Anti-loosening power box branching connector and wiring method

Abstract

The invention discloses an anti-loosening power box branching connector. The anti-loosening power box branching connector comprises a welding strengthening shell assembly, a laser fixing core base assembly, a double-loosening-preventing locking assembly and a welding sealing protection assembly. The welding strengthening shell assembly is of a three-section structure and is integrally connected through inertia friction welding, and a composite anti-corrosion coating is arranged on the surface. According to the laser fixed core base assembly, stable connection of an insulating base, a conductive terminal and a shell is achieved through hot melting and laser spot welding, and limiting is strengthened by matching with circumferential laser welding of an inclination clamping angle. The dual anti-loose locking assembly adopts an elastic washer pre-tightening and laser spot welding backstop design, and the welding sealing protection assembly realizes IP67 protection through laser micro-melting sealing groove and weld joint repair welding; meanwhile, the invention also provides a wiring method based on the branching connector. The problems that a traditional branching connector is prone to loosening, poor in sealing performance and low in reliability are solved, and the branching connector has the advantages of being anti-loosening, resistant to corrosion and easy to maintain and is suitable for outdoor power boxes, industrial power boxes and other scenes.

Description

Technical Field

[0001] This invention belongs to the field of power connector technology, specifically relating to an anti-loosening power box branch connector and wiring method. Background Technology

[0002] In outdoor power boxes, industrial distribution cabinets, and other applications, it is often necessary to divide a main incoming line into multiple branch lines. Traditional branch line connectors mostly use bolt crimping, clamp locking, or simple plug-in structures. During long-term operation, especially in harsh environments such as vibration, large temperature variations, high humidity, or high salt spray, these structures reveal numerous problems: 1) Poor anti-loosening capability: Mechanical vibration easily leads to loosening of bolts, clamps, and other fasteners, causing increased contact resistance, overheating, or even power outages; 2) Insufficient sealing performance: Segmented shells or simple sealing rings are prone to water leakage and condensation due to aging and deformation, leading to decreased insulation and short-circuit risks; 3) Low long-term reliability: The internal conductors and insulators are often crimped or glued, which can easily create micro-gaps under thermal stress and vibration, leading to discharge or connection failure; 4) Inconvenient maintenance: The installation status is not visible, fault diagnosis is difficult, and traditional anti-loosening structures are difficult to restore to their original performance after disassembly.

[0003] Although existing technologies have attempted to use higher-quality sealing materials or add locking components, they have failed to fundamentally solve the problems of loosening and sealing failure caused by unreliable connection processes. A search revealed Chinese patent application number 202423051353.2, which discloses an anti-loosening signal cable connector fastener. This fastener includes a signal cable harness with several signal branch harnesses inside. A mating interface is fixedly installed on the top surface of the signal cable harness, and a limiting groove is formed on the top surface of the mating interface. A connecting component is positioned above the signal cable harness and is used to connect the signal cable harness connector and the signal cable harness interface. A cutting and melting component is positioned inside the limiting groove and is used to cut the signal branch harnesses inside the signal cable harness connector and connect the signal branch harnesses inside the signal cable harness connector to the signal branch harnesses inside the signal cable harness interface.

[0004] This application differs from the aforementioned prior art documents in the following ways:

[0005] The shell in the prior art is a split type, consisting of three parts: signal harness, docking interface, and docking connector. The technology mainly uses hot-melt copper wire to complete the electrical connection, and the core components are concentrated in the limiting groove of the docking interface, without complex shell encapsulation. This application adopts a three-section welded reinforced shell with a modular laser-fixed core seat nested inside, equipped with a double anti-loosening locking component and a welded sealing protection component. It also provides a specific process flow, that is, the shell is integrally formed by inertial friction welding, and the internal core seat, conductive terminals and other key components are formed by laser spot welding to form a metallurgical bond, with an elastic pre-tightening mechanism. Compared with the other party's patent, the structure and process are more complex.

[0006] Therefore, there is an urgent need for a power box branch connector and its corresponding operating method that innovates in structural design and connection technology, possesses extremely high anti-loosening capability, long-term sealing stability, and convenient maintenance. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing technologies and provides an anti-loosening electrical box branch connector and wiring method. It strengthens the structural connection through innovative welding technology to prevent loosening and leakage. Secondly, it realizes modular and visual design, which facilitates installation, maintenance and quality traceability. Finally, it provides a standardized and reliable wiring operation procedure that matches the connector structure.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A type of anti-loosening electrical box branch connector, comprising:

[0010] The welded reinforced outer shell assembly is a sealed shell formed by integrally connecting segmented structures through friction welding.

[0011] A laser-fixed core assembly is disposed within the welded reinforced outer shell assembly, including an insulating base and conductive terminals embedded in the insulating base. The conductive terminals and the insulating base, as well as the insulating base and the welded reinforced outer shell assembly, are fixedly connected by a laser welding process.

