Wire bar, wiring terminal structure and power distribution cabinet

Abstract

The invention discloses a wire row, a wiring terminal structure and a power distribution cabinet. A microcapsule A is arranged in an insulating coating of a wire bar, and a microcapsule B is arranged in a connecting area of a wiring terminal. When the two are crimped, pressure enables the microcapsule to be broken, different released capsule core materials are mixed with each other to generate chemical reaction, liquid metal is generated, low-temperature welding is achieved, and therefore reliable electric connection is completed. In addition, by means of the wedge-shaped protrusion-groove structural design, the breaking time sequence of the microcapsules and discharging of reaction waste liquid are accurately controlled, and intelligence and high reliability of the connecting process are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution cabinet preparation, in particular to a wire bar, a wiring terminal structure and a power distribution cabinet. BACKGROUND

[0002] In the field of electrical engineering, the electrical connection between the wire bar and the wiring terminal is one of the most basic and core connection links in power distribution systems, control systems and various electrical equipment. The reliability of the connection is directly related to the energy consumption, temperature rise, stability and even personal safety of the entire system.

[0003] Currently, the existing technical solution in this field mainly relies on mechanical connection principles. Specifically, the connection point area of the wire bar is treated with silver or tin plating to reduce contact resistance and resist oxidation, and then the wire is clamped by the screw pressure of the wiring terminal or the elastic pressure of the spring sheet to generate contact. Although this technical route is widely used, its inherent physical properties determine that it has a series of long-term problems that cannot be completely solved:

[0004] Contact resistance instability and energy consumption problem: Mechanical contact relies on the limited surface protrusions of the contact point for conduction, and the actual conduction area is much smaller than the theoretical contact area, resulting in high contact resistance. At the same time, according to Joule's law (Q = I2Rt), when a large current passes through, the resistance will generate significant Joule heat, causing the connection point to overheat. This not only causes continuous energy waste, but also poses a hidden danger to the safe operation of the system.

[0005] Long-term reliability and service life problem: Mechanical connection points are inherently dynamic and unstable. Their stability is challenged by a variety of factors: material creep and stress relaxation: under the action of long-term operation and thermal cycling, the screw clamping force or spring pressure will gradually decrease, causing the contact pressure to decrease, the contact resistance to further increase, and a vicious cycle to form; fretting wear and oxidation: vibrations during equipment operation can cause relative motion of the contact surface, wear the plated layer on the surface, expose the base metal and cause oxidation, resulting in a non-conductive oxide film that dramatically increases the contact resistance; environmental corrosion: in harsh environments such as humidity and salt spray, the connection point is easily corroded, and the electrical conductivity deteriorates sharply.

[0006] Complexity of installation and maintenance and consistency problem: The reliability of traditional connections is highly dependent on the skills and responsibility of the installation personnel. During installation, strict process procedures must be followed, such as cleaning the contact surface, applying conductive paste, and tightening the screw with a torque wrench according to the standard torque. Any oversight at any stage can leave a hidden fault for long-term operation.

[0007] In view of the above, the present application proposes to introduce a "wedge-shaped protrusion-groove" mechanical structure and a "cleaning-welding" microcapsule chemical system to achieve a paradigm shift in electrical connection technology. SUMMARY

[0008] To solve the above technical problems, the present application provides a wire bar, a terminal structure and a power distribution cabinet. In the technical scheme of the present application, the wire bar comprises a conductive base and an insulating layer covering the surface of the conductive base, wherein,

[0009] The insulating layer is uniformly dispersed with microcapsules A;

[0010] The core of the microcapsules A contains a reducing agent;

[0011] The conductive base further comprises a connecting area on the front end face, and the outer wall of the connecting area is provided with an array of wedge-shaped protrusions.

[0012] Further, in the technical scheme of the present application, the reducing agent is specifically 60 wt% ultra-fine zinc powder, 20 wt% nano-zinc oxide and 20 wt% nano-sheet-shaped boehmite.

