231 to adaptively press against the outer sheath of each cable with extremely uniform pressure, achieving a perfect fit regardless of cable thickness and completely sealing the triangular gaps between cables. At the same time, the outer wall of the sealing body is also pressed against the inner conical surface of the inlet base 21 with greater pressure. The expansion force driven by air pressure and the initial mechanical force provided by the clamping nut 22 superimpose to form a reliable "double seal". The continuous micro-positive pressure environment inside the airbag chamber 232 can actively resist the intrusion of external humid air, dust, and tiny insects into the housing from any potential gaps. Here, the dry air generated by the dehumidification module is the power source for the enhanced seal, while the enhanced seal solidifies the dehumidification results, reduces the frequency of start-up and shutdown of the dehumidification module, and extends its service life.

[0029] If the hollow elastic seal 23 develops minor cracks due to long-term outdoor operation or a slight leak due to improper installation, the slightly positive pressure dry air in the airbag chamber 232 will slowly escape from the leak point. Since the escaping gas is extremely dry air that has undergone condensation and dehumidification, its humidity is far lower than the natural air humidity inside and outside the chamber. At this time, the first humidity sensor 41, installed closest to the leak point, will immediately detect this dry airflow, and the humidity value it detects will decrease significantly and unnaturally. Meanwhile, the second humidity sensor 42, located inside the chamber, will detect a relatively stable ambient background humidity value, or it may slowly increase due to moisture intrusion.

[0030] The controller 43 has comparison and judgment logic pre-programmed inside. It reads and calculates the humidity difference between the first humidity sensor 41 and the second humidity sensor 42 in real time. Once the program recognizes a specific abnormal pattern where "the humidity detection value of the first humidity sensor 41 is lower than the humidity detection value of the second humidity sensor 42, and the difference between the two exceeds a preset threshold," the controller 43 determines that a gas leak has occurred in the hollow elastic seal 23. This judgment logic eliminates interference from external environmental moisture intrusion, because if external humid air were to intrude, the reading of the first humidity sensor 41 would necessarily be higher than the reading of the second humidity sensor 42.

[0031] Upon detecting a leak, controller 43 immediately performs two actions: First, it sends a precise alarm message via the communication module stating "Abnormal airtightness at cable inlet, please check" to maintenance personnel; second, it changes the control strategy for the micro air pump 12, switching it from intermittent energy-saving operation mode to continuous operation mode, continuously supplying dry air to the air chamber 232 to compensate for leakage losses and maintain the internal positive pressure environment that plays a decisive role in preventing moisture intrusion. This provides maintenance personnel with a time window for scheduling power outages and repairs, achieving a fully automated closed-loop process for detection, diagnosis, and emergency maintenance.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adjustable sealing structure for the cable inlet of a cable branch box, characterized in that: The device includes a housing with a cable inlet; a dehumidification and air supply unit (1) is installed inside the housing, the dehumidification and air supply unit (1) includes a semiconductor cooling chip (11) and a micro air pump (12), the semiconductor cooling chip (11) has a cold end and a hot end, the cold end faces the inside of the housing, and the air inlet of the micro air pump (12) is located adjacent to the cold end; a sealing actuator (2) is installed at the cable inlet, the sealing actuator (2) includes an inlet The base (21), the clamping nut (22), and the hollow elastic sealing body (23) are provided. The inlet base (21) is fixed to the box and its inner hole is conical. The hollow elastic sealing body (23) is frustoconical and has an airbag chamber (232) inside. The hollow elastic sealing body (23) has multiple through holes (231). The large end face side wall of the hollow elastic sealing body (23) is provided with a valve (233) that communicates with the airbag chamber (232). It also includes an air guide tube (3) and a leak detection unit (4). One end of the air guide tube (3) is connected to the air outlet of the micro air pump (12), and the other end is connected to the valve (233). The leak detection unit (4) includes a first humidity sensor (41), a second humidity sensor (42), and a controller (43). The first humidity sensor (41) is located inside the inlet base (21), and the second humidity sensor (42) is located inside the housing. The controller (43) is electrically connected to the first humidity sensor (41), the second humidity sensor (42), the semiconductor cooling chip (11), and the micro air pump (12).

2. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: A heat sink is attached to the hot end of the semiconductor cooling chip (11), and the heat sink extends outside the housing.

3. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: A water-collecting heat sink (111) is attached to the cold end of the semiconductor cooling chip (11), and the water-collecting heat sink (111) is connected to a drain pipe, which leads out of the box.

4. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: The miniature air pump (12) is a miniature silent air pump.

5. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: The hollow elastic seal (23) is made of highly elastic rubber or silicone material.

6. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: The controller (43) is a microcontroller or a programmable logic controller.

7. The adjustable sealing structure for the cable inlet of a cable branch box according to claim 1, characterized in that: The controller (43) is also electrically connected to a communication module.

8. An adjustable sealing structure for the cable inlet of a cable branch box according to any one of claims 117, characterized in that: The controller (43) has a preset comparison logic. When the humidity value detected by the first humidity sensor (41) is lower than the humidity value detected by the second humidity sensor (42) and the difference exceeds a preset threshold, the controller (43) determines that the hollow elastic seal (23) has leaked.

Images