[0012] A dual anti-loosening locking assembly is provided at the branching and mating end of the welded reinforced shell assembly to achieve mechanical locking with the mating connector;

[0013] A welded sealing and protective assembly includes a sealing groove and a sealing ring disposed on a welded reinforced shell assembly. Further, the welded reinforced shell assembly includes a housing fixed end, a connecting shaft, and a branch connection end integrally connected by inertial friction welding. The surface of the welded reinforced shell assembly is provided with an anti-corrosion coating, and the friction weld area is treated with laser remelting. The joint is reinforced by laser sealing weld repair. The inner wall of the welded reinforced shell assembly has a keyway. The housing fixed end is a flange structure with mounting holes. The outer periphery of the branch connection end has external threads. The area on the connecting shaft corresponding to the installation position of the insulating base has a transparent observation window, the edge of which is sealed to the connecting shaft by laser sealing welding. Further, the insulating base is made of aluminum nitride ceramic, and its outer wall has positioning protrusions adapted to the keyway on the inner wall of the welded reinforced shell assembly. After the conductive terminal is pre-fixed by hot melting, its outer periphery is reinforced by at least one laser weld point to the insulating base. Furthermore, the inner wall of the welded reinforced outer shell assembly is provided with an installation groove; the laser-fixed core assembly also includes an angled retaining angle; after the angled retaining angle is embedded in the installation groove, the root of the angled retaining angle is fixedly connected to the inner wall of the welded reinforced outer shell assembly through a circumferential laser weld. Furthermore, the dual anti-loosening locking assembly includes a locking nut that mates with the external thread of the branch connection end, and a wave-shaped elastic washer disposed between the locking nut and the end face of the connector; at least one laser anti-loosening weld point is provided at the meshing surface of the locking nut and the external thread of the branch connection end. Furthermore, the sealing groove includes a front annular sealing groove and a rear annular sealing groove located at both ends, and the groove edges of the sealing groove are laser micro-melted to form a smooth sealing surface.

[0014] Based on the above-mentioned anti-loosening power box branch connector, the present invention also provides a wiring method for the anti-loosening power box branch connector, including the following steps: S1. Preparation work: inspect the connector and cable, and pre-treat the mounting surface; S2. Fix the box-type fixed end of the branch connector to the power box body through the flange, and perform non-destructive testing on the friction weld area; S3. Select the laser fixing core seat assembly with the corresponding number of cores according to the branching requirements, and insert it into the mounting through hole of the welded reinforced shell assembly until it is engaged, wherein the joint between the laser fixing core seat assembly and the welded reinforced shell assembly is reinforced by laser spot welding; S4. Insert the incoming conductor and the branch conductor into the conductive terminals of the laser fixing core seat assembly respectively and press them tightly; S5. Install the sealing ring and the double anti-loosening locking assembly at the branching connection end, and lock it according to the preset torque, wherein the locking nut is laser anti-loosening spot welded;

[0015] S6. Perform sealing tests, insulation performance tests, and welding quality re-inspections on the assembled branch connectors.

[0016] Further, the laser spot welding reinforcement parameters in step S3 are: power 150-250W, with at least 3 uniform spot welds along the joint between the core seat and the outer shell; the laser anti-loosening spot welding parameters in step S5 are: power 80-120W, with at least 2 symmetrical spot welds on the locking nut and thread engagement surface. Further, the non-destructive testing in step S2 uses an ultrasonic flaw detector with a detection frequency of 2.0-2.5MHz; the welding quality re-inspection in step S6 includes checking the integrity of all laser welds with a magnifying glass and tracing welding parameters using a laser power meter. Further, it also includes:

[0017] Step S7: For unused branch ports, tighten the dust cap with sealing gasket and perform laser spot welding at least 2 points along the contact area between the dust cap and the end face of the port.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The friction welding process integrates the outer shell into a single unit, eliminating component loosening and movement caused by vibration and thermal cycling, thus improving the anti-loosening life and reliability. Simultaneously, friction welding achieves a seamless connection between the outer shell and the main body. Combined with laser welding of critical seams, laser-micro-melting treated sealing grooves, and welded sealing rings, a dual barrier of body sealing and interface sealing is constructed, achieving a stable IP67 protection rating and strong adaptability to extreme environments.

[0020] 2. The modular core base supports quick replacement; the transparent observation window makes the installation status and solder joint integrity clear at a glance; laser marking enables traceability of process parameters and quality information. During maintenance, necessary anti-loosening solder joints can be removed non-destructively by grinding, balancing reliability and maintainability;

[0021] 3. The provided wiring operation method not only has clear steps, but also integrates quality control links such as non-destructive testing, laser parameter calibration, and post-weld re-inspection into the process, forming a closed loop of operation-testing-verification, ensuring that every installed joint can achieve the design performance and greatly reducing the fluctuation of on-site construction quality. Attached Figure Description

[0022] Figure 1 This is a side view of the anti-loosening power box branch connector according to an embodiment of the present invention;

[0023] Figure 2 This is a half-sectional view of the anti-loosening electrical box branch connector according to an embodiment of the present invention;

[0024] Figure 3 This is a front view of the anti-loosening power box branch connector according to an embodiment of the present invention;

[0025] Figure 4This is a flowchart of a wiring method based on an anti-loosening electrical box branch connector according to an embodiment of the present invention.