[0013] Further, in the technical scheme of the present application, the microcapsules A have a core-shell middle-shell structure, the inner wall material of which is mesoporous silica, and the outer wall material of which is dense silica.

[0014] Further, in the technical scheme of the present application, the thickness of the mesoporous silica layer is 20-30 nm, and the thickness of the dense silica layer is 80-100 nm.

[0015] A terminal structure comprises a terminal conductor and an insulating shell, and the terminal conductor is provided with a connecting area for pressing connection with the wire bar, and the connecting area is provided with an array of wedge-shaped grooves matched with the wedge-shaped protrusions.

[0016] The inner wall of the wedge-shaped grooves is attached with microcapsules B;

[0017] The core of the microcapsules B contains a low-melting solder oxide composite powder;

[0018] When the terminal is pressed against the wire bar, the engagement pressure of the wedge-shaped protrusions and the wedge-shaped grooves causes the microcapsules A and the microcapsules B to break in sequence, and the released reducing agent and the low-melting solder oxide composite powder are mixed to realize electrical connection through a solid-state displacement reaction.

[0019] Further, in the technical scheme of the present application, the low-melting solder oxide composite powder comprises, by mass percentage, 98%-99% of a mixture of bismuth oxide and tin oxide, and 1%-2% of sodium fluoride or fluoroborate.

[0020] Further, in the technical scheme of the present application, the molar ratio of bismuth oxide to tin oxide is 42:58.

[0021] Further, in the technical scheme of the present application, the wedge-shaped grooves and the wedge-shaped protrusions form a height interference fit in height, and a width gap fit in width.

[0022] A power distribution cabinet includes a cabinet body, a busbar is provided inside the cabinet body, and the aforementioned busbar and terminals are installed inside the cabinet body.

[0023] Specifically, several sets of terminals are arranged in parallel and electrically connected to the busbar through a wedge-shaped groove array and a wedge-shaped protrusion array; the rear end face of the busbar is electrically connected to the busbar.

[0024] A method for electrically connecting a busbar and a terminal block, applied to the aforementioned busbar and terminal block, includes the following steps:

[0025] Alignment steps: Align the connection area of ​​the terminal block with the connection part of the cable strip;

[0026] Crimping step: Apply pressure to the terminal block to crimp it to the wire bar;

[0027] Reaction steps: During the pressing process, the pressure causes microcapsules A and B to rupture, and the released reducing mixture mixes with the low-melting-point solder oxide composite powder to undergo a solid displacement reaction;

[0028] The applied pressure is 10-15 kN;

[0029] Connection steps: The liquid metal generated by the reaction wets and connects the surfaces of both metals, forming a metallurgical bond and achieving electrical conductivity.

[0030] Effective gain:

[0031] In the technical solution of this invention, a paradigm shift in electrical connection technology is achieved by introducing a "wedge-shaped protrusion-groove" mechanical structure and a "cleaning-welding" microcapsule chemical system. First, through the high shear force and precise triggering provided by the "wedge-shaped protrusion-groove" structure, microcapsule B ruptures preferentially, followed by pressure-triggered rupture of microcapsule A. The Zn mixed powder and the low-melting-point solder oxide composite powder undergo a solid-state displacement reaction to generate a low-temperature eutectic liquid phase. The energy released by the reaction cleans the metal surface, while the liquid metal wets the clean metal surface, forming an atomic-level metallurgical weld, thus improving the stability of the mounting point.

[0032] Moreover, by incorporating complex processes into microcapsules and mechanical structures, the results are guaranteed by the materials and structures themselves. During installation, only the installation pressure needs to be controlled to achieve consistent installation. At the same time, the process is simplified from "cleaning - applying paste - tightening - verification" to "alignment - pressing" in one step, improving installation efficiency.

