A quick connection device for cable branch joints and a method for designing the same

Abstract

The application relates to the technical field of power cable connection, and discloses a quick connecting device of a cable branch joint and a design method thereof. The device comprises an insulating shell, a conductive connecting assembly, a main line crimping assembly and a branch crimping assembly. The conductive connecting assembly comprises an upper layer conductor capable of being deformed under pressure and an integrated lower layer conductor. The lower layer conductor has a main line supporting part and a branch wiring part integrally extended from the main line supporting part. The main line crimping assembly makes the upper layer conductor and the main line supporting part jointly form an inclusive contact with an inclusive angle not less than 270 degrees in a cross section perpendicular to the trunk cable axis after the upper layer conductor is deformed under pressure. The branch crimping assembly independently compresses the branch cable to the branch wiring part to form a compression force path independent of the main line crimping assembly. The design method takes the minimization of the volume of the insulating shell as an optimization target, takes the contact resistance, temperature rise, effective heat dissipation area, electrical gap and creepage distance as constraint conditions, and performs coupling optimization on the structural parameters of the conductive connecting assembly, the crimping assembly and the insulating shell to determine the target structural parameters of the device.

Description

Technical Field

[0001] This application relates to the field of power cable connection technology, and in particular to a quick connection device and its design method for cable branch joints. Background Technology

[0002] In building electrical systems, industrial equipment, and power distribution networks, branch cables are typically drawn from the main trunk cable to connect electrical equipment or downstream power lines. Existing cable branch connection methods mainly include partially stripping the insulation layer of the main trunk cable and then wrapping it around the branch cable; cutting the main trunk cable and connecting it via terminals or copper busbars; and using T-connectors or branch clamps to complete the conductive connection between the main trunk cable and the branch cable. For applications requiring insulation protection, the connection point is usually located in a junction box, junction box, or insulating protective housing, and the conductor is clamped and fixed with screws or bolts.

[0003] However, manual winding connections are highly dependent on the operating process, and the effective contact area and contact pressure between conductors are not easy to maintain stably, which can easily lead to increased contact resistance and temperature rise at the connection point. Connecting after cutting the main cable will disrupt the continuity of the main cable and increase construction steps and connection interfaces. Although insulation piercing clamps can achieve branch connections without removing the insulation layer, the effective contact area between the piercing blade and the cable conductor is limited to the tip of the piercing tooth, resulting in a small contact area. During long-term operation, the piercing force is prone to attenuation due to stress relaxation of the insulation material, and there is a risk of local strand breakage for multi-strand fine strand conductors. Existing branch clamps mostly use U-shaped or V-shaped pressure plates with screws to locally compress the conductor. The contact angle between the pressure plate and the conductor is usually no more than 180°, making it difficult to form a circumferential enveloping contact. Moreover, the compression structure of the main line and the branch line often shares or is associated with the same set of bolts, and the installation, removal, or retightening of the branch cable may change the clamping state of the main cable. Meanwhile, the conductive structure, crimping structure and insulating shell in existing connection devices are usually designed separately, making it difficult to coordinate contact resistance, temperature rise, insulation distance and installation space. This results in a large device size, which is difficult to adapt to application environments with limited installation space, such as cable trenches, cable trays, shafts and building cable trays. Summary of the Invention

[0004] This application provides a quick-connection device and design method for cable branch joints. The main problem addressed by this application is that existing cable branch joints, under conditions of continuous branch connection of the main cable, struggle to simultaneously achieve sufficient conductive contact area and stable circumferential contact pressure through local crimping methods. Furthermore, the crimping operations of the main cable and branch cable are prone to mutual interference, and the addition of conductive and crimping components to improve crimping reliability can easily lead to an increase in device size. To address these issues, this application employs a collaborative design of the main cable insertion method, conductor contact interface, crimping force transmission path, and main branch conductive path. This design achieves a circumferentially enclosed conductive contact while maintaining the continuity of the main cable conductor, and integrates the main line conductive path with the branch conductive path, while ensuring that the main line crimping force path and the branch crimping force path are independent of each other.

[0005] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application provides a quick connection device for cable branch joints, including an insulating housing, a conductive connection assembly, a main line crimping assembly, and a branch crimping assembly; The insulating housing includes an insulating base and an insulating protective cover detachably connected to the insulating base. The insulating housing is provided with a main channel for the trunk cable to pass through and a branch channel for the branch cable to pass through. The upper side of the insulating base is provided with a cable placement opening communicating with the main channel. The conductive connection assembly is disposed within the insulating housing and includes an upper conductor and a lower conductor that are arranged opposite to each other and separable. The lower conductor is an integral conductor and includes a main line support portion and a branch connection portion integrally extended from the main line support portion. A main line clamping position is formed between the upper conductor and the main line support portion so that the main cable with partially stripped insulation layer and not cut can be laterally inserted into the main line clamping position through the cable placement opening. The upper conductor has a first arc-shaped contact surface facing the main line support portion, and the main line support portion has a second arc-shaped contact surface facing the upper conductor. At least one of the first arc-shaped contact surface and the second arc-shaped contact surface has an inner arc radius smaller than the outer circle radius of the exposed conductor of the main cable that is adapted to it when it is not compressed. The main line crimping assembly is used to apply a clamping force toward the main line support portion to the upper conductor, causing the upper conductor to undergo adaptive deformation, and to form an interference fit contact between the first arc-shaped contact surface and the second arc-shaped contact surface and the exposed conductor of the trunk cable, wherein the fit contact has an fit angle of not less than 270° in a cross section perpendicular to the axis of the trunk cable. The branch connection section is provided with a branch connection position for accommodating the exposed conductor of the branch cable, and the branch crimping assembly is used to crimp the exposed conductor of the branch cable to the branch connection section; The main line crimping assembly and the branch crimping assembly are set independently of each other, so that the main cable and the branch cable form independent crimping force paths respectively.

[0006] Optionally, at least one of the first arc-shaped contact surface and the second arc-shaped contact surface is provided with a plurality of micro-tooth structures spaced apart along the axial and / or circumferential direction of the trunk cable; When both the first arc-shaped contact surface and the second arc-shaped contact surface are provided with the micro-tooth structure, the micro-tooth structures of the two are staggered along the circumference of the trunk cable so that the upper conductor undergoes adaptive deformation and forms the enclosing contact. During this process, the micro-tooth structures located at different circumferential positions respectively form a pressing contact with the exposed conductor of the trunk cable. Preferably, the upper conductor has a first arc-shaped contact surface facing the main line support portion, and the main line support portion has a second arc-shaped contact surface facing the upper conductor. At least one of the first arc-shaped contact surface and the second arc-shaped contact surface has an inner arc radius smaller than the outer circle radius of the exposed conductor of the main line cable in the unpressurized state within a cross section perpendicular to the axis of the main cable, so that an interference fit is formed when the main line crimping assembly presses the upper conductor. Preferably, at least one of the first arc-shaped contact surface and the second arc-shaped contact surface is provided with micro-tooth structures distributed along the axial and / or circumferential direction of the trunk cable. The micro-tooth structures are used to break the oxide film on the exposed conductor surface of the trunk cable and increase the effective conductive contact points during the compression process.

[0007] Optionally, the branch connection portion is integrally extended from the side of the main line support portion, and the branch connection portion is provided with a branch connection hole for inserting the branch cable. The axis of the branch connection hole intersects with the axis of the main line channel so that the main cable and the branch cable form a T-shaped connection. Preferably, the main line crimping assembly includes at least two main line crimping bolts spaced apart along the axial direction of the trunk cable, and the at least two main line crimping bolts respectively apply a clamping force to the upper conductor so that the upper conductor deforms uniformly toward the main line support along its axial direction; The thread helix angle of the main line crimping bolt is less than the equivalent friction angle of the corresponding thread pair, so that the main line crimping bolt forms a thread self-locking under the crimped state.

[0008] Optionally, the insulating housing includes an insulating base and an insulating protective cover covering the insulating base. At least a portion of the insulating protective cover is made of transparent insulating material, or the insulating protective cover is provided with a transparent observation window for observing the insertion position and crimping status of the main cable and the branch cable.

[0009] Preferably, the cable inlet and outlet of the main channel and the branch channel are respectively provided with multi-layer concentric sealing rings or peelable sealing rings and sealing caps for axial compression of the sealing rings. The mating surface of the insulating base and the insulating protective cover is provided with a labyrinth waterproof groove, and the labyrinth waterproof groove is provided with an elastic sealing strip.

[0010] Optionally, the bottom of the insulating housing is provided with two mounting holes for fixing the quick connection device to the mounting base, and the two mounting holes are spaced apart along the diagonal direction of the bottom of the insulating housing; Preferably, the insulating housing is a flat rectangular housing, and the main cable channel and the branch cable channel are both located on the side of the insulating housing so that the main cable and the branch cable are introduced along the side of the insulating housing, and the overall height of the insulating housing is less than 50mm.

[0011] This application does not improve the conductivity of cable branch joints by simply increasing conductor size or bolt tightening force. Instead, it involves a coordinated design of the insertion method of the main cable, the initial curvature of the conductive contact interface, the stress deformation mode of the upper conductor, and the stress path of the main line and branch lines. The upper and lower conductors adopt a separable structure, allowing the uncut main cable to be inserted into the main line clamping position from the side of the insertion opening. The initial inner radius of at least one arc-shaped contact surface is smaller than the outer radius of the exposed conductor of the main cable, creating a mismatched curvature relationship before clamping. After the main line crimping assembly applies force, the upper conductor undergoes adaptive deformation, causing the initial local contact to gradually expand circumferentially towards the main cable conductor and form an interference fit contact with an containment angle of not less than 270°.

[0012] Based on this, the micro-tooth structure on the contact surface acts on different circumferential positions of the exposed conductor of the main cable as the contact area expands, breaking the oxide film on the conductor surface and forming multiple effective conductive contact points. Simultaneously, the main line support and branch connection sections are integrally formed from the same underlying conductor, eliminating the need for an additional conductive transition interface for the current transmitted from the main cable to the branch cable; the main line crimping assembly and the branch crimping assembly each form independent crimping force paths. Therefore, this application achieves a structural relationship of integrated conductive paths and decoupled mechanical crimping paths, reducing conductive transition interfaces while preventing the installation, disassembly, or retightening of branch cables from altering the already formed contact state of the main cable.

[0013] Furthermore, it also includes an intelligent sensing unit, which includes an openable installation structure, an energy harvesting unit, a current sampling unit, a temperature sampling unit, a processing unit, and a wireless communication unit. The opening and closing installation structure can be opened and surrounded around the main cable and then closed, so that the intelligent sensing unit can be installed on the main cable without cutting off the main cable. The energy harvesting unit is used to sense the power frequency magnetic field around the main cable and obtain induced electrical energy to power the intelligent sensing unit. The current sampling unit is used to collect the main circuit current of the main cable, and the temperature sampling unit is used to collect the temperature of the conductive voltage connection area corresponding to the clamping position of the main line. The processing unit is connected to the current sampling unit, the temperature sampling unit, and the wireless communication unit respectively, and is used to acquire the main circuit current and the temperature of the conductive voltage connection area, and to send the main circuit current and the temperature of the conductive voltage connection area to an external acquisition device through the wireless communication unit.

[0014] Optionally, the energy harvesting unit includes a mutual inductance energy harvesting structure, a rectifier circuit, and a voltage regulator circuit. The mutual inductance energy harvesting structure is disposed on the outer periphery of the main cable and is used to sense the power frequency magnetic field around the main cable. The rectifier circuit and the voltage regulator circuit are used to rectify and regulate the induced electrical energy generated by the mutual inductance energy harvesting structure. The temperature sampling unit includes a temperature probe and an elastic clamping member. The elastic clamping member is used to apply an elastic force to the temperature probe toward the conductive connection assembly, so that the temperature probe is continuously pressed against the conductive part corresponding to the clamping position of the main line, so as to directly collect the temperature of the conductive connection area.

[0015] Optionally, the wireless communication unit is a LoRa wireless communication unit, and the wireless communication unit is connected to an antenna for transmitting and / or receiving wireless signals; The processing unit is used to compare the main circuit current with a preset overcurrent threshold and compare the temperature of the conductive voltage connection area with a preset overtemperature threshold. When the main circuit current exceeds the preset overcurrent threshold and / or the temperature of the conductive voltage connection area exceeds the preset overtemperature threshold, the processing unit sends corresponding alarm information to the external acquisition device through the wireless communication unit and the antenna. The intelligent sensing unit also includes a status indicator connected to the processing unit, the status indicator being used to indicate the working status of the intelligent sensing unit.

[0016] In the above embodiments, the intelligent sensing unit is not used as an external monitoring device independent of the quick-connect device, but rather in conjunction with the continuous branch connection structure of the main cable. On one hand, the openable installation structure is compatible with the continuous lateral access method of the main cable, allowing both the connection device and the intelligent sensing unit to be installed without cutting the main cable. On the other hand, the temperature probe of the temperature sampling unit is directly positioned corresponding to the conductive contact area at the clamping location of the main cable, used to detect the actual operating temperature rise generated by the enclosed contact interface, thus aligning the temperature monitoring object with the critical conductive contact position in the quick-connect device. Therefore, while achieving continuous quick branch connection of the main cable, it is possible to acquire the main circuit current and the temperature of the crimped area, which affect connection reliability, online.