[0026] List of reference numerals in the attached drawings: 1-Welded reinforced outer shell assembly; 11-Box fixing end; 12-Connecting shaft; 121-Knurled part; 122-Observation window; 13-Branching end; 2-Laser fixing core assembly; 21-Insulating base; 211-Positioning protrusion; 22-Conductive terminal; 23-Angle angle; 3-Double anti-loosening locking assembly; 31-Locking nut; 32-Wave elastic washer; 4-Welded sealing and protection assembly; 41-Rear annular sealing groove; 42-Front annular sealing groove; 51-First through hole; 52-Second through hole. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The specific implementation methods of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1:

[0029] Please refer to the above. Figures 1 to 3 , Figure 1 This is a side view of the anti-loosening power box branch connector according to an embodiment of the present invention; Figure 2 This is a half-sectional view of the anti-loosening electrical box branch connector according to an embodiment of the present invention; Figure 3 This is a front view of the anti-loosening electrical box branch connector according to an embodiment of the present invention.

[0030] As shown in the figure, the anti-loosening power box branch connector in this embodiment adopts a composite structure design of welding reinforcement, laser fixing, double anti-loosening, and sealing protection. The components work together to achieve the core functions of anti-loosening, high sealing, and high reliability. The specific material selection, process parameter settings, and assembly relationship are as follows:

[0031] As the main structural component and external protective core of the joint, the welded reinforced outer shell assembly 1 is made of 5A06 high-strength aluminum alloy. This material has a tensile strength of not less than 310MPa and a yield strength of not less than 270MPa, combining structural strength with processing adaptability. The overall shell is designed as a three-section structure, including the fixed end 11, the connecting shaft 12, and the branch connection end 13. The three sections are integrated and sealed through inertial friction welding, eliminating the risk of leakage from gaps caused by segmented assembly. The friction welding process requires strict control of process parameters: the rotation speed is set at 2800r / min, the axial pressure is maintained at 12-15MPa, and the welding time is controlled at 8-10s. After welding, a metallurgical bonding weld (i.e., friction weld) with a width of 3-5mm is formed. The tensile strength of this weld is consistent with that of the base material, reaching over 300MPa, ensuring the integrity of the structure. After welding, the friction weld area is laser remelted using 500W power and 3mm / s scanning speed to effectively eliminate micro-defects such as porosity and slag inclusions inside the weld, and significantly improve corrosion resistance.

[0032] The three-section structure has clearly defined functions and works in concert: the fixed end 11 of the enclosure is designed as a square flange with a side length of 60mm and a thickness of 12mm. It has four symmetrically distributed mounting holes with a diameter of 8mm and a center distance of 50mm, which are adapted to M8 stainless steel bolts to fix it to the power box; the inner side of the flange is provided with a rear annular sealing groove 41. The groove has a right trapezoidal cross section with an inner wall slope of 5°, a groove width of 5mm and a groove depth of 4mm. The groove edge is laser micro-melted with 80W power and 5ms pulse width to form a smooth sealing surface with a roughness Ra≤0.8μm, providing a foundation for the subsequent assembly of sealing components. The connecting shaft 12 is 40mm long and 32mm in outer diameter. Its surface is provided with a diamond-shaped knurled part 121 with a tooth height of 0.8mm and a tooth pitch of 2mm, which can enhance the anti-slip performance during assembly and make it easier for operators to grip and tighten. A circular observation window mounting hole with a diameter of 15mm is opened in the middle section of the shaft, and a 3mm thick PC transparent material observation window 122 is inserted. The edge of the observation window 122 is fixed to the outer shell by laser sealing welding with a welding power of 60W and a pulse width of 8ms, forming a 0.8mm wide sealing weld, ensuring that the observation window 122 does not affect the viewing of the internal condition and guarantees the sealing performance. The branch connection end 13 is 25mm long and 28mm in outer diameter, with an M24×1.5 fine-pitch external thread machined on its outer circumference, achieving a thread accuracy of 6H, for use with the double anti-loosening locking component 3. The end face of the connection end has a front annular sealing groove 42, 4mm wide and 3mm deep. The bottom of the groove is fixed by laser spot welding with three evenly distributed positioning protrusions, each 1mm in diameter and 0.5mm in height, which can limit the silicone O-ring and prevent its circumferential movement. To adapt to harsh environments such as outdoor and coastal areas, the surface of the welded reinforced shell component 1 adopts a composite anti-corrosion treatment of anodizing + zinc-nickel alloy plating. First, anodizing forms an oxide film with a thickness of not less than 15μm, and then an 8-10μm zinc-nickel alloy plating layer (nickel content 12-15%) is plated. After 1000 hours of neutral salt spray testing (GB / T10125-2021), there is no red rust or plating peeling, and the salt spray resistance is improved by 40% compared with traditional nickel layers.

[0033] The welded reinforced outer shell assembly 1 has a stepped mounting through-hole inside, consisting of a first through-hole 51 and a second through-hole 52, providing a stable mounting base for the laser-fixed core assembly 2. The laser-fixed core assembly 2, as the electrical core of the connector, undertakes conductive transmission and insulation functions. It also utilizes laser welding technology to ensure no loosening is a concern. It adopts a modular design, supporting three core count specifications: 1-to-3, 1-to-4, and 1-to-5. This embodiment uses the 1-to-4 specification as an example for detailed explanation. The insulating base 21 of the core assembly is made of aluminum nitride ceramic material, which has a volume resistivity of not less than 1×10⁻⁶. 16Ω・cm, dielectric strength not less than 15kV / mm, long-term working temperature range covering -40℃~150℃, suitable for high-temperature working conditions of power systems; the base has an outer diameter of 22mm and a length of 35mm, with two symmetrically distributed positioning protrusions 211 on the outer periphery, each protrusion being 5mm wide and 2mm high, which precisely match the keyway preset on the inner wall of the second through hole 52, realizing the anti-misinsertion function and avoiding wiring failures caused by mismatch of core count.