[0033] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0034] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the connection state between the cable tray and the terminal block of the present invention;

[0036] Figure 2 This is a schematic diagram of the connection structure between the cable tray and the terminal block of the present invention;

[0037] Figure 3 This is a schematic diagram of the cross-sectional structure of the wire connection area of ​​the present invention;

[0038] Figure 4 This is a schematic diagram of the rear end face structure of the wire rack of the present invention;

[0039] Figure 5 This is a schematic diagram of the rear end face structure of the terminal block of the present invention;

[0040] Figure 6 This is a flowchart illustrating the fabrication and assembly process of the busbar of the present invention.

[0041] The components include: 1. Busbar, 11. Conductive substrate, 12. Insulating layer, 13. Wedge-shaped protrusion, 2. Terminal block, and 21. Wedge-shaped groove. Detailed Implementation

[0042] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] One aspect of the present invention is a wire bar 1, which includes a conductive substrate 11, an insulating layer 12 wrapped around the outer wall of the conductive substrate 11, and a number of connection areas are spaced apart on the outside of the conductive substrate 11. A number of wedge-shaped protrusions 13 are fixedly connected to the upper end face of the connection areas.

[0044] Please see Figure 3 The wedge-shaped protrusion 13 has a height of 0.5±0.02mm, a width of 2±0.05mm, a length of 8.00±0.10mm, and a tilt angle of 10±0.5°. The array specifications are: array center distance x=4±0.05mm, y=3±0.05mm, and the number of arrays is 3*3.

[0045] It should be added that the top and bottom edges of the wedge-shaped protrusion 13 are chamfered, with a top fillet radius of 0.05 mm and a root fillet radius of 0.10 mm.

[0046] Specifically, the conductive substrate 11 is made of high-purity T2 copper with a Cu purity of ≥99.9%.

[0047] The specific materials of insulation layer 12, by volume percentage, include:

[0048] Modified epoxy resin system (EP) 40-50 vol%

[0049] Boron nitride nanosheets (BN) 25-30 vol%

[0050] Microcapsule A 10-15 vol%

[0051] Dispersant 1-1.5 vol%

[0052] Defoamer 0.5-1 vol%

[0053] Hardener 3-3.5 vol%

[0054] Specifically, the dispersant is a high molecular weight block copolymer solution. In this embodiment, the dispersant is selected from BYK-Chemie GmbH, model BYK-110. The defoamer is an organosilicon defoamer. In this embodiment, the defoamer is selected from BYK-Chemie GmbH, model BYK-066. The curing agent is a modified amine curing agent, specifically a polyamide curing agent, an amide-based amine curing agent, and a cyclic aliphatic amine adduct.

[0055] The insulating layer 12 is coated and cured onto the outer wall of the conductive substrate 11. The insulating layer 12 has a thickness of 150±10μm and a surface resistivity ≥ 1×10⁻⁶. 14 Ω·m, insulation strength ≥25 kV / mm, thermal conductivity ≥1.8 W / (m·K).

[0056] Furthermore, microcapsule A has a particle size of 50-80 μm and comprises, by mass percentage, 60 wt% core material and 40 wt% wall material.

[0057] Specifically, core materials include:

[0058] Ultrafine zinc powder (Zn) 60 wt%

[0059] Nano zinc oxide (ZnO) 20 wt%

[0060] Nanosheet boehmite (γ-AlOOH) 20 wt%;

[0061] The wall material consists of a mesoporous silica inner layer and a dense silica outer layer.

[0062] The ultrafine zinc powder, with a diameter of 1 μm, is sourced from Jiangsu Boyun Nanotechnology Co., Ltd.; the nano zinc oxide, with a diameter of 50 nm, is sourced from American Chemical Industries, model US3560; and the γ-AlOOH is sourced from Hefei Zhonghang Nanotechnology Co., Ltd., model γ-AlOOH-50. The mesoporous silica has an inner pore size of 2 nm, an inner layer thickness of 20-30 nm, and an outer layer thickness of 80-100 nm.