[0017] Secondly, this application provides a design method for a quick-connect device for cable branch joints, including: Obtain the structural parameters, electrical operating parameters, and installation space parameters of the main and branch cables to be connected, and determine the target contact resistance between the conductive connection components and the main cable based on the rated current and allowable contact voltage drop; Using the outer radius of the exposed conductor of the main cable as a reference, the uncompressed inner arc radius of the arc-shaped contact surface of at least one of the upper and lower conductors is set to be smaller than the outer radius of the exposed conductor to form an initial radial interference. The circumferential contact pressure distribution under the compression state is determined according to the initial radial interference, the axial length of the contact surface and the target containment angle, wherein the target containment angle is not less than 270°. The effective conductive contact area and the number of effective contact points are determined based on the circumferential contact pressure distribution, and the normal clamping force required to form the enclosing contact is determined in reverse based on the effective conductive contact area, the number of effective contact points, and the target contact resistance. The bolt preload and rated applied torque of the main line crimping assembly are determined based on the normal clamping force, and the thread helix angle of the crimping bolt in the main line crimping assembly is made smaller than the equivalent friction angle of the corresponding thread pair. The lower conductor is designed as an integral conductor including a main line support and a branch connection, and a main line crimping assembly and a branch crimping assembly corresponding to the main line support and the branch connection are respectively provided, so that the main line current and the branch current are transmitted through the integral conductor, and the main cable and the branch cable form independent crimping force paths. With minimizing the volume of the insulating shell as the optimization objective, and with contact resistance, allowable temperature rise, effective heat dissipation area, electrical clearance, and creepage distance as constraints, the structural parameters of the conductive connection assembly, the main line crimping assembly, the branch crimping assembly, and the insulating shell are iteratively adjusted to obtain the target structural parameters.

[0018] Preferably, determining the curvature of the contact surface between the upper conductor and the lower conductor includes: The inner arc radius of the contact surface of at least one of the upper conductor and the lower conductor in the uncompressed state is set to be smaller than the outer circle radius of the exposed conductor of the trunk cable to form an initial radial interference. The circumferential pressure distribution of the contact surface is determined based on the initial radial interference, the elastic modulus of the conductor material, and the containment angle. By adjusting the inner radius of the contact surface, the axial contact length, and the containment angle, the circumferential pressure distribution can meet the requirements of the target contact resistance.

[0019] Preferably, establishing the correlation between the contact resistance and the normal clamping force includes: Based on the material resistivity, material hardness, effective conductive contact area, normal clamping force, and number of effective contact points of the exposed conductor of the main cable and the conductive connection component, determine the shrinkage resistance and film resistance between the exposed conductor of the main cable and the conductive connection component. The contact resistance is determined based on the shrinkage resistance and the membrane resistance; The required normal clamping force is determined in reverse based on the target contact resistance, and the number of effective contact points is increased by setting micro-tooth structures on the contact surfaces of the upper conductor and / or the lower conductor.

[0020] Preferably, determining the structural parameters and rated applied torque of the main wire crimping assembly includes: Based on the thread pitch diameter, thread helix angle, thread pair friction coefficient, bearing surface friction coefficient, and bearing surface equivalent friction radius of the crimp bolt, establish the transmission relationship between the rated applied torque and the bolt preload. The bolt preload and the rated applied torque are determined based on the normal clamping force. The thread helix angle of the crimping bolt is set to be less than the equivalent friction angle of the corresponding thread pair, so that the crimping bolt forms a self-locking thread under the crimped state.

[0021] Preferably, the structural parameters of the insulating shell are coupled and optimized, including: The heat generation power of the conductive connection assembly is determined based on the rated current and the contact resistance. The minimum heat dissipation area required for the insulating shell is determined based on the effective heat dissipation area of ​​the insulating shell, the natural convection heat transfer coefficient, and the allowable temperature rise. The minimum electrical clearance inside the insulating housing is determined based on the rated voltage, air breakdown field strength, and safety factor, and the minimum creepage distance of the insulating housing is determined based on the preset insulation standard. The external dimensions of the insulating housing are reduced while meeting the requirements of minimum heat dissipation area, minimum electrical clearance, and minimum creepage distance.

[0022] Preferred options also include: The wire diameter, sealing groove depth, and sealing compression ratio of the sealing ring at the cable inlet and outlet are determined according to the target protection level of the quick-connect device. The contact pressure at the sealing interface is determined based on the sealing compression ratio, and the contact pressure is made greater than the external water pressure corresponding to the target protection level. The required locking force for the insulating protective cover is determined based on the sealing circumference, sealing contact width, and contact pressure, and the number, arrangement, and rated locking torque of the protective cover screws are determined based on the locking force.

[0023] Furthermore, this application provides a compact structural design method for a quick-connect device for cable branch joints, comprising the following steps: A. A curvature design model based on minimizing contact resistance for "enclosed engagement". Specific steps include: A1: In cable branch joints, the clamps engage with the conductors in a wraparound, interlocking manner. To quantify this characteristic, a non-matching curvature contact model is established. Let the cable conductor radius be... R c The inner radius of the conductive clamp is R clamp To achieve the "engulfing" effect during crimping, a design that satisfies R... clamp < R c This forms an initial interference contact.

[0024] A2: Contact resistance at the contact interface R contact Due to the shrinkage resistance R s and membrane resistance R f Composition. Introducing the modified Holm contact model:

[0025] in: ρ 1, ρ 2: Resistivity of the conductor and clamp materials, respectively; H Brinell hardness of the material; F N Normal contact pressure; n The number of effective contact spots is increased by the micro-tooth structure on the inner surface. n value; S eff Effective conductive area.

[0026] A3: To meet the requirements of engineering applications, the contact voltage drop must meet the following constraints:

[0027] in It is an inclusive angle θ The function. By optimizing the geometry of the clamp, the containment angle after force is increased. The distribution function of contact pressure at this time The integral value is the largest along the circumference.

[0028] B. Construct the thermo-mechanical co-optimization function for the compact shell, including the following steps: B1: To achieve structural compactness, an optimization function is established with the goal of maximizing space utilization:

[0029] B2: Subject to the following thermodynamic constraints: Temperature rise constraint (based on Joule's law and Newton's law of cooling):

[0030] in h conv The natural convection heat transfer coefficient is... A surf For the effective heat dissipation area of ​​the casing, This is the radiation heat dissipation efficiency factor. This formula is used to determine the minimum surface area required for the casing at a given current, and thus, to deduce the minimum volume.

[0031] Insulation creepage distance constraints: According to U rated =1000V, internal electrical clearance of the casing d gap Must meet:

[0032] in E air The air breakdown field strength K safe This is a safety factor (specifically, a value of 1.5 to 2.0).

[0033] C. Construct a bolt torque transmission and self-locking model, including the following steps: To address the characteristics of "high-strength bolt crimping, anti-loosening and vibration-resistant," a torque-preload transmission model for the threaded pair is established. To prevent vibration-induced loosening, the thread helix angle during design must be less than the equivalent friction angle. ρ v Apply torque T input Converted into axial clamping force F bolt The formula is:

[0034] in: d 2: Thread pitch diameter; : Coefficient of friction of the nut support surface; : Equivalent friction radius of the support surface. This is achieved by optimizing the radius of the support surface. r b and the selection of a specific coefficient of friction The material allows for [performance] at rated torque. F bolt It can provide sufficient contact pressure to cause the conductor to undergo plastic deformation and achieve a "biting" state.

[0035] D. Constructing a "two-layer distribution" spatial topology: To achieve continuous "T"-shaped connections of the main trunk lines and compress volume, this application adopts a vertically layered topology design. Specific steps include: D1: Design the trunk line channel. The bottom of the device is equipped with an open or semi-open trunk line channel. Through the upper and lower split logic, it is possible to directly "ride" or wrap the conductor on the main trunk line without cutting off the insulation layer.

[0036] D2: Design the branch overlay logic. The branch wire connection point is located above or to the side of the main trunk line, forming a double-layer wiring structure. The lower layer locks the main trunk line, and the upper layer connects one or more branch lines through combinations of wire clamps of different shapes, thereby achieving electrical shunting while minimizing the projected area.

[0037] E. Design a multi-mode adaptive installation interface. To adapt to working conditions in confined spaces (such as cable trenches, cable trays, and shafts), two installation interfaces are designed on the exterior of the housing, and a visual pre-tightening and safety protection system is constructed. Specific steps include: E1: Designed with a free-hanging interface. Utilizing the device's compact and lightweight design, it supports direct hanging from the cable without the need for additional mounting brackets, greatly reducing installation space requirements.

[0038] E2: Designed with diagonal fixing interfaces. The base of the housing has diagonally distributed mounting holes, which can be firmly installed on the base plate or wall with only two fixing points, further reducing the size of the base compared to the traditional four-corner fixing method.

[0039] E3: Transparent and Visual Design: The top of the device is equipped with a transparent insulating cover (or observation window) to visually inspect the insertion depth and crimping status of the internal wires without disassembling the outer casing, ensuring construction quality.

[0040] E4: Cable Tray Adaptor Structure (for Economy Models): Designed for building cable tray wiring, featuring a flat rectangular housing that can be fully accommodated within a standard cable tray, enabling concealed installation.

[0041] F. Innovative Family-Based Structural Design Based on Application Scenarios. This design methodology not only includes a general core conductivity model but also evolves into four specific structural implementation forms based on different environmental conditions to meet the full scenario coverage from indoor cable trays to underwater environments. Specific steps include: F1: Open high heat dissipation structure (corresponding to the basic model): Designed for the interior of industrial equipment or enclosed cabinets with extremely high heat dissipation requirements, it features an open architecture based on maximizing air convection.

[0042] Exposed frame design: The insulating base only supports the bottom and sides of the conductor, while the top retains a large heat dissipation channel to directly remove the heat from the junction through natural air convection.

[0043] Double-layer staggered wiring: It adopts a three-dimensional wiring logic of upper and lower layers and front and back staggered wiring. The lower layer main line and the upper layer branch line are stacked in a "well" shape or parallel in space to maximize the use of vertical space and keep the projected area of ​​the device when carrying large current (such as 150A-800A).

[0044] F2: Visualized Compact Protective Structure (Corresponding Protective Type): Designed for narrow cable trenches, cable trays, and shafts where insulation safety is required, featuring a fully enclosed compact protective structure.

[0045] Transparent and Visual Cover: The top of the housing integrates a high-transmittance polycarbonate (PC) cover, which, together with the foolproof design of the internal structure, allows maintenance personnel to visually inspect the insertion depth and crimping status of wires without removing the protective cover.

[0046] Suspended bracket-free system: Utilizing the high strength and lightweight design of the housing itself, the traditional external fixed bracket is eliminated. The "self-suspended" installation is achieved by the clamping force of the conductive wire clamp on the cable, which greatly reduces the dependence on the mounting back plate and adapts to irregular spaces.

[0047] F3: Multi-stage compression sealing structure (corresponding sealing type): Designed for outdoor, tunnel, and even short-term immersion environments, it features a sealing architecture based on the compression deformation of flexible media.

[0048] Adaptive wire diameter sealing technology: Multiple concentric or peelable sealing rings are set at the cable inlet and outlet. The matching layer is selected according to the actual outer diameter of the cable. By tightening the cap, axial pressure is generated, which forces the sealing ring to expand radially and fill the tiny gaps between the shell and the cable, achieving dynamic protection of IP54 to IP68.

[0049] Integrated labyrinth waterproof design: The joint surface of the upper and lower shells is designed with a labyrinth waterproof groove, which, together with a silicone sealing strip, prevents water penetration caused by capillary action.

[0050] F4: Flattened Cable Tray Integrated Structure (Economy Type): Designed for height-limited flattened architecture for cable trays and conduits in building electrical systems.

[0051] Low profile: Compress the height of the conductor and flatten the overall structure so that its total height can be fully accommodated inside a standard PVC or metal cable tray (such as a cable tray with a depth of <50mm).

[0052] Lateral integrated installation: This method changes the traditional top-entry cable method and optimizes it to lateral or oblique entry and exit, following the parallel direction of the cable in the cable tray, reducing the cable bending radius, and achieving integrated concealed installation with the building decoration.

[0053] Compared with the prior art, this application has at least the following beneficial effects: This application achieves branch connections in the main cable while maintaining conductor continuity through the synergistic cooperation of a continuous lateral insertion structure, a mismatched curvature containment contact structure, an integrated main branch conductive structure, and independent main branch clamping structures. Specifically, the mismatched curvature and adaptive deformation of the upper conductor transform the clamping force into a containment contact pressure distributed circumferentially along the main cable. The micro-tooth structure further forms multiple membrane-breaking conductive contact points within this containment area. The integrated lower conductor reduces the conductive transition interface between the main line and the branch line, while the independent clamping force paths for the main line and branch prevent the branching operation from altering the already established stable contact state of the main line. Therefore, this application ensures that the expansion of conductive contact area, reduction of contact resistance, maintenance of long-term clamping stability, and achievement of continuous and rapid branching of the main cable are not achieved by separate independent structures, but rather by the combined effect of the aforementioned structural relationships.