[0034] The conductive terminal 22 is made of C1100 oxygen-free copper substrate with silver plating. The silver layer thickness is not less than 3μm, and the conductivity is not less than 98%. It is compatible with 1.5mm... 2 ~6mm 2 The cable is made of copper conductor; it has four terminals, evenly embedded inside the insulating base 21, with the core hole diameter designed to match the cable specifications, at 1.5mm. 2 Cable adapter core hole diameters: 2.0mm, 6mm 2 The cable adapter core hole has a diameter of 3.5mm, and the inner wall of the core hole is provided with spiral anti-slip texture and a pitch of 1mm, which can enhance the contact tightness with the conductor. To ensure the connection stability between the conductive terminal 22 and the insulating base 21, it is first pre-fixed by a hot melt integral molding process with a heating temperature of 280℃ and a holding time of 15s to eliminate the initial gap; then, four laser welding points (i.e., inner conductor fixing welding points) are evenly set along the outer circumference of the conductive terminal 22, with a welding point spacing of 90°, using 180W power, 0.6mm spot diameter, and 10ms pulse width to achieve metallurgical bonding between the conductive terminal 22 and the insulating base 21, completely eliminating the movement caused by vibration.

[0035] The laser-fixed core assembly 2 also includes a slanted locking angle 23, made of 1Cr18Ni9Ti stainless steel, which matches the corrosion resistance of the coating of the welded reinforced outer shell assembly 1. A total of 4 angles are set and distributed in a uniform ring array. The angle is 15° slanted, 3mm thick and 8mm high. After being embedded in the mounting groove (groove width 3.2mm and groove depth 4mm) in the inner wall of the first through hole 51, its root is metallurgically fixed to the inner wall of the outer shell by a circumferential laser weld. The weld length is 5mm. The welding speed is 250W, 0.6mm spot diameter and 2mm / s to ensure that there is no risk of the angle falling off. The engagement surface of the slanted locking angle 23 and the insulating base 21 is treated with laser micro-melting. The scanning speed is 100W and 5mm / s to form tiny anti-slip teeth (tooth height 0.2mm), which further improves the locking force after the core assembly.

[0036] To ensure reliable locking with the connector or cable joint, the branch connection end 13 is equipped with a dual anti-loosening locking component 3. This component provides multiple anti-loosening guarantees through a combination of elastic pre-tightening and laser spot welding, making it suitable for high-vibration scenarios. The locking nut 31 is made of 304 stainless steel with an internal thread of M24×1.5, precisely matching the external thread of the branch connection end 13. The nut is 18mm thick and has anti-slip teeth (0.3mm tooth height, 1mm tooth pitch) on the end face to enhance the gripping force during tightening. After the nut is tightened, two symmetrical laser anti-loosening welds are applied along the meshing surface with the external thread, with a weld spacing of 180°. A 100W power, 0.5mm spot diameter, and 8ms pulse width are used to form a mechanical stop to prevent the thread from loosening. When disassembly is required, the welds can be lightly ground with a grinding wheel without damaging the thread structure, balancing reliability and maintainability. The wave-shaped elastic washer 32 is made of stainless steel 631 with an elastic modulus of 200GPa, a thickness of 2mm, and a corrugation height of 1.5mm. It is fitted between the branch line connection end 13 and the locking nut 31. When the nut is tightened, the washer is compressed to generate an elastic preload of 2-3MPa, which continuously acts on the end face of the nut to counteract the loosening tendency caused by vibration, and forms a double anti-loosening effect with the laser anti-loosening weld. The inner wall of the second through hole 52 is provided with an annular groove (groove width 1.6mm, groove depth 2mm), in which a flexible retaining ring made of stainless steel 631 is embedded. The retaining ring has a cross-sectional diameter of 1.5mm. The edge of the mounting groove of the flexible retaining ring is laser-beveled with a bevel angle of 30° and a bevel width of 0.5mm to facilitate the insertion of the retaining ring. The open end of the retaining ring is fixed by laser spot welding with 80W power and a weld diameter of 0.4mm to prevent the retaining ring from popping out. When the insulating base 21 is installed in place, the retaining ring pops out and embeds into the positioning groove on the outer periphery of the base, forming a radial limit. Combined with the axial support of the inclined retaining angle 23, the core base is fixed both axially and radially.