[0063] The fabrication process of the busbar 1 includes the following steps:

[0064] Cut the copper strip to the required length, and use a five-axis precision CNC milling machine to machine several sets of wedge-shaped protrusion arrays at the mounting points of the terminals and the connection points of the busbars; ultrasonically clean in a 60°C NaOH solution for 5 minutes, rinse with clean water, then soak in 10% dilute sulfuric acid for 30 seconds to remove the oxide layer, rinse with deionized water, and blow dry with a high-pressure air gun;

[0065] Ultrafine zinc powder, nano zinc oxide, and nano boehmite are added to a three-dimensional mixer in proportion and mixed for 4 hours until homogeneous to obtain a mixed core material.

[0066] The sol-gel method was employed, using hexadecyltrimethylammonium bromide (CTAB) as a template agent and tetraethyl orthosilicate (TEOS) as the silicon source. The mixed core material was dispersed in an ethanol / water solution, and CTAB and ammonia were slowly added. TEOS was added dropwise while stirring, and the reaction was carried out for 6 hours. The product was collected by centrifugation, washed, and dried at 60°C to obtain mesoporous SiO2-coated microspheres.

[0067] Microspheres were placed in a reactor using chemical vapor deposition (CVD), and SiCl4 and H2O vapors were introduced. The reaction was carried out at 400°C, and a dense, non-porous SiO2 layer was deposited on the surface. Microcapsules A with a diameter of 50-80 μm were obtained by sieving.

[0068] EP, BN filler, solvent, and additives were added to a high-speed disperser in proportion and dispersed at 2000 rpm for 30 minutes. The mixture was then transferred to a vertical ball mill and ground for 4 hours until the fineness was ≤25μm. The mixture was then transferred to a low-speed mixing tank, and microcapsule A was slowly added and stirred at 500 rpm for 30 minutes. The slurry was then transferred to a vacuum degassing machine and degassed at -0.095 MPa for 15 minutes to obtain the coating.

[0069] Secure the copper strip to the automatic spraying line. Use a high-pressure airless spraying system with a nozzle diameter of 1.2mm, a pressure of 0.5MPa, and a moving speed of 0.5m / s to spray evenly and allow it to level for 15 minutes.

[0070] The product is placed in a temperature-controlled oven for step curing: 80℃ for 1 hour, then heated to 120℃ and kept constant for 2 hours, followed by natural cooling to room temperature to obtain line 3.

[0071] Understandably, microcapsule A, as a functional filler, enhances the mechanical strength and thermal conductivity of the insulating coating. Under normal operating conditions, the core material slowly leaks out, and the leaked zinc powder and other metal powders react with O2, H2O, and Cl- that have entered the environment. - The reaction prevents oxidation of the copper substrate of the busbar and repairs microscopic defects in the insulation layer.

[0072] In another aspect, the present invention provides a terminal block 2 that is connected to the above-mentioned busbar, including a connection area that is electrically connected to the connection area, and a plurality of wedge-shaped grooves 21 are arrayed on the side of the connection area near the mounting point on the front end face of the busbar.

[0073] Please see Figure 4 The wedge-shaped groove 21 has a groove depth of 0.45 + 0.00 / - 0.02 mm, a groove width of 2.10 + 0.05 / - 0.00 mm, a groove inclination angle of 10 ± 0.5°, and a groove length of 8.20 ± 0.10 mm. The array specifications are completely consistent with those of the wedge-shaped protrusion 13. The inner wall of the wedge-shaped groove 21 is coated with an anti-oxidation layer with a thickness of 0.10 ± 0.02 mm. The anti-oxidation layer is attached to the inner wall of the wedge-shaped groove 21 by screen printing and curing. Microcapsules B are distributed in the anti-oxidation layer.

[0074] Specifically, the wall material of microcapsule B is a gelatin-gum arabic composite wall, which facilitates rupture under pressure. The core material is a low-melting-point solder oxide composite powder, accounting for 60% to 70% of the total capsule mass. The particle size of microcapsule B is 1-3 μm, much smaller than that of the core material of microcapsule A, in order to increase the reaction contact area.

[0075] Specifically, the low-melting-point solder oxide composite powder comprises, by mass percentage: 98%–99% of a mixture of bismuth oxide (Bi₂O₃) and tin oxide (SnO₂), and 1%–2% of sodium fluoride (NaF) or fluoroborate. NaF or fluoroborate acts as a flux, helping to lower the reaction activation energy and improve solder flowability.