[0054] This application utilizes a mainline crimping assembly to deform the upper conductor under pressure, forming an enclosing contact with the lower conductor's mainline support portion within a cross-section perpendicular to the trunk cable axis, with an enclosing angle of not less than 270°. This structure transforms the concentrated pressure applied by the bolts into contact pressure distributed circumferentially along the trunk cable conductor, effectively expanding the conductive contact area and reducing the risk of localized stress concentration and localized damage to multiple conductors. The micro-tooth structure on the contact surface breaks down the oxide film on the conductor surface and increases the number of effective contact points, further reducing contact resistance. The measured contact voltage drop can be controlled within 1.98mV, and it can pass a 120A / mm² short-circuit current impact test, which helps reduce the operating temperature rise at the connection point and improves electrical stability.

[0055] This application integrates the main line support and branch connection section into a single lower conductor. Current in the main cable can be directly transmitted to the branch connection section via this lower conductor, eliminating the need for a separate conductive transition component. This structure reduces the number of conductive connection components and the conductive transition interface, while shortening the conductive path between the main line connection area and the branch connection area. This helps reduce additional contact resistance caused by interface oxidation, loose connections, or insufficient contact area, and also reduces the space occupied by the conductive connection components.

[0056] This application utilizes independent mainline crimping and branch crimping assemblies to create independent crimping force paths for the main cable and branch cables. When installing, disassembling, or retightening branch cables, there is no need to release or adjust the crimping state of the main cable, which helps maintain the long-term stability of the mainline contact resistance and improves the convenience of branch connection operations and subsequent maintenance. Simultaneously, the thread helix angle of both the mainline crimping bolt and the branch crimping bolt is smaller than the equivalent friction angle of the corresponding thread pair, forming a self-locking thread under crimping conditions, which reduces the attenuation of crimping force caused by cable vibration, thermal cycling, or short-term electrodynamic forces.

[0057] The circumferentially staggered arrangement means that the multiple micro-teeth do not act on the same radial position of the conductor, but rather form multiple film-breaking contact positions in different regions of the outer periphery of the conductor as the containment contact range expands.

[0058] This application aims to minimize the volume of the insulating housing. Contact resistance, clamping force, temperature rise, effective heat dissipation area, electrical clearance, and creepage distance are used as structural design constraints. Electro-thermal-mechanical multi-physics coupling optimization is applied to the conductive connection components, crimping components, and insulating housing to reduce the overall size of the device while meeting conductivity, heat dissipation, and insulation safety requirements. The overall height of the insulating housing can be controlled within 50mm, which is beneficial for applications with limited installation space, such as cable trenches, cable trays, shafts, and building cable trays.

[0059] This application utilizes a multi-level sealing structure consisting of a peelable multi-layer concentric sealing ring, an axial compression gland, a labyrinthine waterproof groove on the shell mating surface, and an elastic sealing strip. This allows for flexible matching of the sealing level according to the actual outer diameter of the cable, achieving IP54 to IP68 protection levels and reducing the risk of moisture and dust intrusion into the conductive contact area, which could lead to corrosion or a decrease in insulation performance.

[0060] This application also allows for the installation of a snap-fit ​​intelligent sensing unit within the quick-connect device, enabling the sensing unit to be installed without cutting the main cable. It obtains the induced electrical energy required for operation through the power frequency magnetic field surrounding the main cable, thereby reducing additional power supply wiring. A current sampling unit acquires the main circuit current, while a temperature sampling unit directly detects the temperature of the conductor crimping area corresponding to the main cable clamping position via an elastic clamping structure, ensuring that the monitored object corresponds to the actual crimping position affecting the conductivity reliability of the branch joint. By integrating quick-connect branching with current and crimping area temperature sensing into the same application system, it is possible to acquire connection device operating status data while achieving continuous quick branching of the main cable, and to report information in case of over-temperature or over-current conditions. Attached Figure Description

[0061] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this application in any way. Furthermore, the shapes and scales of the components in the drawings are merely illustrative to aid in understanding this application and do not specifically limit the shapes and scales of the components. In the drawings: Figure 1 This is an exploded view of the overall structure of a compact quick-connect device for cable branch joints implemented according to this application; Figure 2 This is a schematic diagram of a compact conductive clamp "enclosing engagement" structure of a quick connection device for cable branch joints implemented according to this application; Figure 3 This is a schematic diagram of the intelligent sensing unit structure provided in an embodiment of this application; Figure 4 This is a schematic diagram showing the state of the intelligent sensing unit provided in this application when it is installed on the main cable.

[0062] Specific implementation To make the objectives and technical solutions of this application clearer and easier to understand, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0063] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0064] This application provides a quick connection device and design method for cable branch joints, aiming to solve the problems of limited effective contact area of ​​conductors, mutual influence between the main line and branch line compression states, and large structural space occupation in existing cable branch joints. The device includes an insulating shell, a conductive connection assembly, a main line crimping assembly, and a branch crimping assembly. The conductive connection assembly includes a compressible upper conductor and an integral lower conductor. The lower conductor has a main line support portion and a branch connection portion integrally extended from the main line support portion. After the main line crimping assembly compresses the upper conductor, the upper conductor and the main line support portion together form an enclosing contact with an enclosing angle of not less than 270° in a cross-section perpendicular to the axis of the main cable. The branch crimping assembly independently crimps the branch cable to the branch connection portion, forming an independent compression force path with the main line crimping assembly. This design method optimizes the device by minimizing the volume of the insulating shell, using contact resistance, temperature rise, effective heat dissipation area, electrical clearance, and creepage distance as constraints. It couples and optimizes the structural parameters of the conductive connection assembly, crimping assembly, and insulating shell to determine the target structural parameters of the device.

[0065] This method aims to optimize the internal conductive structure, crimping mechanism, and insulating shell of the connection device through mathematical modeling. While achieving rapid branching without cutting off the main line, it maximizes the contact area through a unique "enclosing interlocking" contact surface design and optimizes the crimping torque using a mechanical transmission model of high-strength bolts. Thus, while meeting the requirements of structural mechanical strength, achieving a UL94 V-0 flame retardant rating for the insulation material, and ensuring that the contact voltage drop does not exceed 1.98 mV, the device size is reduced, and it is adaptable to application requirements with different protection levels such as IP20, IP54, or IP68.

[0066] The technical content of this application will be further described below with reference to the accompanying drawings. It should be understood that the following embodiments are used to illustrate this application and are not intended to limit the scope of protection of this application. Unless otherwise specified, the various embodiments and their technical features can be combined with each other.

[0067] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides a quick connection device for cable branch joints, including an insulating housing, a conductive connection assembly, a main line crimping assembly, and a branch crimping assembly. The insulating housing is disposed outside the conductive assembly and is used to accommodate the conductive assembly and the connection parts of the main cable and branch cable, and to isolate the live connection parts from the external environment.

[0068] The conductive component includes an upper conductor and a lower conductor that cooperate with each other. A main line connection area is formed between the upper and lower conductors for the main cable conductor to be installed. The main line connection area extends along the axial direction of the main cable, so that the main cable can form an electrical connection with the conductive component without being cut off.

[0069] The lower conductor includes a main line support and a branch connection, which are integrally formed. The main line support supports the main cable conductor from below, while the branch connection forms an electrical connection with the branch cable conductor. The main line support and the branch connection are formed from the same conductive structure, and there is no connection interface between them that requires a separate conductive transition to achieve current transmission.

[0070] By integrating the main line support and branch connection into one piece, the current in the main cable can be directly transmitted to the branch connection through the lower conductor. This reduces the conductive transition interface between the main line connection area and the branch connection area, shortens the current transmission path, and reduces additional contact resistance caused by interface oxidation, loose connections, or insufficient contact area. Simultaneously, the lower conductor can simultaneously serve as the main cable support, main line conductor, and branch conductor, which helps reduce the number of parts and space occupied by the conductive components.

[0071] The upper conductor is positioned above the main cable conductor and can deform towards the main cable conductor under the clamping action applied by the main line crimping device. This deformation includes at least elastic deformation that adapts the inner contact profile of the upper conductor to the outer circumferential profile of the main cable conductor. This adaptive deformation of the upper conductor reduces localized gaps caused by errors in the main cable diameter, conductor roundness, or uneven surfaces of multiple conductors, resulting in a more continuous contact between the upper conductor and the main cable conductor.

[0072] The upper and lower conductors together form an enclosing contact structure around the main cable conductor, with an enclosing angle of not less than 270°. The enclosing angle refers to the effective encirclement angle of the main cable conductor by the upper and lower conductors acting together within a cross-section perpendicular to the axial direction of the main cable.

[0073] The containment angle is not less than 270°, ensuring that most of the circumference of the main cable conductor is surrounded and compressed by the conductive components. Compared to crimping structures that only form point contacts or narrow line contacts on opposite sides, this containment contact structure can expand the effective conductive contact area, dispersing the main line clamping force along the circumference of the main cable conductor, reducing the possibility of local stress concentration and localized damage to multiple conductors.

[0074] The main line crimping component is used to apply main line clamping force to the upper conductor, causing the upper conductor to move or deform towards the lower conductor, and clamping the main cable conductor between the upper and lower conductors. The main line clamping force is distributed through the upper conductor to the outer periphery of the main cable conductor, and further transmitted to the main line support part of the lower conductor, thereby forming the main line clamping force path.

[0075] A branch crimping fitting is provided corresponding to the branch connection portion to maintain a tight contact between the branch cable conductor and the branch connection portion. The force applied by the branch crimping fitting is transmitted to the branch connection portion through the branch cable conductor, thereby forming a branch crimping force path.

[0076] The main line clamping force path and the branch clamping force path are independent of each other. Adjusting the main line clamping force will not directly change the clamping state of the branch cable, and adjusting the branch clamping force will not directly release the clamping force of the main cable. Therefore, when installing, disassembling, or adjusting branch cables, the crimped state of the main cable can be maintained, reducing the possibility that the main line contact resistance will change due to branching operations.

[0077] In use, the conductor section to be connected in the main cable is placed between the upper and lower conductors, and the main cable crimping device applies pressure to the upper conductor. The upper conductor then adapts to the outer circumference of the main cable conductor, forming an enclosing contact of at least 270° with the lower conductor. The branch cable conductor is placed in the branch connection section and is crimped separately by the branch crimping device. The current in the main cable enters the integrated branch connection section through the upper and lower conductors, and is then transmitted to the branch cable.

[0078] With the above structure, the main cable can be branched without being cut; the enclosed contact structure can expand the effective conductive contact area and improve the uniformity of contact pressure distribution; the integrated lower conductor can shorten the current transmission path between the main line connection area and the branch connection area; the independent force paths can avoid interference between the main line clamping operation and the branch clamping operation, thus taking into account connection reliability, installation convenience and structural compactness.

[0079] Furthermore, in this embodiment, a continuous synergistic process is formed between the various structures. When the main cable is not cut, the upper and lower conductors are initially separated, allowing the exposed conductor of the main cable, after partial stripping of the insulation layer, to laterally enter the main cable clamping position through the wire placement opening of the insulation base. Since the initial inner radius of at least one of the first and second arc-shaped contact surfaces is smaller than the outer radius of the exposed conductor of the main cable, a mismatched curvature contact with an initial interference tendency is initially formed between the conductive component and the main cable before the main cable crimping assembly is fully clamped.

[0080] As the main line crimping assembly continues to apply clamping force, the upper conductor undergoes adaptive deformation towards the main line support. The actual contact range between the first and second arc-shaped contact surfaces and the exposed conductor of the main cable expands circumferentially from the initial contact area until an enclosing contact with an enclosing angle of not less than 270° is formed. Thus, the local axial load provided by the main line crimping assembly is transformed into contact pressure distributed along the outer periphery of the main cable via the upper conductor.

[0081] When the contact surface is equipped with a micro-tooth structure, multiple micro-tooths enter an effective stress state as the enclosing contact range expands. This causes the oxide film on the conductor surface at different circumferential positions of the main cable to be locally broken, forming multiple effective conductive contact points. Therefore, this embodiment does not rely on a single high-voltage point to obtain low contact resistance, but rather establishes a stable conductive interface through the combined effect of circumferential enclosing pressure and multi-point micro-tooth contact.

[0082] After the main line crimping is completed, the current in the trunk cable is directly transmitted to the branch connection section through the integrated lower conductor's main line support. When installing or removing branch cables, only the branch crimping assembly needs to be operated to change the crimping state between the branch cable and the branch connection section, while the main line crimping assembly does not need to be loosened, thus maintaining the existing trunk cable containment contact state. This forms a structural relationship of "integrated conductive path and independent main and branch crimping paths".