[0037] The welded sealing and protection assembly 4 achieves IP67 protection (dustproof and short-term water immersion-proof) through a synergistic design of structural sealing, material sealing, and welding reinforcement, making it suitable for harsh environments such as outdoor, humid, and coastal areas. A fluororubber sealing ring, made of FKM material with a Shore hardness of 70° and a diameter of 5mm, is installed within the rear annular sealing groove 41. After assembly, the compression is 1 / 3 of the diameter (approximately 1.7mm). Fluororubber has a temperature range of -20℃ to 200℃ and excellent aging and chemical corrosion resistance, ensuring a reliable seal between the fixed end 11 of the enclosure and the mounting surface of the power box. A silicone O-ring, made of VMQ material with a Shore hardness of 60° and a diameter of 4mm, is installed within the front annular sealing groove 42. The compression is 1 / 4 of the diameter (approximately 1mm). Silicone has good elasticity and strong sealing performance. Combined with the positioning protrusions at the bottom of the groove, it prevents circumferential movement of the sealing ring, ensuring a tight seal at the branch connection end 13. All seams of the welded reinforced outer shell assembly 1, including friction welds, the mounting seam of the observation window 122, and the edge of the groove, are laser-sealed using 80W power and a 5ms pulse width to form a 0.5mm wide sealing weld, eliminating tiny gaps and preventing rainwater and moisture from entering the interior through the seams. For unused branch ports, stainless steel dust caps with M24×1.5 internal threads are installed, and a 2mm thick nitrile rubber sealing gasket is provided on the inside of the dust cap. After tightening the dust cap to the branch port 13, three uniform laser spot welds are performed along the contact area between the dust cap and the port end face, with a weld spot spacing of 120°, using 80W power, a weld spot diameter of 0.4mm, and a 6ms pulse width to form a sealing barrier to prevent dust and rainwater from entering the unused core hole.

[0038] To facilitate quality traceability and wiring operations, the connector is equipped with laser marking and a high-precision assembly control design. Laser marking is performed next to the friction weld seam to form a unique 16-character identification code containing information such as welding date, friction weld parameter number, laser weld parameter number, and batch number, enabling full lifecycle quality traceability. Simultaneously, laser marking numbers (1~4) are applied to the core hole end face of the conductive terminal 22, corresponding one-to-one with the branch circuit to avoid wiring errors. The stepped mounting through holes of the welded reinforced outer shell assembly 1 are CNC bored, with coaxiality error controlled within 0.02mm; the perpendicularity error between the flange end face of the housing fixing end 11 and the axis of the connecting shaft 12 does not exceed 0.03mm, ensuring no radial offset after installation of the laser-fixed core seat assembly 2 and smooth cable connection.

[0039] Example 2: Figure 4 This is a flowchart of a wiring method based on an anti-loosening electrical box branch connector according to an embodiment of the present invention.

[0040] The wiring method in this embodiment is precisely compatible with the above-described branch connector structure, ensuring consistent and reliable installation quality. The specific operation steps are as follows:

[0041] S1. Preparations

[0042] The first step in wiring is preparation, ensuring all components, tools, and the installation environment meet assembly requirements. Tools required include a torque wrench with a range of 0-20 N·m (accuracy ±0.5 N·m), wire crimping pliers compatible with 1.5-6 mm² copper conductors (adjustable crimping pressure), wire strippers with a stripping length of 8-10 mm, an insulation resistance meter with a range of 0-500 MΩ (accuracy ±5%), an ultrasonic flaw detector with a frequency of 2.25 MHz (10 mm probe diameter), a laser power meter with a range of 0-1000 W (accuracy ±1%), a magnifying glass with 10x magnification, alcohol wipes, a set of stainless steel M8 bolts (including flat washers and spring washers), and a grinding wheel for later solder joint removal. Materials include 1-to-4 anti-loosening electrical box connectors, 5 mm diameter fluororubber sealing rings, 4 mm diameter silicone O-rings, dust caps with nitrile rubber sealing gaskets, and 2.5 mm diameter... 2 Cold-pressed terminals for multi-strand soft conductors, and 2.5mm... 2 Copper core insulated cable (phase wire red / yellow / green, neutral wire blue, ground wire yellow-green).

[0043] During the preparation phase, each component requires rigorous inspection. Regarding the joints, visual inspection reveals no deformation or damage to the plating of the welded reinforced outer shell assembly 1, and no obvious porosity or cracks in the friction welds. Magnifying glass examination of the laser weld points (laser weld points, circumferential laser welds, and the weld sealing the observation window 122) reveals no incomplete welds or missed welds. The insulating base 21 is free of cracks, and the conductive terminals 22 are free of oxidation. The sealing rings show no signs of aging or deformation, and the dust cap gasket is intact. Regarding the cables, inspection reveals no damage to the appearance and no aging of the insulation layer. The conductor diameter (2.5mm) is measured with a micrometer. 2 The copper conductor is approximately 1.78 mm in diameter, ensuring it is compatible with the conductive terminal 22 core hole. Wipe the cable conductor, the inner wall of the core hole, and the mounting surface of the welded reinforced housing assembly 1 with an alcohol swab to thoroughly remove oil and oxide layers.

[0044] Simultaneously, the power box needs to be pre-treated. Ensure the power box is de-energized, disconnect the relevant circuit power supply, and hang a "Do Not Close" sign. Clean dust and oil from the installation location of the power box. Drill holes using an 8.5mm diameter drill bit according to the 50mm spacing of the mounting holes on the fixed end 11 of the box, and pre-embed M8 expansion nuts (15mm depth) to ensure secure installation. In addition, the laser welding equipment needs to be debugged. Pre-set the core seat reinforcement spot welding parameters (power 200W, spot diameter 0.6mm, pulse width 10ms) and the locking nut 31 anti-loosening spot welding parameters (power 100W, spot diameter 0.5mm, pulse width 8ms). Calibrate the ultrasonic flaw detector and set the detection threshold (alarm when defect diameter ≥ 0.5mm). Calibrate the torque wrench to ensure torque accuracy meets standards.