[0076] The molar ratio of Bi2O3 to SnO2 is 42:58.

[0077] The preparation process of microcapsule B includes:

[0078] Bi2O3, SnO2 and NaF or fluoroborate powder were ball-milled and mixed for 4 hours and then passed through a 400-mesh sieve; gelatin and gum arabic were dissolved separately in water at 60°C to prepare 3% solutions.

[0079] The core material powder was dispersed in a gelatin solution, and a gum arabic solution was slowly added while adjusting the pH to 4.0-4.5, causing the two colloids with opposite charges to aggregate and encapsulate on the core material surface. The mixture was cooled to below 10°C, and glutaraldehyde was added to crosslink and cure the wall material. The mixture was then centrifuged and washed to remove residual reagents. Spray drying was performed, and the powder was collected and sieved to separate 1-3 μm microcapsules (B).

[0080] The anti-oxidation coating process includes:

[0081] Add potassium silicate inorganic glue, deionized water, dispersant and defoamer to a mixing vessel at a mass ratio of 20-25, 10-15, 0.5-1, 0.2-0.5 and mix at low speed. Then slowly add 60-65 parts by mass of microcapsule B and stir at <300 rpm for 30 minutes. Defoam under vacuum.

[0082] Using a 200-mesh stainless steel wire mesh, the screen is laser-etched according to the groove pattern, and the connecting area is fixed to the printing fixture with the groove facing upward. The automatic printing machine scrapes the coating twice to ensure that the paste fully fills the groove.

[0083] The material is transferred to a curing oven with a heating rate of <2℃ / min. It is first cured at 60℃ for 30 minutes for initial curing, and then cured at 120℃ for 60 minutes for secondary curing to obtain the wiring terminals.

[0084] Understandably, during installation, when the power terminal is pressed down, the inclined surface of the wedge-shaped protrusion 13 contacts the inclined surface of the wedge-shaped groove 21. Due to the interference fit, before the top of the wedge-shaped protrusion 13 contacts the bottom of the wedge-shaped groove 21, the microcapsules B on the sidewall of the wedge-shaped groove 21 are subjected to enormous shear force and rupture first. The low-melting-point solder oxide composite powder is released and distributed in the gap. As the pressure increases, the top of the wedge-shaped protrusion 13 contacts the bottom of the wedge-shaped groove 21, and the microcapsules A at the wedge-shaped protrusion 13 are crushed, releasing zinc powder and other mixed metal powders as reducing agents, which mix with the existing low-melting-point solder oxide composite powder in the lateral gap. Under enormous pressure and ambient temperature, the mixed powder undergoes a solid-state displacement reaction. The resulting liquid bismuth-tin solder wets the metal surfaces on both sides, forming a metallurgical bond; insulating byproducts are squeezed out through the gap, achieving instantaneous low-temperature welding and conductivity. The specific reaction formula is as follows:

[0085] 3Bi2O3 + 2Zn → 6Bi + 2ZnO + Heat;

[0086] 2SnO2 + 2Zn → 2Sn + 2ZnO + Heat;

[0087] Furthermore, the generated metallic bismuth and tin nanoparticles melt instantaneously under the heat released by the reaction and external pressure to form a liquid eutectic phase, which wets the metal surface of the busbar and terminals, achieving low-temperature welding; the generated zinc oxide is an insulator, which is squeezed out of the connection interface under subsequent pressure, or exists at the edge of the weld, without affecting conductivity.

[0088] The present invention also proposes a power distribution cabinet, including a cabinet body, a busbar and several sets of DIN rails installed inside the cabinet body, and the aforementioned busbar and several sets of terminal blocks installed inside the cabinet body.

[0089] Specifically, several sets of terminals are mounted side-by-side on a DIN rail and electrically connected to the busbar; the wedge-shaped grooves 21 array and the wedge-shaped protrusions 13 array of terminals 2 are arranged vertically in correspondence.