[0083] In the above embodiments, the quick-connect device mainly forms an enclosing contact with the main cable through the upper and lower conductors, and achieves conductive connection between the main cable and branch cables through an integrated lower conductor. Simultaneously, it maintains the stability of the main line connection state through independent main line crimping force paths and branch crimping force paths. Based on this, to further obtain the main circuit current and the temperature of the crimping area corresponding to the main line clamping position during actual operation of the quick-connect device, this application can further configure an intelligent sensing unit on the basis of the above quick-connect device. The intelligent sensing unit does not change the basic connection and force relationship between the upper conductor, lower conductor, main line crimping assembly, and branch crimping assembly, but is configured in conjunction with the quick-connect device to acquire operating parameters related to the conductive connection state. The specific structure will be further described in subsequent embodiments.

[0084] Example 2 See Figures 1 to 2 This embodiment provides a quick connection device suitable for scenarios such as building electrical, industrial power distribution, cable trays, cable trenches, internal wiring of equipment, and cable tray wiring, especially suitable for occasions where the main cable cannot be cut and the installation space is limited.

[0085] The quick-connect device includes an insulating protective cover 1, protective cover screws 2, main line crimping bolts 3, upper conductor 4, main cable 5, lower conductor 6, branch crimping bolts 7, branch cables 8, and an insulating base 9. The upper conductor 4 and lower conductor 6 constitute a conductive assembly. The main cable 5 passes through the main line connection direction of the conductive assembly, and the branch cable 8 is connected to the lower conductor 6 in the direction intersecting with the main cable 5.

[0086] The insulating protective cover 1 and the insulating base 9 are detachably connected and together form an accommodating space. The protective cover screw 2 is used to fix the insulating protective cover 1 to the insulating base 9. The insulating protective cover 1 and the insulating base 9 form main line passages on both sides of the main cable 5 and branch passages on the side where the branch cable 8 is located.

[0087] During installation, the insulating protective cover 1 and the upper conductor 4 can be removed first, and the conductor section of the main cable 5 with its insulation stripped can be directly placed into the lower conductor 6 without passing the end of the main cable 5 through the closed channel or cutting the main cable 5. After placement, the upper conductor 4 can be reinstalled and tightened. Thus, even if both ends of the main cable 5 are fixed, branch connections can still be made in the middle of the main cable 5.

[0088] The lower conductor 6 includes an integrally formed main line support and a branch connection. The main line support extends axially along the trunk cable 5, and the branch connection extends laterally from one side of the main line support. Together, the main line support and the branch connection form a T-shaped conductive structure. A branch cable connection position is formed within the branch connection position. After the branch cable 8 is inserted into the branch cable connection position, it is tightened by the branch crimping bolt 7.

[0089] There is no additional overlapping conductive interface between the main line support and the branch connection, which reduces the number of series conductive interfaces inside the joint, allowing the lower conductor 6 to simultaneously perform the functions of main line support, main line conduction and branch conduction.

[0090] The upper conductor 4 is configured as a groove-shaped crimping body extending axially along the trunk cable 5, with a concave arc-shaped contact surface on the side facing the trunk cable 5. The main line support portion of the lower conductor 6 has a concave arc-shaped contact surface opposite to the upper conductor 4. The upper and lower concave arc-shaped contact surfaces together form an enclosing contact area for surrounding the trunk cable conductor.

[0091] In this embodiment, the initial contact curvature of the upper conductor 4 and the lower conductor 6 is not exactly the same as the outer circumferential curvature of the main cable conductor. Optionally, the initial radius of curvature of the concave arc-shaped contact surface of at least one of the upper conductor 4 and the lower conductor 6 is smaller than the outer circumferential radius of the main cable conductor, thereby forming a radial initial interference between the clamping contact surface and the main cable conductor.

[0092] After the main line crimping bolt 3 applies clamping force, the upper conductor 4 undergoes adaptive deformation, causing the actual contact range between the upper conductor 4, the lower conductor 6, and the main cable conductor to expand circumferentially. For example... Figure 2 As shown, the containment angle θ formed by the upper conductor 4 and the lower conductor 6 is not less than 270°. This containment angle ensures that most of the outer periphery of the main cable conductor is under pressure and conduction, and that the concentrated pressure generated by the main line crimping bolt 3 is converted into contact pressure distributed circumferentially along the main cable conductor via the upper conductor 4, thereby expanding the effective contact area and reducing the possibility of local pressure damage.

[0093] In some embodiments, the contact surfaces of the upper conductor 4 and the lower conductor 6 facing the main cable conductor are provided with multiple micro-tooth structures. The micro-tooth structures can be distributed at intervals along the axial and circumferential directions of the main cable 5, and the positions of the micro-tooths on the upper and lower contact surfaces can also be staggered to form an enclosing interlocking contact.

[0094] During the crimping process, the micro-tooth structure can break off part of the oxide film on the surface of the main cable conductor and increase the number of effective contact points, so that the multiple conductors can be rearranged appropriately and undergo local micro-plastic deformation, thereby forming a relatively stable airtight contact area and reducing the influence of the surface film on the contact resistance.

[0095] The main line crimping bolt 3 mates with the threaded connection on the upper conductor 4 to apply main line crimping force to the trunk cable 5. The branch crimping bolt 7 mates with the branch connection part of the lower conductor 6 to apply branch crimping force to the branch cable 8.

[0096] The main line crimping bolt 3 operates in the direction corresponding to the upper conductor 4 and the main line support, while the branch crimping bolt 7 operates in the direction corresponding to the branch cable 8 and the branch connection. The two form independent force paths. When installing or adjusting the branch cable 8, it is not necessary to loosen the main line crimping bolt 3, thus reducing the impact of branching operations on the crimping state of the main cable 5.

[0097] High-strength bolts can be used for both the main line crimping bolt 3 and the branch crimping bolt 7. The thread helix angle of the threaded pair is smaller than the equivalent friction angle, giving the threaded pair a self-locking capability after tightening. Therefore, even if the connection device is subjected to cable vibration, thermal cycling, or short-term electrodynamic forces, the threaded pair is not prone to rotating in the opposite direction on its own, thereby improving the ability to retain the tightening force.

[0098] In some embodiments, the insulating protective cover 1 is made of a transparent material, or a transparent observation window is provided on the insulating protective cover 1. Operators can observe the main line crimping position, branch cable insertion depth, crimping bolt status, and seal assembly status through the transparent area, and perform routine inspections without disassembling the entire insulating housing.

[0099] The insulating protective cover 1 and the insulating base 9 can be made of high-strength insulating materials that meet the UL94 V-0 flame retardant rating requirements, and can be made of materials that are resistant to aging, impact, and tracking, depending on the environment in which they are used. For general indoor protection scenarios, the insulating housing can provide IP20 level electric shock protection; for dusty, humid, or outdoor scenarios, IP54 to IP68 level protection can be achieved by setting a sealed structure.

[0100] In embodiments requiring a tight seal, the main line access port and branch access port each have one or more concentrically arranged seals. The concentric seals can be configured as peelable structures, allowing installers to remove the corresponding layers of sealing rings based on the outer diameter of the main cable 5 and branch cable 8, so that the through-hole size of the seal matches the outer diameter of the cable.

[0101] After the cable passes through the seal, the gland applies axial pressure to the seal, causing it to expand radially and press against the outer circumference of the cable. A labyrinthine mating edge and an elastic sealing strip can also be provided between the insulating protective cover 1 and the insulating base 9. The labyrinthine mating edge extends the path for moisture and dust to enter the housing, while the elastic sealing strip undergoes compression deformation when the insulating protective cover 1 and the insulating base 9 are tightened, thereby improving the sealing reliability at the housing joint.

[0102] The insulating base 9 can be provided with two diagonally arranged mounting holes. These two diagonally arranged mounting holes reduce the area occupied by the mounting interface while restricting the translation and rotation of the insulating base 9, making it suitable for fixing to cable trays, equipment panels, or the bottom of cable ducts. Depending on the actual installation conditions, the connection device can also utilize the clamping action of the main cable 5 and conductive components to form a suspended installation, without the need for a separate mounting bracket.

[0103] In the embodiment used for cable trays, the insulating housing adopts a flat rectangular structure, and the main cable 5 and branch cables 8 enter from the side or oblique side of the insulating housing. The total height of the insulating housing is less than 50mm, allowing the connecting device to be installed within the depth range of a standard PVC cable tray or metal cable tray. Lateral entry also reduces the space occupied by the cable due to vertical bending and reduces the bending stress of large-section cables.

[0104] Depending on the rated current, installation space, and protection level, the quick-connect device can be configured as an open heat dissipation structure, a visible protection structure, a multi-level sealed structure, or a flat cable tray structure.

[0105] The open-type heat dissipation structure employs a skeletal insulating support. The insulating base supports the bottom and sides of the conductive components, while retaining ventilation areas at the top or sides. The upper and lower conductive components can be staggered to form a "well" shape or arranged in parallel. This structure can be used for current ratings of approximately 150A to 800A, increasing the natural heat dissipation area while reducing the projected area.

[0106] The visual protection structure adopts a fully enclosed insulating shell and a transparent protective cover, and can be self-suspended by using the clamping action of conductive components on the main cable 5, so as to take into account the prevention of accidental contact, status observation and bracket-free installation.

[0107] The multi-stage sealing structure uses peelable concentric seals, glands, labyrinth mating edges, and elastic sealing strips to achieve IP54 to IP68 protection levels depending on the tightness of the seals and the housing.

[0108] The flat cable tray structure keeps the total height of the insulating shell within 50mm and uses lateral or oblique cable entry, allowing the main cable 5 and branch cables 8 to be arranged along the cable tray direction to adapt to indoor wiring scenarios with limited installation height.

[0109] This embodiment also provides a design method for the aforementioned quick-connect device. This design method treats electrical contact, mechanical clamping, thermal conduction, insulation spacing, sealing, and housing volume as interrelated design conditions, enabling the quick-connect device to reduce its overall size while meeting electrical, mechanical, and insulation performance requirements.

[0110] First, establish the input parameter vector Pin. The input parameter vector Pin can include at least the rated voltage Urate and the load current. I load Cable diameter range Allowable contact voltage drop ΔUlimit, conductor material parameters, housing material parameters, maximum allowable temperature, and target protection level.

[0111] In one embodiment, the rated voltage is: .

[0112] The allowable contact pressure drop must meet the following requirements: ΔU≤1.98mV.

[0113] Determine the upper limit of the target contact resistance based on the load current and allowable contact voltage drop: .

[0114] Among them, R th ΔU is the upper limit of the target contact resistance. limit To allow for contact voltage drop, I load Let be the load current. Based on the above relationship, the contact voltage drop requirement is converted into a contact resistance constraint that can be used for iterative design of the contact structure. As the load current increases, the upper limit of the target contact resistance decreases accordingly. Subsequently, the constraint can be met by increasing the effective contact area, increasing the number of effective contact points, or adjusting the clamping force.

[0115] Determine the radius R of the main cable conductor. cond and the initial radius R of the clamping contact surface clamp And the initial radius of the clamping contact surface should be slightly smaller than the radius of the main cable conductor, that is: R clamp <Rcond .

[0116] The initial radial interference between the clamping contact surface and the main cable conductor is: δ r =R cond -R clamp >0.

[0117] Where, δ r R is the initial radial interference. cond Main cable conductor radius, R clamp The initial radius of the arc of the clamping contact surface.

[0118] In some implementations, a non-Hertzian contact model can be used to describe the circumferential contact stress under initial interference: σ θ (φ)=E mat ·(δ r / R clamp )·cos(πφ / α wrap ).

[0119] Where, σ θ (φ) represents the contact stress at the circumferential position φ, E mat δ is the elastic modulus of the conductor or clamping material. r R is the initial radial interference. clamp Let α be the initial radius of the circular arc of the clamping contact surface. wrap For the inclusion angle.

[0120] The containment angle satisfies: α wrap ≥270°.

[0121] With an axial contact length of L axial The effective contact area can be estimated using the following formula: A eff =L axial ·∫[-α wrap / 2,+α wrap / 2]R cond ·η(σ θ )dφ.

[0122] Among them, A eff For effective contact area, L axial R is the contact length of the clamping structure along the axial direction of the main cable. cond Main cable conductor radius, η(σ) θ ) represents the surface roughness contact coefficient that varies with contact stress, and φ represents the angular variable corresponding to the circumferential position of the main cable conductor.

[0123] In some implementations, the contact resistance of the enclosing contact area can be calculated using the following formula: .

[0124] Among them, R c ρ1 and ρ2 are the resistivity of the main cable conductor and the clamping conductor, respectively, HB is the Brinell hardness, and F is the contact resistance. N ρ is the normal clamping force borne by the contact area. film A is the equivalent resistivity of the surface film. eff For effective contact area.

[0125] During the design process, the axial contact length Laxial and the initial radial interference δr are iterated to ensure that the calculated contact resistance satisfies the following: R c ≤R th .