[0045] S2, Branch connector box fixing

[0046] After completing the preparations, the junction box can be fixed. This step is fundamental to ensuring the overall stability of the junction box. First, the fluororubber sealing ring is embedded into the rear annular sealing groove 41 of the fixed end 11 of the box, ensuring that the sealing ring is completely in contact with the bottom of the groove without twisting or lifting. The sealing ring is initially positioned by the cooperation of the 5° slope of the inner sidewall of the groove and the laser micro-melting surface of the groove opening.

[0047] Then, the fixed end 11 of the welded reinforced outer shell assembly 1 is attached to the mounting surface of the power box, so that the mounting hole is aligned with the pre-embedded expansion nut, and the M8 stainless steel bolt is inserted. Flat washers and spring washers are then put on in sequence. The four bolts are tightened evenly with a torque wrench at a torque of 8~10 N·m (tightening diagonally alternately) to ensure that the flange is tightly attached to the mounting surface and the compression of the sealing ring reaches about 1.7 mm.

[0048] After the enclosure is fixed, an ultrasonic flaw detector must be used to conduct a comprehensive inspection of the friction weld. The probe moves around the weld circumferentially (moving speed 5mm / s), focusing on the weld area between the fixed end 11 of the enclosure and the connecting shaft 12, and between the connecting shaft 12 and the branch line docking end 13, to ensure that there are no defects such as internal porosity, cracks, or slag inclusions (the test results show that the defect diameter is <0.5mm, which is considered qualified). If unqualified defects are detected, the joint must be replaced and reinstalled.

[0049] S3, Modular Core Assembly

[0050] After the junction box is fixed, the modular core seat is assembled. This step requires precise matching of the core seat specifications according to the junction requirements and ensuring a secure installation. According to the junction requirement of 1 to 4 in this embodiment, select the laser-fixed core seat assembly 2 with the corresponding number of cores, and check whether the positioning protrusion 211 of the insulating base 21 matches the keyway on the inner wall of the second through hole 52 to ensure that the anti-misinsertion function is effective. Hold the laser-fixed core seat assembly 2 and slowly insert it along the guide chamfer at the front end of the first through hole 51 (2mm beyond the end face of the junction end 13) until the insulating base 21 fits against the stepped surface of the mounting through hole (the junction of the first through hole 51 and the second through hole 52). At this time, the elastic retaining ring pops out and embeds into the positioning groove of the insulating base 21, and a "click" sound can be heard. Confirm that the core seat is installed in place through the observation window 122 of the connecting shaft part 12 (the end face of the core seat is flush with the stepped surface, and there is no axial movement).

[0051] For environments with strong vibrations, such as industrial workshops, the core seat needs to be reinforced by laser spot welding. The laser welding fixture is fixed to the outside of the welded and reinforced outer shell assembly 1. The laser head is adjusted to align with the contact point between the core seat and the end face of the through hole. Four even spot welds are performed along the circumference (at a spacing of 90°). The spot welding parameters are: power 150-250W (200W is used in this embodiment), spot diameter 0.6mm, and pulse width 10ms. After welding, the weld points are observed with a magnifying glass to ensure that there are no incomplete welds or missing welds and that the core seat is not loose.

[0052] S4, Incoming and Outgoing Line Connections

[0053] After the core socket is assembled, the incoming and branch wire connection process begins. This step directly affects the electrical transmission performance of the connector and must be strictly followed. First, use wire strippers to remove the insulation layer of the incoming and branch wires, setting the stripping length to 9mm (compatible with the 22 conductive terminal length). Avoid damaging the conductor during the stripping process (no broken wires, no burrs). For multi-strand flexible conductor cables, first twist the conductors neatly and then crimp the cold-pressed terminals (crimping pressure 35MPa, crimped terminal outer diameter 2.8mm, compatible with the core hole).

[0054] Identify the inlet core hole marked "IN" (or number "0") on the laser fixing core assembly 2, insert the inlet conductor (or the conductor after crimping the cold-pressed terminal) into the core hole, with an insertion depth of not less than 6mm (confirmed through observation window 122); use wire crimping pliers to press the core hole 2~3mm outside, with a pressing pressure of 35MPa, so that the spiral anti-slip texture on the inner wall of the core hole is tightly engaged with the conductor; after pressing, pull the cable by hand to confirm that there is no looseness (no displacement when the pulling force is ≥50N).

[0055] According to the wiring diagram, insert the three branch conductors into the corresponding core holes numbered "1", "2", and "3" respectively, and repeat the insertion, pressing, and pulling verification steps for the incoming line connection. During the wiring process, strictly follow the color specification: the phase wire (red / yellow / green) corresponds to branch wires 1 to 3, the neutral wire (blue) has a spare core hole reserved (if any), and the ground wire (yellow-green) is connected to the grounding busbar of the power box (the core seat of this connector can reserve a grounding terminal, which can be configured according to requirements); ensure that there are no incorrectly connected circuits and no exposed conductors.

[0056] S5. Anti-loosening locking and sealing

[0057] After wiring is completed, anti-loosening locking and sealing operations are performed to further enhance the anti-loosening performance and sealing protection effect of the connector. First, the silicone O-ring is embedded into the front annular sealing groove 42 of the branch terminal 13, and the three positioning protrusions at the bottom of the groove are used to limit the circumferential movement of the sealing ring.