[0090] Several sets of terminals are sequentially installed at the mounting points on the front end of the busbar. Pressure is applied to the terminals to make them crimped to the busbar. The installed terminals and busbar are then crimped to the busbar through the connection points on the rear end of the busbar by applying pressure.

[0091] It should be noted that the area where the busbars connect to each other is provided with a corresponding array of wedge-shaped grooves, and the inner wall of the wedge-shaped grooves is coated with an anti-oxidation layer, in which microcapsules B are distributed.

[0092] In other embodiments, a low-temperature welding material is placed in the inlet hole at the lower end of the terminal block, and the mounting points at both ends of the busbar correspond to the connection points at the rear end of the busbar. When installing the terminals at both ends, pressure is applied to the terminals at both ends to promote welding of the low-temperature welding material to the wires. At the same time, the connection areas between the mounting points of the busbar and the terminals, as well as the connection points between the busbar and the busbar, are achieved by crimping to realize low-temperature solid-state welding, thus simultaneously realizing electrical connection and installation.

[0093] A method for electrically connecting a busbar and a terminal block, characterized in that it is applied to the busbar 1 and the terminal block 2, and includes the following steps:

[0094] Alignment steps: Align the connection areas of several sets of terminals with the mounting positions of the cable trays in sequence;

[0095] Crimping step: Apply pressure to the terminal block to crimp it to the wire bar;

[0096] Reaction steps: During the pressing process, the pressure causes microcapsules A and B to rupture, and the released reducing mixture mixes with the low-melting-point solder oxide composite powder to undergo a solid displacement reaction;

[0097] Connection steps: The liquid metal generated by the reaction wets and connects the surfaces of both metals, forming a metallurgical bond and achieving electrical conductivity.

[0098] Specifically, initially apply pressure slowly to 3 kN and hold for 1-2 seconds to ensure microcapsule B ruptures and completes the cleaning reaction; continue to apply pressure steadily to the target pressure value of 10-15 kN and hold for 1-2 seconds to ensure microcapsule A ruptures and completes the welding; slowly release the pressure to complete the crimping.

[0099] Understandably, the wire is placed in the inlet hole at the lower end of the terminal block, and the wedge-shaped groove array of the terminal block's connection area corresponds to the wedge-shaped protrusion array of the cable busbar's installation location. While applying pressure to fix the wire in the inlet hole, the terminal block and cable busbar are crimped together to achieve electrical connection. After several sets of terminal blocks are sequentially fixed to the front end face of the cable busbar to complete the installation, the wedge-shaped protrusion array on the rear end face of the cable busbar corresponds to the wedge-shaped groove array at the connection point of the busbar. Electrical connection with the busbar is achieved through crimping. The cable busbar is then installed in the distribution cabinet.

[0100] To further understand the present invention, the following description, in conjunction with embodiments, illustrates a terminal block structure provided by the present invention. The scope of protection of the present invention is not limited by the following embodiments.

[0101] Example 1

[0102] Preparation of microcapsule A:

[0103] Ultrafine zinc powder, nano zinc oxide, and nano boehmite were added to a three-dimensional mixer in a mass ratio of 6:2:3 and mixed for 4 hours until homogeneous to obtain a mixed core material.

[0104] The mixed core material was dispersed in an ethanol / water solution, CTAB and ammonia were slowly added, TEOS was added dropwise with stirring, the reaction was carried out for 6 hours, the product was collected by centrifugation, washed, and dried at 60°C to obtain mesoporous SiO2-coated microspheres.

[0105] Microspheres were placed in a reactor using chemical vapor deposition (CVD), and SiCl4 and H2O vapors were introduced. The reaction was carried out at 400°C, and a dense, non-porous SiO2 layer was deposited on the surface. Microcapsules A with a diameter of 50-80 μm were obtained by sieving.