[0126] When setting up a micro-tooth structure and considering the number of effective contact points, a modified Holm contact resistance relationship can also be used: .

[0127] Among them, R contact R is the total contact resistance. s For the shrinkage resistance, R f The film resistance is given by ρ1 and ρ2, which are the resistivities of the two contact conductors, respectively. H is the Brinell hardness parameter, n is the number of effective contact points, and F is the resistivity of the film. N S is the normal clamping force. eff For the effective conductive area, σ film The equivalent parameters of the surface film are given. The micro-tooth structure reduces shrinkage resistance and film resistance by breaking down the surface film and increasing the number of effective contact points n.

[0128] The contact voltage drop also satisfies: .

[0129] Among them, I rated For the rated current, F N (θ) represents the equivalent normal clamping force that varies with the containment angle θ. By ensuring that the containment angle θ is not less than 3π / 2 and by integrally evaluating the circumferential pressure distribution P(φ), the effective force perimeter and effective contact area can be increased within a finite axial length, thereby reducing the contact pressure drop.

[0130] The two contact resistance relationships described above can be used for calculations with different design accuracies and contact surface structures. The first relationship focuses on the effective contact area and the equivalent resistivity of the film layer, while the second relationship further considers the number of effective contact points formed by the micro-tooth structure. In practical design, the appropriate calculation relationship can be selected based on material test data and contact surface morphology, or the results of the two calculations can be cross-checked.

[0131] To ensure sufficient normal clamping force in the containment contact area, the minimum normal clamping force can be determined using the following formula: F N,min ≥σ yield ·A eff ·sin(α wrap / 2).

[0132] Among them, F N,min For the minimum normal clamping force, σ yield A represents the yield strength of the corresponding conductor material. eff For the effective contact area, α wrap For the inclusion angle.

[0133] When selecting materials and performing stress calculations, the clamping force should be sufficient to break the oxide film in the micro-tooth structure and form a stable contact, but should not cause excessive plastic deformation in the main cable conductor that would affect its current-carrying capacity. By dispersing the clamping force through an enclosing contact structure, local peak stresses can be reduced while maintaining the total normal clamping force.

[0134] The bolt preload and the input tightening torque can be calculated using the following formula: F bolt =T input / [d2·tan(λ+ρv)+μ b ·r b ].

[0135] Among them, F bolt T is the bolt preload. input The input tightening torque is given by d2, where d2 is the thread pitch diameter, λ is the thread helix angle, and ρ is the thread pitch angle. v For the equivalent friction angle, μ b Let r be the friction coefficient of the bearing surface. b The effective friction radius of the supporting surface is denoted as .

[0136] In implementations where further consideration needs to be given to thread profile and bearing surface friction, the following can be adopted: T apply =F bolt ·{(d2 / 2)·tan[ψ+arctan(μ th / cosβ)]+(D w / 2)·μw}

[0137] Among them, T apply For the tightening torque applied, F bolt d2 is the bolt preload, d2 is the thread pitch diameter, ψ is the thread helix angle, and μ is the thread pitch angle. th β is the thread friction coefficient, β is the thread flank angle, and D is the thread tooth friction coefficient. w μ is the equivalent diameter of the supporting surface. w The coefficient of friction of the supporting surface.

[0138] By selecting the thread specification, friction parameters, and rated tightening torque, the bolt preload can be made to meet the following requirements: F bolt >F N,min .

[0139] At the same time, the thread helix angle of the threaded pair should be less than the equivalent friction angle, and the anti-loosening friction torque should satisfy: T fric >T loose .

[0140] Among them, T fric T is the anti-loosening friction torque that the threaded pair and bearing surface can provide. loose This is to compensate for the loosening torque that may be generated by vibration, thermal cycling, or external loads. Therefore, it is possible to maintain a compressed state while achieving the target contact resistance, reducing contact resistance drift during long-term operation.

[0141] Based on the calculation results of the effective contact area and clamping force, the dimensions of the main line support and the branch connection of the lower conductor 6 are determined, and the main line support and the branch connection are integrally formed. The main line crimping bolt 3 and the upper conductor 4 form the main line clamping force path, and the branch crimping bolt 7 and the branch connection form the branch clamping force path.

[0142] During the design process, the required clamping force and tightening torque for the main line connection and branch connection are calculated separately to ensure that the main line crimping operation and the branch crimping operation are independent of each other. With this force topology, the crimped state of the main cable 5 can be maintained when adding, removing, or adjusting branch cables 8.

[0143] The compactness of the insulating housing can be evaluated using the effective volume utilization rate: .

[0144] Where η is the effective volume utilization rate, V effective V is the internal effective functional volume. total S represents the total volume. i Let l be the cross-sectional area of ​​the i-th internal functional component or channel. i V represents the corresponding effective length. housingThis refers to the volume of the shell.

[0145] The external dimensions of the insulating housing can be optimized by the following objectives: V min =min(L box ·W box ·H box ).

[0146] Wherein, Lbox, Wbox, and Hbox represent the length, width, and height of the insulating shell, respectively. During the optimization process, constraints related to electrical contact, temperature rise, insulation, and installation space were simultaneously met.

[0147] The thermal balance constraint of the joint can be expressed as: I²R c ≤h conv ·S surf ·(T max -T amb ).

[0148] Where I is the current through the connector, R c h is the contact resistance. conv S is the natural convection heat transfer coefficient. surf T is the effective heat dissipation surface area of ​​the casing. max To allow the highest temperature, T amb The ambient temperature.

[0149] When performing thermal design of the insulating shell, the following can also be adopted: .

[0150] Among them, T rise T is the calculated temperature of the connected region. amb R represents the ambient temperature. contact h is the contact resistance. conv A is the natural convection heat transfer coefficient. surf η is the effective surface area of ​​the shell. rad For radiation efficiency, T max The maximum permissible temperature.

[0151] By increasing the effective heat dissipation surface area, setting up ventilation areas, and reducing contact resistance, the temperature of the connection area can be controlled while reducing the volume of the insulating shell.

[0152] The air gap can be determined according to the following formula: d gap ≥(U rated / E air )·K safe .

[0153] Where, d gap For the required air gap, Urated For the rated voltage, E air K is the air breakdown field strength. safe For the safety factor, K safe You can choose 1.5 to 2.0.

[0154] The thickness of the insulation material can be checked according to the following formula: t ins ≥(U rate / E breakdown )·k safe .

[0155] Among them, t ins U is the minimum thickness of the insulating material. rate For the rated voltage, E breakdown k is the breakdown field strength of the insulating material. safe This is the insulation safety factor.

[0156] At rated voltage U rate In the implementation with a voltage of 1000V, the creepage distance satisfies: L creepage ≥12.5mm.

[0157] The aforementioned air gaps, insulation thickness, and creepage distances can be verified in accordance with the relevant requirements of IEC 60947-7-1. By simultaneously optimizing the double-layer spatial topology of the conductive components, the location of branch connections, and the wall thickness of the insulating housing, the external projected dimensions of the housing can be reduced while meeting the requirements for electrical clearance and insulation reliability.

[0158] For connection devices that require IP68 protection, the level of the peelable concentric seal, the cross-sectional size of the seal, and the preload of the gland can be determined based on the outer diameter of the main cable 5 and the branch cable 8.

[0159] The compression ratio of the seal can be determined by the following formula: ε=(d0-h) / d0.

[0160] Where ε is the seal compression ratio, d0 is the cross-sectional diameter of the seal in its uncompressed state, and h is the depth of the sealing groove.

[0161] The peak pressure at the sealing contact can be estimated using the following formula: P peak =E rubber ·(1.25ε 1.5＋50ε 6).

[0162] Among them, P peak For the peak pressure of the sealing contact, E rubber This is the elastic modulus of the rubber material.

[0163] For IP68 operating conditions with a water pressure not lower than 0.02 MPa, the peak pressure at the sealing contact must meet the following requirements: P peak >P water,pressure ·S factor .

[0164] Among them, P water,pressure For external water pressure, S factor This is the sealing safety factor.

[0165] The total clamping force provided by the fasteners of the insulating protective cover 1 meets the following requirements: F cover =n screw ·F screw,preload ≥∫(L seal )P peak ·w contact ·dl.

[0166] Among them, F cover n is the total clamping force of the insulating protective cover 1. screw For the number of protective cover screws 2, F screw,preload For the preload of a single protective cover screw 2, L seal w is the perimeter of the seal. contact is the sealing contact width, and l is the positional variable along the circumference of the seal.

[0167] By calculating the sealing parameters mentioned above, the seal can form continuous contact pressure after the insulating protective cover 1 and the insulating base 9 are closed, reducing local gaps in the seal and avoiding water leakage due to insufficient compression or shortening the service life of the seal due to excessive compression.

[0168] In the actual assembly process, first open the insulating protective cover 1, loosen the main line crimping bolt 3 and the branch crimping bolt 7, and separate the upper conductor 4 from the lower conductor 6 or put it in a state where the main cable 5 can be inserted, so that the main line connection area forms an open placement space.

[0169] Subsequently, a section of insulation is stripped at the predetermined branch position of the main cable 5, but the main cable conductor is not cut. The exposed main cable conductor section is placed in the main line support of the lower conductor 6, and then the upper conductor 4 is reinstalled and pre-tightened. This process maintains the original conductor continuity of the main cable 5 and avoids increasing the main line termination interface due to re-connection after cutting.

[0170] Next, tighten the main line crimping bolts 3 according to the designed tightening torque. Under the pressure, the upper conductor 4 deforms towards the main cable conductor and forms an enclosing contact of not less than 270° with the lower conductor 6. The micro-tooth structure breaks off part of the oxide film and increases the actual contact points during the crimping process, so that the contact resistance meets the design requirements. After the main line crimping is completed, close the corresponding protective structure.

[0171] When branch cable 8 needs to be connected, open the transparent protective cover or the corresponding operating area, loosen the branch crimping bolt 7, insert the conductor end of branch cable 8 into the branch connection part of the lower conductor 6, and tighten the branch crimping bolt 7 according to the rated tightening torque. The branch crimping operation is handled by an independent branch crimping force path, and it is not necessary to loosen the main line crimping bolt 3.

[0172] Finally, check the crimping status of the main line, the insertion status of the branch cable 8, and the status of the seals. Close the insulating protective cover 1 and tighten the protective cover screws 2 to complete the branch connection and insulation protection without cutting the main cable 5.

[0173] In the prototype performance verification of this embodiment, the main line crimping bolt 3 and the branch crimping bolt 7 were tightened according to the designed tightening torque, causing the upper conductor 4 to undergo adaptive deformation and form an enclosing contact with the lower conductor 6 with an enclosing angle of not less than 270°. The micro-tooth structure on the contact surface breaks the oxide film on the surface of the main cable conductor and increases the effective contact points during the tightening process. The measured voltage drop at the connection point was no greater than 1.98mV. After applying a short-circuit current impact of 120A / mm² according to the conductor's nominal cross-sectional area, the connection device passed the short-circuit withstand test. These results indicate that the enclosing contact structure can convert the concentrated pressure applied by the main line crimping bolt 3 into a contact pressure distributed circumferentially along the main cable conductor. The micro-tooth structure can further increase the actual conductive contact points, thereby reducing the contact resistance and operating temperature rise at the connection point and improving the electrical stability under short-circuit current impact conditions.

[0174] In embodiments with different conductor materials, the conductive components can be selected from copper, aluminum, or corresponding compatible conductive materials according to the materials of the main cable 5 and the branch cable 8, so as to adapt to different conductor combinations such as copper cables, aluminum cables, or materials that have undergone compatibility treatment.

[0175] Example 3 This embodiment uses a visual protection type connection device for connecting the main cable branches in indoor cable trays or electrical shafts.

[0176] During installation, loosen the protective cover screws 2 located at the four corners of the insulating protective cover 1, remove the transparent insulating protective cover 1, then loosen the main line crimping bolts 3 and remove the upper conductor 4.

[0177] Based on the axial contact length of the conductive components, strip 30-50 mm of insulation at the predetermined branch position of the main cable 5, while maintaining the continuity of the main cable conductor. Place the exposed main cable conductor section directly into the main line support of the lower conductor 6, reinstall the upper conductor 4, and pre-tighten the main line crimping bolts 3.

[0178] When two main line crimping bolts 3 are installed, the pre-tightening and rated tightening torques are applied alternately to the two main line crimping bolts 3 so that the upper conductor 4 deforms more evenly toward the main cable conductor, and avoids the upper conductor 4 from tilting to one side in the initial stage of crimping.

[0179] The upper conductor 4 and the lower conductor 6 together form an enveloping contact of not less than 270° with the main cable conductor. During the compression process, the micro-tooth structure on the contact surface breaks down part of the oxide film on the surface of the main cable conductor, causing the multiple conductors to undergo moderate rearrangement and local micro-plastic deformation, thereby forming a stable airtight contact area.