[0058] Subsequently, a waveform elastic washer 32 is sleeved on the wire splitting and docking end 13, and a locking nut 31 is screwed on. Tighten it with a torque wrench according to a torque of 6 - 8 N·m to ensure that the waveform elastic washer 32 generates an elastic pre-tightening force of 2 - 3 MPa; for a strong vibration scenario, start the laser welding equipment and perform 2-point symmetric laser anti-loosening solder joints (with a spacing of 180°) along the meshing surface of the locking nut 31 and the external thread. The spot welding parameters are a power of 80 - 120 W (100 W is selected in this embodiment), a spot diameter of 0.5 mm, and a pulse width of 8 ms; after welding, clean the welding slag and turn the locking nut 31 by hand to confirm that there is no looseness.

[0059] This embodiment is of the 1-to-4 specification and has no idle ports; if it is of the 1-to-5 specification, it is necessary to protect the idle 1 port: screw the dust cap tightly onto the wire splitting and docking end 13 to ensure that the inner sealing gasket is pressed tightly, and then perform at least 2-point laser spot welding sealing along the joint surface of the dust cap and the docking end face. The spot welding parameters are a power of 80 W, a spot diameter of 0.4 mm, and a pulse width of 6 ms to complete the sealing.

[0060] S6. Detection and verification

[0061] After the anti-loosening locking and sealing operations are completed, a series of detections and verifications are required to ensure that the performance of the joint meets the standards. First, perform a sealing performance test. Use an airtightness detector to test the sealing performance of the entire joint. The test pressure is 0.3 MPa, and the pressure is maintained for 30 s. The qualified leakage rate is ≤0.01 MPa / s; focus on detecting the sealed welding area of the observation window 122, the front annular sealing groove 42, the rear annular sealing groove 41, and the laser sealing and welding repair area to ensure that there is no gas leakage.

[0062] After the sealing performance test is qualified, carry out an insulation performance test. Use a 500 V insulation resistance meter to measure the insulation resistance between each wire splitting, between the wire splitting and the welded and strengthened housing assembly 1. The measurement time is 1 min, and the qualified insulation resistance value is ≥10 MΩ; if the insulation resistance does not meet the standard, it is necessary to check for damage to the cable insulation layer, contamination of the core seat, or short circuit of the laser solder joints, and re-test after rectification.

[0063] After passing the insulation performance test, remove the "Do not close the switch" sign, close the power supply of the relevant circuit, and use a multimeter (DC voltage range) to measure the on-off status of each wire splitting. Confirm that the incoming line and the wire splitting 1 - 3 are well-conducted (voltage drop ≤0.1 V), and there is no open circuit or short circuit phenomenon; observe that the relevant equipment in the power distribution box is operating normally, without abnormal heating or abnormal noise.

[0064] Subsequently, conduct a re-inspection of the welding quality. Observe all laser solder joints (laser solder joints, circumferential laser welds, laser anti-loosening solder joints, dust cap sealing solder joints) with a 10-fold magnifying glass to confirm that there are no air holes, cracks, or false welds; read the parameter log of the welding equipment through a laser power meter to trace the actual power, pulse width and other parameters of each solder joint to ensure that they are consistent with the preset standards.

[0065] Finally, the anti-loosening verification was carried out by using a vibration table to simulate vibration test (frequency 10~50Hz, amplitude 0.5mm, duration 30min). After the test, the joint was checked and found to be loose, the laser fixing core seat assembly 2 was not moved, the solder joints were not detached, and the cable was pulled without displacement. The torque of the locking nut 31 and the flange bolt was checked again with a torque wrench and there was no obvious attenuation (torque loss ≤10%).

[0066] S7. Finishing touches

[0067] After all inspection items pass, the final stage begins. The cables inside the power box are organized and secured neatly with nylon cable ties at 150mm intervals to prevent cable pulling on the joints; tools, welding slag, and debris are removed from the installation site to ensure no foreign objects remain inside the power box.

[0068] Record the wiring information in detail, including the specifications of the branch connector (1 to 4), the number of cores, the wiring circuit number (incoming line - branch line 1~3), the welding parameters (core seat reinforcement spot welding 200W, locking nut anti-loosening spot welding 100W), the test data (insulation resistance 150MΩ, leakage 0.005MPa / s), and the unique identification code (such as 20240520-F2800-P100-B001), and archive it for future reference.

[0069] For outdoor electrical boxes, a stainless steel protective cover (2mm thick, 120×80×60mm in size) can be installed on the outside of the connector. The protective cover is fixed to the electrical box with bolts to further improve its impact resistance and corrosion resistance.

[0070] The anti-loosening power box branch connector and wiring operation method of this embodiment have been tested and show excellent performance in various indicators: In terms of anti-loosening performance, after a vibration test of 10~50Hz, amplitude 0.5mm, and continuous for 100h, the connector did not loosen, and the change in contact resistance of conductive terminal 22 was ≤0.01Ω, which is far superior to traditional connectors (the change in contact resistance after 20h vibration is ≥0.1Ω); In terms of sealing performance, after the IP67 protection level test (immersion in water for 1m for 30min), there was no water ingress or condensation inside, and the insulation resistance did not decrease; In terms of corrosion resistance, after a neutral salt spray test for 1000h, the plating of the welded reinforced outer shell component 1 showed no red rust, the friction weld showed no corrosion, and the sealing performance remained good; In terms of electrical performance, under the conditions of rated voltage 10kV and rated current 30A, after continuous operation for 72h, the connector temperature rise was ≤30K, and there was no abnormal heating; In terms of operation efficiency, the time for skilled operators to complete the wiring installation (including testing) according to this method is ≤40min, which is 30% more efficient than the traditional branch connector installation.