[0180] After the main line crimping is completed, insert the conductor end of the branch cable 8 into the branch connection part and tighten the branch crimping bolt 7 according to the predetermined tightening torque. Since the main line crimping force path and the branch crimping force path are independent of each other, the crimping force of the main cable 5 will not be released when installing the branch cable 8.

[0181] After completing the connection, reinstall the transparent insulating protective cover 1 and tighten the protective cover screws 2. Operators can inspect the crimping status of the main line and branches through the transparent area. The insulating protective cover 1 and the insulating base 9 provide IP20-level electric shock protection for conductive connection parts, suitable for indoor cable trays and electrical shafts where continuous immersion is not required.

[0182] Example 4 This embodiment uses a multi-level sealed connection device for outdoor, underground, damp equipment areas, or installation environments with a risk of short-term water immersion.

[0183] Before installation, measure the outer diameter of the main cable 5 and the branch cable 8 respectively, and select or remove the corresponding layer of the concentric seal according to the measurement results, so that the through hole size of the seal matches the outer diameter of the main cable 5 or the branch cable 8. Pre-fit the gland and seal onto the main cable 5 and the branch cable 8, and then complete the crimping of the main conductor and the branch conductor.

[0184] The compression ratio of the seal is determined according to the following formula: ε=(d0-h) / d0.

[0185] The peak pressure of the sealed contact is checked according to the following formula: P peak =E rubber ·(1.25ε 1.5＋50ε 6).

[0186] Under operating conditions where the external water pressure is not lower than 0.02 MPa, the peak pressure at the sealing contact should meet the following requirements: P peak >P water,pressure ·S factor .

[0187] At the same time, the total preload provided by the protective cover screw 2 should meet the following requirements: n screw ·F screw,preload ≥∫(L seal )P peak ·w contac t·dl.

[0188] After the conductor crimping is completed, close the insulating protective cover 1 and the insulating base 9, and tighten the screws 2 of each protective cover and the cable gland, so that the seal undergoes axial compression and radial expansion. Check through the transparent area whether the circumferential deformation of the seal is continuous, and confirm that there are no gaps or flips in the elastic sealing strip between the insulating protective cover 1 and the insulating base 9.

[0189] The peelable concentric seal, gland, labyrinth mating edge, and elastic sealing strip together form a multi-level water-blocking path, thereby forming an IP68-level sealing protection when the pressure relationship is met, reducing the possibility of moisture entering the conductive contact area and causing corrosion or a decrease in insulation performance.

[0190] In the sealing performance verification of this embodiment, the multi-stage sealing connection device was assembled, and the protective cover screws 2 and each sealing cap were tightened according to the designed pre-tightening force. This caused the peelable concentric seal to radially press against the outer periphery of the main cable 5 and the branch cable 8, and the elastic sealing strip between the insulating protective cover 1 and the insulating base 9 was continuously compressed. The assembled connection device was subjected to a protective performance test under an external water pressure of not less than 0.02 MPa, and the test results met the IP68 protection requirements. Thus, the compression seal at the cable inlet and outlet, the labyrinth water barrier at the shell mating surface, and the continuous compression seal of the elastic sealing strip together form a multi-stage water-blocking path, reducing the risk of moisture entering the conductive contact area and causing conductor corrosion or insulation performance degradation.

[0191] Example 5 This embodiment uses a flat cable tray type connection device for cable branch connection inside a standard PVC cable tray or metal cable tray.

[0192] During installation, the insulating base 9 is fixed to the bottom of the cable tray using the positioning slot on the insulating base 9 or the two diagonally arranged mounting holes. The two diagonally arranged mounting holes limit the rotation and movement of the insulating base 9 by using fewer mounting positions, thereby reserving more wiring space for the main cable 5 and branch cables 8.

[0193] The main cable 5 passes through the insulating shell along the length of the cable tray. The branch cables 8 enter from the side or oblique side of the insulating shell and extend along the cable tray approximately parallel to the main cable 5. The main cable 5 is placed in the lower conductor 6 by partially stripping the insulation layer without cutting the conductor, and then the upper conductor 4 and the main wire crimping bolts 3 complete the enclosure crimping.

[0194] The total height of the insulating housing is controlled within 50mm to ensure that the connecting device does not protrude significantly beyond the depth of the wire groove. The flat insulating protective cover 1 can be connected to the insulating base 9 using a snap-fit ​​structure, thereby reducing the fastening operation space required at the top of the insulating protective cover 1.

[0195] In this embodiment, the overall height of the insulating housing refers to the vertical distance between the bottom surface of the insulating base 9 and the highest point of the insulating protective cover 1 after the connecting device is assembled. The overall height of the assembled flat cable tray type connecting device is measured and is no greater than 50mm. This height dimension is compatible with the lateral or oblique entry method of the main cable 5 and branch cables 8, reducing the space occupied by the connecting device in the direction perpendicular to the bottom surface of the cable tray, allowing the cable tray cover to close normally, and reducing the bending stress caused by vertical bending of large-section cables.

[0196] The main cable 5 and branch cables 8 are arranged laterally, which reduces sharp bends in large-section cables and allows the cable tray cover to close properly. Through the combination of a low-height insulating shell, a double-layer conductive topology, and lateral cable entry, the space utilization inside the cable tray is improved while ensuring that the main cable 5 is not cut off, has a secure contact, and that the main line and branches are independently compressed.

[0197] Example 6 This embodiment proposes a compact structural design method for a quick connection device for cable branch joints. This method establishes a correlation model between contact resistance and crimping torque, as well as a constraint model between volume and heat dissipation, to design a compact device comprising an insulating protective base, conductive clamps, and a torque crimping assembly. This application integrates the conductor structure, insulation layout, and locking mechanism into a compact design, thereby achieving high-density integration and rapid installation of the cable branch connection device. This method is not merely about reducing geometric dimensions, but rather about finding a Pareto optimal solution that minimizes volume and maximizes electrical performance by establishing an electro-thermal-mechanical multiphysics coupling model. The method includes the following steps: Step 1: This application sets electrical boundary conditions and initializes parameters, mainly consisting of the following two sub-steps: Step 1.1: Define the input parameter vector according to the design requirements. P in Based on the relevant equipment technical parameters, the rated voltage is set. Rated current I load and the diameter range of the main trunk cable .

[0198] Step 1.2: Define the target contact resistance threshold R thAccording to the voltage drop index Set resistance constraints:

[0199] Step 2: Conduct contact surface topology optimization based on the "enclosing engagement" mechanism. To achieve "the clamp engaging with the conductor in an enclosing engagement" manner, a non-Hertzian contact model is constructed, which mainly consists of the following two sub-steps: Step 2.1: Geometric interference calculation: Design the inner radius of the conductive clamp. R clamp Slightly smaller than the cable conductor radius R cond Define the initial radial interference. :

[0200] The resulting circumferential preload stress The distribution function is:

[0201] in E mat The elastic modulus of a conductive material. Φ For angle variables, For the inclusion angle.

[0202] Step 2.2: Contact Area Integral and Resistance Derivation: This application requires an envelope angle Effective contact area A eff Obtained by integrating along the contact arc length:

[0203] in L axial This is the axial length of the wire clamp. To account for surface roughness in the contact coefficient, we substitute it into Holm's contact theory, and the corrected contact resistance is... R c The model is:

[0204] In this step, through iterative optimization L axial and until satisfied .

[0205] Step 3: Bolt tightening torque transfer function and anti-loosening design, establishing a torque-preload transfer model, mainly consisting of the following two sub-steps: Step 3.1: Required normal clamping force F N The reverse solution: the minimum clamping force required to ensure that the conductor undergoes plastic deformation to achieve the "interlocking" state. F N,min Must meet:

[0206] Step 3.2: Apply torque T apply Derivation: Based on mechanical design principles (Motosh formula), input torque T apply With generating preload F bolt The relationship is:

[0207] in: d 2: Thread pitch diameter; : Helix angle; These are the friction coefficients of the threaded pair and the friction coefficients of the supporting surface, respectively. D w : Equivalent diameter of the nut support surface. This step ensures that the rated torque is achieved by adjusting the thread parameters. And utilize the frictional resistance torque generated by the large contact area T fric > T loose To prevent loosening.

[0208] Step 4: Perform the thermo-mechanical co-design of the compact insulating housing, which mainly consists of the following three sub-steps: Step 4.1: To achieve "slim and beautiful" and "compact structure", establish the objective function for minimizing volume:

[0209] Step 4.2: Perform thermal balance constraints: According to Newton's law of cooling, under high current conditions, the heat dissipation power of the casing... P diss Heat generation power needs to be balanced:

[0210] in h conv The natural convection heat transfer coefficient is... S surf This represents the effective heat dissipation surface area of ​​the casing. The minimum surface area required to meet the temperature rise requirement is then calculated, thereby constraining the casing dimensions.

[0211] Step 4.3: Apply insulation safety constraints: According to U rate =1000V, insulation wall thickness t ins Must meet:

[0212] And creepage distance (Refer to IEC 60947 standard).

[0213] Step 5: Calculation of the compression capacity of the IP68-rated sealing structure, mainly consisting of the following three sub-steps: Step 5.1: Calculation of sealing contact pressure: Assume the diameter of the sealing ring is... d 0, the depth of the sealing groove is h Compression ratio According to Lindley's empirical formula, the peak contact pressure generated at the sealing interface... P peak for:

[0214] Step 5.2: Sealing Failure Criteria: To achieve an IP68 protection rating (typically requiring resistance to water pressure above 0.02 MPa), the following must be met:

[0215] Step 5.3: Housing Tightening Force Verification: To prevent the internal sealing reaction force from opening the protective cover, the total tightening force of the protective cover screws is... F cover Must meet:

[0216] in L seal For the sealing circumference, w contact This refers to the contact width.

[0217] Step 6: The rapid assembly implementation process based on the top and bottom split logic mainly consists of the following four sub-steps: Step 6.1: Disassembly and Pre-positioning. Open the outer protective cover, loosen the fastening screws, and separate the internal conductive components from the insulating base.

[0218] Step 6.2: Perform non-destructive trunk connection. Without cutting the main trunk line, strip the insulation layer at the designated location on the main trunk line, place the exposed conductor in the base cable tray, then reinstall the conductor assembly and pre-tighten the screws to complete the electrical contact on the trunk line side.

[0219] Step 6.3: Construct a closed protective system. Cover the main protective cover and tighten the mounting screws to restore the main body of the device to a closed, insulated whole.

[0220] Step 6.4: Perform branch online connection. Remove the top transparent cover, loosen the branch clamp screw, and insert the branch wire into the wire clamp hole. At this time, according to the aforementioned "torque-preload model", apply the rated torque until the wire and the clamp undergo "enclosing engagement" deformation. Finally, replace the transparent cover to complete the installation.

[0221] Step 7: Implementation process of typical structural variants. Based on the above family design, this application includes three typical implementation methods in actual engineering, each corresponding to different protection and installation requirements: Implementation Method 1: Protective Assembly (Applicable to Indoor Cable Trays and Shafts), mainly consists of the following four sub-steps: First, separate the core body. Loosen the locking screws at the four corners of the shell and open the transparent protective cover; further loosen the fixing bolts of the internal conductor and remove the conductive clamp assembly from the insulating base.

[0222] Secondly, perform non-destructive insertion of the main line. Without cutting the main line cable, strip a section of insulation about 30-50mm long (the specific length depends on the actual operation requirements) and embed the exposed conductor into the pre-made groove of the insulating base.

[0223] Next, the conductor is reset and engaged. The conductive clamp assembly is then reattached to the main line, and the bolts on both sides are tightened alternately. At this point, the specially designed "enclosing" jaws, under the axial force of the bolts, pierce the oxide film on the conductor surface and produce a small amount of plastic deformation, forming an airtight electrical connection.

[0224] Finally, perform branch connection and enclosure. Insert the branch cable into the upper cable hole and tighten it with the specified torque; finally, cover it with the transparent protective cover to complete the IP20 protection installation.

[0225] Implementation Method Two: High-Grade Sealed Assembly (Suitable for Outdoor and Damp Cable Trench) mainly consists of the following four sub-steps: First, select the appropriate seals. Before operation, cut or select rubber sealing rings with corresponding bore diameters based on the actual outer diameters of the main line and branch lines.

[0226] Secondly, pre-install the sealing components. Before stripping the cable, first put the sealing cap and sealing ring onto both ends of the cable in sequence.

[0227] Next, close and pressurize the cavity. After completing the internal conductive connections, close the upper and lower housings. A key step is to tighten the sealing caps at the cable inlet and outlet.

[0228] Finally, a sealing test is performed. Observe the deformation of the sealing ring under pressure to ensure that the sealing medium tightly wraps around the cable root without any visible gaps, thereby achieving the IP68 protection standard and preventing moisture intrusion.

[0229] Implementation Method 3: Concealed Cable Tray Installation (Suitable for Indoor Building Cabling), mainly consists of the following three sub-steps: First, perform spatial positioning. Directly use the positioning slots or screw holes on the bottom of the device to fix the insulating base to the base plate of the PVC cable tray or metal cable rack.