[0071] In summary, this embodiment fully achieves the technical goals of the present invention—anti-loosening, high sealing, high reliability, and easy maintenance—through precise material selection, strict process parameter control, and standardized operating procedures. It is applicable to various scenarios such as outdoor power boxes, industrial workshop power boxes, and communication base station power cabinets, and has broad application value.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A type of anti-loosening electrical box branch connector, characterized in that, include: The welded reinforced outer shell assembly is a sealed shell formed by integrally connecting segmented structures through friction welding. A laser-fixed core assembly is disposed within the welded reinforced outer shell assembly, including an insulating base and conductive terminals embedded in the insulating base. The conductive terminals and the insulating base, as well as the insulating base and the welded reinforced outer shell assembly, are fixedly connected by a laser welding process. A dual anti-loosening locking assembly is provided at the branching and mating end of the welded reinforced shell assembly to achieve mechanical locking with the mating connector; A weld sealing and protection assembly, including a sealing groove and a sealing ring disposed on a weld-strengthened housing assembly.

2. The anti-loosening electrical box branch connector according to claim 1, characterized in that, The welded reinforced outer shell assembly includes a housing fixed end, a connecting shaft, and a branch line docking end, all integrally connected by inertial friction welding. The surface of the welded reinforced outer shell assembly is coated with an anti-corrosion coating, and the friction weld area is treated with laser remelting. The joint is reinforced by laser sealing welding. The inner wall of the welded reinforced outer shell assembly is provided with a keyway. The housing fixed end is a flange structure with mounting holes. The outer periphery of the branch line docking end is provided with external threads. The area on the connecting shaft corresponding to the installation position of the insulating base is provided with a transparent observation window, and the edge of the observation window is sealed to the connecting shaft by laser sealing welding.

3. The anti-loosening electrical box branch connector according to claim 2, characterized in that, The insulating base is made of aluminum nitride ceramic, and its outer wall is provided with positioning protrusions that are adapted to the keyways on the inner wall of the welded and reinforced outer shell assembly; after the conductive terminal is pre-fixed by hot melting, it is reinforced by welding to the insulating base through at least one laser welding point on its outer periphery.

4. The anti-loosening electrical box branch connector according to claim 3, characterized in that, The inner wall of the welded reinforced outer shell assembly is also provided with an installation groove; the laser fixing core assembly also includes an angled retainer; after the angled retainer is embedded in the installation groove, the root of the angled retainer is fixedly connected to the inner wall of the welded reinforced outer shell assembly through a circumferential laser weld.

5. The anti-loosening electrical box branch connector according to claim 4, characterized in that, The dual anti-loosening locking assembly includes a locking nut that mates with the external thread of the branch line connection end, and a wave-shaped elastic washer disposed between the locking nut and the end face of the connector; at least one laser anti-loosening weld point is provided at the meshing surface of the locking nut and the external thread of the branch line connection end.

6. The anti-loosening electrical box branch connector according to claim 5, characterized in that, The sealing groove includes a front annular sealing groove and a rear annular sealing groove located at both ends, and the groove edges of the sealing groove are laser micro-melting treated to form a smooth sealing surface.

7. A wiring method based on the anti-loosening junction box connector as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation: Inspect connectors and cables, and pre-treat the mounting surface; S2. Fix the junction box of the branch connector to the power box using a flange, and perform non-destructive testing on the friction weld area; S3. Select the laser fixing core seat assembly with the corresponding number of cores according to the branch requirements, and insert it into the mounting through hole of the welded reinforced shell assembly until it is locked in place. Laser spot welding is performed to reinforce the joint between the laser fixing core seat assembly and the welded reinforced shell assembly; S4. Insert the incoming conductor and the branch conductor into the conductive terminals of the laser fixing core seat assembly respectively and press them firmly; S5. Install the sealing ring and double anti-loosening locking assembly at the branch connection end, and tighten them to the preset torque. Laser anti-loosening spot welding is performed on the locking nut. S6. Perform sealing tests, insulation performance tests, and welding quality re-inspections on the assembled branch connectors.

8. The wiring method for an anti-loosening electrical box branch connector according to claim 7, characterized in that, The laser spot welding reinforcement parameters in step S3 are: power 150-250W, and at least 3 uniform spot welds are performed along the joint between the core seat and the outer shell; the laser anti-loosening spot welding parameters in step S5 are: power 80-120W, and at least 2 symmetrical spot welds are performed on the locking nut and the thread meshing surface.

9. The wiring method for an anti-loosening electrical box branch connector according to claim 8, characterized in that, The non-destructive testing in step S2 uses an ultrasonic flaw detector with a detection frequency of 2.0-2.5MHz; the welding quality re-inspection in step S6 includes using a magnifying glass to check the integrity of all laser welds and using a laser power meter to trace the welding parameters.

10. The wiring method for an anti-loosening electrical box branch connector according to claim 9, characterized in that, Also includes: Step S7: For unused branch ports, tighten the dust cap with sealing gasket and perform laser spot welding at least 2 points along the contact area between the dust cap and the end face of the port.

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