[0230] Secondly, flat wiring is implemented. Due to the low-profile design, both main lines and branch lines are introduced parallel to the longitudinal direction of the cable tray. After stripping and connecting, the wires will not bulge, ensuring that the cable tray cover can close smoothly.

[0231] Finally, apply insulation. Install a dedicated flat protective cover, which uses a snap-on structure for quick locking, eliminating the need for additional screws and significantly improving the efficiency of batch construction.

[0232] As can be seen from the above embodiments, the core of this application is not a single T-shaped branch structure or a single bolt crimping structure, but rather a set of synergistic technical relationships formed around the uninterrupted branch connection of the main cable: a separable upper and lower structure provides lateral, non-destructive insertion conditions for the main cable; mismatched curvature and deformable upper conductor convert bolt loading into circumferential containment pressure; a micro-tooth structure forms multi-point membrane-breaking contact in the circumferential containment area; an integrated lower conductor forms a continuous conductive path from the main line to the branch line; and independent main line and branch crimping structures ensure that the two crimping states do not interfere with each other. These technical features together constitute a stable, low-resistance branch connection mechanism under uninterrupted main cable conditions.

[0233] As can be seen from the above embodiments, the advantages of this application compared with the prior art are as follows: This application utilizes the compressive deformation of the upper conductor 4 and the enveloping contact formed between the upper conductor 4 and the lower conductor 6 to distribute the concentrated pressure applied by the main line crimping bolt 3 circumferentially along the main cable conductor. Furthermore, the micro-tooth structure on the contact surface breaks down the oxide film on the conductor surface, increasing the number of effective contact points. Prototype performance verification shows that the measured voltage drop at the connection point is no greater than 1.98mV, and it can pass a 120A / mm² short-circuit current impact test. This helps reduce the contact resistance and operating temperature rise at the connection point, improving the electrical stability and short-circuit withstand capability of the connection device.

[0234] To address the issues of traditional power distribution schemes requiring the cutting of the main line, which damages cable integrity, or occupying significant installation space, this application employs a compact, integrated insulating housing and a split-type installation logic, enabling rapid on-site branch connections without cutting the main cable. This design allows for flexible operation in confined spaces (such as underground cable trenches and vertical cable trays). On-site construction only requires stripping the main line insulation layer for installation, without cutting the cable or requiring special tools. Compared to traditional busbar trunking or pre-branched cable solutions, this significantly reduces labor intensity and time, and effectively saves on overall project costs.

[0235] To overcome insulation aging, corrosion failure, and loosening caused by harsh environments, this application employs an anti-loosening and shock-resistant structure based on a torque transmission model and multi-level sealing protection technology. The main body of the device uses high-strength insulation materials that are anti-aging, impact-resistant, and flame-retardant up to UL94V-0. Combined with a specially calculated sealing ring structure, the device not only possesses excellent mechanical strength and anti-loosening and shock-resistant capabilities but also achieves protection levels ranging from IP20 to a maximum of IP68. This completely solves the waterproof insulation problems in outdoor, underground, humid, and underwater environments, ensuring long-term reliability for all-weather operation.

[0236] This application combines a transparent cover design with a high-strength bolt anti-loosening and seismic-resistant structure, enabling the device to be visually inspected after installation. Furthermore, it eliminates the need for frequent maintenance compared to traditional wiring methods during long-term operation, significantly reducing maintenance costs. Simultaneously, through modular sealing components and diverse installation interfaces (suspended / fixed / embedded in cable trays), this application is applicable to all scenarios, from indoor cable trays to outdoor underground installations (with IP68 sealing), solving the problem of traditional T-junction boxes being bulky and unable to adapt to confined spaces. Compared to the single-form T-junction boxes in existing technologies, this application, through modular parameter adjustments and guided by the same mathematical model (contact resistance-thermodynamic model), derives four structural forms: open heat dissipation, compact protection, full sealing, and flat integration. This solves the problem that a single connection device cannot simultaneously address installation in confined spaces, protection in harsh outdoor environments, and aesthetically pleasing integrated cabling within buildings.

[0237] Example 7 This embodiment is a further implementation based on the cable branch connector quick connection device described in Embodiment 1. Similar to Embodiment 1, the quick connection device in this embodiment still includes an insulating shell, a conductive connection assembly, a main line crimping assembly, and a branch crimping assembly. The conductive connection assembly includes an upper conductor 4 and a lower conductor 6. The lower conductor 6 includes an integrally formed main line support portion and a branch connection portion. The main cable 5 is disposed between the upper conductor 4 and the lower conductor 6, and forms the aforementioned enclosed conductive contact through the main line crimping assembly. The branch cable 8 forms an electrical connection with the branch connection portion of the lower conductor 6 through the branch crimping assembly.

[0238] Unlike Embodiment 1, this embodiment, while maintaining the aforementioned quick-connect structure and its clamping force relationship, further incorporates an intelligent sensing unit 10. This unit acquires the main circuit current of the trunk cable 5 and the temperature of the conductive connection area corresponding to the main line clamping position, and wirelessly transmits the acquired operating parameters to an external acquisition device or concentrator. Thus, this embodiment, while achieving uninterrupted quick branch connection of the trunk cable 5, further enables online sensing of the operating status of the formed conductive connection position.

[0239] like Figure 3 and Figure 4 As shown, the intelligent sensing unit 10 includes an openable installation structure 11, an energy harvesting unit 12, a current sampling unit 13, a temperature sampling unit 14, an elastic clamping member 15, a processing unit 16, a wireless communication unit 17, an antenna 18, and a status indicator 19.

[0240] The openable installation structure 11 constitutes the main support and installation structure of the intelligent sensing unit 10. It can be fitted radially outside the main cable 5 in the open state and surround the main cable 5 when closed. Therefore, when installing the intelligent sensing unit 10, it is not necessary to cut the main cable 5 or have the ends of the main cable 5 pass sequentially through the intelligent sensing unit 10, which is beneficial for compatibility with the installation method of the main cable without interrupting branch connections in this application.

[0241] The energy harvesting unit 12 and the current sampling unit 13 are respectively installed on the main cable 5. The energy harvesting unit 12 obtains induced electrical energy by sensing the power frequency magnetic field generated around the main cable 5 by the alternating current, and after rectification and voltage regulation, provides operating power to the processing unit 16, temperature sampling unit 14, wireless communication unit 17, and status indicator 19 in the intelligent sensing unit 10. The current sampling unit 13 is used to acquire the sampling signal corresponding to the main circuit current in the main cable 5 and transmit the sampling signal to the processing unit 16.

[0242] In some embodiments, the energy harvesting unit 12 and the current sampling unit 13 each include a magnetic induction structure corresponding to the trunk cable 5; alternatively, depending on the specific structural configuration, the energy harvesting function and the current detection function may share a portion of the magnetic circuit structure. Both the energy harvesting unit 12 and the current sampling unit 13 are disposed within the openable mounting structure 11, so that when the openable mounting structure 11 is closed, the corresponding magnetic induction structure can form a magnetic circuit suitable for electromagnetic induction around the trunk cable 5.

[0243] The temperature sampling unit 14 is positioned corresponding to the conductive contact area. The temperature sampling unit 14 includes a temperature probe, and an elastic clamping member 15 is disposed between the temperature probe and the hinged mounting structure 11, providing a continuous elastic force to the temperature probe toward the conductive part to be tested. The elastic clamping member 15 ensures that the temperature sampling unit 14 remains in contact with the conductive part to be tested, reducing the possibility of the temperature probe detaching from the test location due to installation gaps, mechanical vibration, or dimensional tolerances.

[0244] Furthermore, the temperature sampling unit 14 is preferably set in the conductive voltage connection area directly corresponding to the clamping position of the main line, so that the temperature probe detects not the indirect temperature of the outer surface of the insulation layer of the main cable 5, but the temperature of the crimped area that forms an electrical connection with the main cable 5 and the conductive connection component. This allows for more direct acquisition of the temperature rise information at the crimped position that affects the conductivity reliability of the cable branch joint.

[0245] The processing unit 16 and the wireless communication unit 17 are disposed within the internal accommodating space of the openable mounting structure 11. The processing unit 16 is electrically connected to the current sampling unit 13, the temperature sampling unit 14 and the wireless communication unit 17 respectively, and is used to receive the main circuit current data collected by the current sampling unit 13 and the temperature data of the crimping area collected by the temperature sampling unit 14, and process the data.

[0246] The wireless communication unit 17 is connected to the antenna 18. The current data, temperature data, and corresponding status information processed by the processing unit 16 can be transmitted to an external acquisition device or concentrator via the wireless communication unit 17 and the antenna 18. In one embodiment, the wireless communication unit 17 uses LoRa wireless communication; in other embodiments, Bluetooth or other low-power wireless communication methods may also be used.

[0247] The status indicator 19 is located in a visible position on the outside of the hinged mounting structure 11 and is connected to the processing unit 16. The status indicator 19 may include one or more indicator lights to indicate the power supply status, data acquisition status, wireless communication status, and / or abnormal alarm status of the intelligent sensing unit 10, so that on-site operators can intuitively determine whether the intelligent sensing unit 10 is in normal working condition.

[0248] In this embodiment, the intelligent sensing unit 10 corresponds to the quick-connect structure described in Embodiment 1 in terms of installation and detection objects. The openable installation structure 11 is compatible with the installation method of continuous connection of the main cable 5 in Embodiment 1, enabling the intelligent sensing unit 10 to be installed without cutting the main cable 5. The current sampling unit 13 uses the main circuit current flowing through the quick-connect device as the detection object. The temperature sampling unit 14 is set by the elastic clamping member 15 corresponding to the main line clamping position formed by the upper conductor 4, lower conductor 6 and main cable 5 in Embodiment 1, to obtain the operating temperature of the enclosed conductive contact area. Therefore, the current parameters and temperature parameters collected by the intelligent sensing unit 10 both correspond to the quick branch connection state formed in Embodiment 1.

[0249] With the above structure, the energy harvesting unit 12, the current sampling unit 13, the temperature sampling unit 14, the processing unit 16, and the wireless communication unit 17 are integrated into the same open-type installation structure 11. Without additionally cutting the main cable 5, it can complete inductive energy harvesting, main circuit current acquisition, crimping area temperature acquisition, and wireless data transmission, thereby adapting the intelligent sensing function to the uninterrupted rapid branch connection method of this application.

[0250] like Figure 4 As shown, the intelligent sensing unit 10 is installed on the outer periphery of the main cable 5 and is arranged adjacent to the quick connection device. The quick connection device is used to realize the uninterrupted branch connection between the main cable 5 and the branch cable 8. The intelligent sensing unit 10 is used to acquire the main circuit current and the temperature of the conductive voltage connection area related to the operating status of the branch connection position.

[0251] The quick-connect device includes a main line crimping bolt 3, an upper conductor 4, a main cable 5, a lower conductor 6, a branch crimping bolt 7, a branch cable 8, and an insulating base 9. After the insulation layer of the main cable 5 is partially stripped, its exposed conductor is positioned between the upper conductor 4 and the lower conductor 6. The main line crimping bolt 3 presses the upper conductor 4 towards the lower conductor 6, thereby forming the aforementioned enclosed conductive contact. The branch cable 8 is pressed against the branch connection portion of the lower conductor 6 by the branch crimping bolt 7.

[0252] The intelligent sensing unit 10 is surrounded by a hinged mounting structure 11 around the main cable 5. During installation, the hinged mounting structure 11 opens radially outward from the main cable 5 and is fitted onto the main cable 5. After being adjusted to a predetermined monitoring position close to the quick-connect device, it closes and secures itself. This installation process does not require releasing the main line crimping bolts 3 or the branch crimping bolts 7, nor does it require cutting the main cable 5.

[0253] The temperature sampling unit 14 is positioned corresponding to the main line clamping position of the quick-connect device via the elastic clamping member 15. The elastic clamping member 15 applies an elastic force to the temperature sampling unit 14 toward the conductive voltage connection area, keeping the temperature sampling unit 14 in contact with the conductive voltage connection area or the conductive part directly thermally coupled thereto, so as to collect the actual operating temperature of the crimped position between the main cable 5 and the upper conductor 4 and / or the lower conductor 6.

[0254] Since the current in the main cable 5 directly affects the Joule heat generated in the crimping area during operation, the intelligent sensing unit 10 simultaneously acquires the main circuit current and the temperature of the crimping area. This provides basic monitoring data to distinguish between normal load temperature rise and abnormal temperature rise at the connection location. For example, when the main circuit current is within the normal range but the temperature of the crimping area continues to rise, the corresponding current and temperature data can be sent to an external acquisition device for subsequent operational status analysis.

[0255] The intelligent sensing unit 10 achieves wireless communication with an external acquisition device or concentrator via antenna 18. The status indicator 19 displays the operating status of the intelligent sensing unit 10 on-site. When the processing unit 16 determines that the main circuit current exceeds a preset overcurrent threshold and / or the temperature of the conductive voltage connection area exceeds a preset overtemperature threshold, it can actively send corresponding abnormal alarm information to the external acquisition device via the wireless communication unit 17 and antenna 18, and output the corresponding status indication via the status indicator 19.

[0256] Therefore, in this embodiment, the intelligent sensing unit 10 is not used as an independent monitoring device unrelated to the quick connection device. Instead, the temperature detection position of the intelligent sensing unit 10 is directly corresponding to the main line clamping position in the quick connection device that affects the conductivity reliability. The opening and closing installation method of the intelligent sensing unit 10 is matched with the uninterrupted installation method of the main cable of the quick connection device. Thus, on the basis of realizing the uninterrupted quick branch connection of the main cable 5, the operating status of the formed conductive connection position is monitored online.

[0257] In summary, this embodiment does not change the basic quick connection relationship formed by the upper conductor 4, lower conductor 6, main line crimping assembly, and branch crimping assembly in Embodiment 1. Instead, it further incorporates an intelligent sensing unit 10 based on this connection relationship. The enclosed contact structure in Embodiment 1 is used to form a stable main line conductive connection, while the intelligent sensing unit 10 uses the main circuit current and crimping area temperature corresponding to this conductive connection as monitoring objects. This allows the quick connection function and the connection status sensing function to work together around the same main line clamping position.

[0258] The above are merely preferred embodiments of this application and do not constitute any limitation on this application. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of this application shall still fall within the protection scope of the technical solution of this application.

[0259] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above embodiments, those skilled in the art can still modify or make equivalent substitutions to the specific implementation schemes of this application. Such modifications or equivalent substitutions do not depart from the spirit and scope of this application and are all within the protection scope of the claims of this application.

[0260] The above content provides a further detailed description of this application and should not be construed as limiting the specific implementation methods of this application to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of this application, and all such deductions or substitutions should be considered as falling within the scope of protection defined by the submitted claims.

Claims

1. A quick-connect device for cable branch joints, characterized in that, Includes insulating housing, conductive connection assembly, main line crimping assembly, and branch crimping assembly; The insulating housing includes an insulating base and an insulating protective cover detachably connected to the insulating base. The insulating housing is provided with a main channel for the trunk cable to pass through and a branch channel for the branch cable to pass through. The upper side of the insulating base is provided with a cable placement opening communicating with the main channel. The conductive connection assembly is disposed within the insulating housing and includes an upper conductor and a lower conductor that are arranged opposite to each other and separable. The lower conductor is an integral conductor and includes a main line support portion and a branch connection portion integrally extended from the main line support portion. A main line clamping position is formed between the upper conductor and the main line support portion so that the main cable with partially stripped insulation layer and not cut can be laterally inserted into the main line clamping position through the cable placement opening. The upper conductor has a first arc-shaped contact surface facing the main line support portion, and the main line support portion has a second arc-shaped contact surface facing the upper conductor. At least one of the first arc-shaped contact surface and the second arc-shaped contact surface has an inner arc radius smaller than the outer circle radius of the exposed conductor of the main cable that is adapted to it when it is not compressed. The main line crimping assembly is used to apply a clamping force toward the main line support portion to the upper conductor, causing the upper conductor to undergo adaptive deformation, and to form an interference fit contact between the first arc-shaped contact surface and the second arc-shaped contact surface and the exposed conductor of the trunk cable, wherein the fit contact has an fit angle of not less than 270° in a cross section perpendicular to the axis of the trunk cable. The branch connection section is provided with a branch connection position for accommodating the exposed conductor of the branch cable, and the branch crimping assembly is used to crimp the exposed conductor of the branch cable to the branch connection section; The main line crimping assembly and the branch crimping assembly are set independently of each other, so that the main cable and the branch cable form independent crimping force paths respectively.

2. The quick-connect device for cable branch joints according to claim 1, characterized in that, At least one of the first arc-shaped contact surface and the second arc-shaped contact surface is provided with a plurality of micro-tooth structures distributed at intervals along the axial and / or circumferential directions of the trunk cable; When both the first arc-shaped contact surface and the second arc-shaped contact surface are provided with the micro-tooth structure, the micro-tooth structures of the two are staggered along the circumference of the trunk cable so that the upper conductor undergoes adaptive deformation and forms the enclosing contact. During this process, the micro-tooth structures located at different circumferential positions respectively form a pressing contact with the exposed conductor of the trunk cable.

3. The quick-connect device for cable branch joints according to claim 1, characterized in that, The branch connection part is integrally extended from the side of the main line support part. The branch connection part is provided with a branch connection hole for inserting the branch cable. The axis of the branch connection hole intersects with the axis of the main line channel so that the main cable and the branch cable form a T-shaped connection. Preferably, the main line crimping assembly includes at least two main line crimping bolts spaced apart along the axial direction of the trunk cable, and the at least two main line crimping bolts respectively apply a clamping force to the upper conductor so that the upper conductor deforms uniformly toward the main line support along its axial direction; The thread helix angle of the main line crimping bolt is less than the equivalent friction angle of the corresponding thread pair, so that the main line crimping bolt forms a thread self-locking under the crimped state.

4. The quick-connect device for cable branch joints according to claim 1, characterized in that, The insulating housing includes an insulating base and an insulating protective cover covering the insulating base. At least a portion of the insulating protective cover is made of transparent insulating material, or the insulating protective cover is provided with a transparent observation window for observing the insertion position and crimping status of the main cable and the branch cable. Preferably, the cable inlet and outlet of the main channel and the branch channel are respectively provided with multi-layer concentric sealing rings or peelable sealing rings and sealing caps for axial compression of the sealing rings. The mating surface of the insulating base and the insulating protective cover is provided with a labyrinth waterproof groove, and the labyrinth waterproof groove is provided with an elastic sealing strip.

5. The quick-connect device for cable branch joints according to claim 1, characterized in that, The bottom of the insulating housing is provided with two mounting holes for fixing the quick connection device to the mounting base, and the two mounting holes are spaced apart along the diagonal direction of the bottom of the insulating housing; Preferably, the insulating housing is a flat rectangular housing, and the main cable channel and the branch cable channel are both located on the side of the insulating housing so that the main cable and the branch cable are introduced along the side of the insulating housing, and the overall height of the insulating housing is less than 50mm.

6. The quick-connect device for cable branch joints according to claim 1, characterized in that, It also includes an intelligent sensing unit, which includes an openable installation structure, an energy harvesting unit, a current sampling unit, a temperature sampling unit, a processing unit, and a wireless communication unit. The opening and closing installation structure can be opened and surrounded around the main cable and then closed, so that the intelligent sensing unit can be installed on the main cable without cutting off the main cable. The energy harvesting unit is used to sense the power frequency magnetic field around the main cable and obtain induced electrical energy to power the intelligent sensing unit. The current sampling unit is used to collect the main circuit current of the main cable, and the temperature sampling unit is used to collect the temperature of the conductive voltage connection area corresponding to the clamping position of the main line. The processing unit is connected to the current sampling unit, the temperature sampling unit and the wireless communication unit respectively, and is used to acquire the main circuit current and the temperature of the conductive voltage connection area, and to send the main circuit current and the temperature of the conductive voltage connection area to an external acquisition device through the wireless communication unit; Preferably, the energy harvesting unit includes a mutual inductance energy harvesting structure, a rectifier circuit, and a voltage regulator circuit. The mutual inductance energy harvesting structure is disposed on the outer periphery of the main cable and is used to sense the power frequency magnetic field around the main cable. The rectifier circuit and the voltage regulator circuit are used to rectify and regulate the induced electrical energy generated by the mutual inductance energy harvesting structure. The temperature sampling unit includes a temperature probe and an elastic clamping member. The elastic clamping member is used to apply an elastic force to the temperature probe toward the conductive connection assembly, so that the temperature probe is continuously pressed against the conductive part corresponding to the clamping position of the main line, so as to directly collect the temperature of the conductive connection area. Preferably, the wireless communication unit is a LoRa wireless communication unit, and the wireless communication unit is connected to an antenna for transmitting and / or receiving wireless signals; The processing unit is used to compare the main circuit current with a preset overcurrent threshold and compare the temperature of the conductive voltage connection area with a preset overtemperature threshold. When the main circuit current exceeds the preset overcurrent threshold and / or the temperature of the conductive voltage connection area exceeds the preset overtemperature threshold, the processing unit sends corresponding alarm information to the external acquisition device through the wireless communication unit and the antenna. The intelligent sensing unit also includes a status indicator connected to the processing unit, the status indicator being used to indicate the working status of the intelligent sensing unit.

7. A design method for a quick-connect device for cable branch joints, characterized in that, include: Obtain the structural parameters, electrical operating parameters, and installation space parameters of the main and branch cables to be connected, and determine the target contact resistance between the conductive connection components and the main cable based on the rated current and allowable contact voltage drop; Using the outer radius of the exposed conductor of the main cable as a reference, the uncompressed inner arc radius of the arc-shaped contact surface of at least one of the upper and lower conductors is set to be smaller than the outer radius of the exposed conductor to form an initial radial interference. The circumferential contact pressure distribution under the compression state is determined according to the initial radial interference, the axial length of the contact surface and the target containment angle, wherein the target containment angle is not less than 270°. The effective conductive contact area and the number of effective contact points are determined based on the circumferential contact pressure distribution, and the normal clamping force required to form the enclosing contact is determined in reverse based on the effective conductive contact area, the number of effective contact points, and the target contact resistance. The bolt preload and rated applied torque of the main line crimping assembly are determined based on the normal clamping force, and the thread helix angle of the crimping bolt in the main line crimping assembly is made smaller than the equivalent friction angle of the corresponding thread pair. The lower conductor is designed as an integral conductor including a main line support and a branch connection, and a main line crimping assembly and a branch crimping assembly corresponding to the main line support and the branch connection are respectively provided, so that the main line current and the branch current are transmitted through the integral conductor, and the main cable and the branch cable form independent crimping force paths. With minimizing the volume of the insulating shell as the optimization objective, and with contact resistance, allowable temperature rise, effective heat dissipation area, electrical clearance, and creepage distance as constraints, the structural parameters of the conductive connection assembly, the main line crimping assembly, the branch crimping assembly, and the insulating shell are iteratively adjusted to obtain the target structural parameters.

8. The design method according to claim 7, characterized in that, Determining the curvature of the contact surface between the upper conductor and the lower conductor includes: The inner arc radius of the contact surface of at least one of the upper conductor and the lower conductor in the uncompressed state is set to be smaller than the outer circle radius of the exposed conductor of the trunk cable to form an initial radial interference. The circumferential pressure distribution of the contact surface is determined based on the initial radial interference, the elastic modulus of the conductor material, and the containment angle. By adjusting the inner radius of the contact surface, the axial contact length, and the containment angle, the circumferential pressure distribution can meet the requirements of the target contact resistance. Preferably, establishing the correlation between the contact resistance and the normal clamping force includes: Based on the material resistivity, material hardness, effective conductive contact area, normal clamping force, and number of effective contact points of the exposed conductor of the main cable and the conductive connection component, determine the shrinkage resistance and film resistance between the exposed conductor of the main cable and the conductive connection component. The contact resistance is determined based on the shrinkage resistance and the membrane resistance; The required normal clamping force is determined in reverse based on the target contact resistance, and the number of effective contact points is increased by setting micro-tooth structures on the contact surfaces of the upper conductor and / or the lower conductor.

9. The design method according to claim 7, characterized in that, Determining the structural parameters and rated applied torque of the main wire crimping assembly includes: Based on the thread pitch diameter, thread helix angle, thread pair friction coefficient, bearing surface friction coefficient, and bearing surface equivalent friction radius of the crimp bolt, establish the transmission relationship between the rated applied torque and the bolt preload. The bolt preload and the rated applied torque are determined based on the normal clamping force. The thread helix angle of the crimping bolt is set to be less than the equivalent friction angle of the corresponding thread pair, so that the crimping bolt forms a thread self-locking state under the crimped state; The structural parameters of the insulating shell are coupled and optimized, including: The heat generation power of the conductive connection assembly is determined based on the rated current and the contact resistance. The minimum heat dissipation area required for the insulating shell is determined based on the effective heat dissipation area of ​​the insulating shell, the natural convection heat transfer coefficient, and the allowable temperature rise. The minimum electrical clearance inside the insulating housing is determined based on the rated voltage, air breakdown field strength, and safety factor, and the minimum creepage distance of the insulating housing is determined based on the preset insulation standard. The external dimensions of the insulating housing are reduced while meeting the requirements of minimum heat dissipation area, minimum electrical clearance, and minimum creepage distance.

10. The design method according to claim 7, characterized in that, Also includes: The wire diameter, sealing groove depth, and sealing compression ratio of the sealing ring at the cable inlet and outlet are determined according to the target protection level of the quick-connect device. The contact pressure at the sealing interface is determined based on the sealing compression ratio, and the contact pressure is made greater than the external water pressure corresponding to the target protection level. The required locking force for the insulating protective cover is determined based on the sealing circumference, sealing contact width, and contact pressure, and the number, arrangement, and rated locking torque of the protective cover screws are determined based on the locking force.

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