[0106] Example 2

[0107] Linear busbar fabrication:

[0108] Cut the copper strip to the required length and use a five-axis precision CNC milling machine to machine a wedge-shaped array of protrusions at the connection point; ultrasonically clean it in a 60°C NaOH solution for 5 minutes, rinse it with water, then soak it in 10% dilute sulfuric acid for 30 seconds to remove the oxide layer, rinse it with deionized water, and blow it dry with a high-pressure air gun.

[0109] 50 vol% EP and 30 vol% BN fillers, along with 1 vol% BYK-110, 1 vol% BYK-066, and 3 vol% polyamide curing agent, were added to a high-speed disperser and dispersed at 2000 rpm for 30 minutes. The mixture was then transferred to a vertical ball mill and ground for 4 hours until the fineness was ≤25 μm. Finally, it was transferred to a low-speed mixing tank, and 15 vol% of microcapsules A prepared in Example 1 were slowly added. The mixture was stirred at 500 rpm for 30 minutes. The slurry was then transferred to a vacuum degassing machine and degassed at -0.095 MPa for 15 minutes to obtain the coating.

[0110] Secure the copper strip to the automatic spraying line. Use a high-pressure airless spraying system with a nozzle diameter of 1.2mm, a pressure of 0.5MPa, and a moving speed of 0.5m / s to spray evenly and allow it to level for 15 minutes.

[0111] The tubes are fed into a temperature-controlled oven for step curing: 80°C for 1 hour, then heated to 120°C and kept constant for 2 hours, before naturally cooling to room temperature to obtain the tubes.

[0112] Example 3

[0113] Terminal block preparation:

[0114] Bi2O3, SnO2 and NaF or fluoroborate powder were ball-milled at a ratio of 42:58:1 for 4 hours and passed through a 400-mesh sieve to obtain core material powder; gelatin and gum arabic were dissolved in water at 60°C to prepare 3% solutions.

[0115] The core material powder was dispersed in a gelatin solution, and a gum arabic solution was slowly added while adjusting the pH to 4.0, causing the two colloids with opposite charges to aggregate and encapsulate on the core material surface. The mixture was cooled to below 10°C, and glutaraldehyde was added to crosslink and cure the wall material. The mixture was then centrifuged and washed to remove residual reagents. Spray drying was performed, and the powder was collected and sieved to separate 1-3 μm microcapsules (B).

[0116] Potassium silicate inorganic glue, deionized water, BYK-110 and BYK-066 were added to a mixing vessel in parts by weight of 20, 15, 1 and 0.2 respectively and mixed at low speed. Then, 65 parts by weight of microcapsule B were slowly added and stirred at 200 rpm for 30 minutes. Vacuum degassing was then performed.

[0117] Using a 200-mesh stainless steel wire mesh, the screen is laser-etched according to the groove pattern. The connecting wires are fixed to the printing fixture with the groove facing upwards. The automatic printing machine scrapes the coating twice to ensure that the paste fully fills the groove.

[0118] The material is transferred to a curing oven, heated at a rate of 1.5℃ / min, held at 60℃ for 30 minutes, then heated to 120℃ and held for 60 minutes to obtain the wiring terminals.

[0119] Example 4

[0120] Connect the cable strip to the terminal block:

[0121] Align the connection area of ​​the terminal block in Example 3 with the connection part of the wire bar in Example 2;

[0122] Slowly apply pressure to the terminal block to 3 kN and hold for 2 seconds to crimp it to the wire bar;

[0123] Continue to steadily apply pressure to the target pressure value of 10 kN, hold for 2 seconds, and slowly release the pressure to complete the crimping.

[0124] Comparative Example 1

[0125] Commercially available terminal blocks are from Chint Group, model NH series; commercially available cable strips are from Sfield, material T2 copper, surface coated with insulating varnish. Terminal blocks and cable strips are installed using screws and rivets.

[0126] Test example:

[0127] Contact resistance tests were performed on the installation area of ​​Example 4 and the installation area of ​​the busbar and terminal block in Comparative Example 1 according to the IEC 61238-1 standard. The specific results are shown in Table 1.

[0128] Temperature rise tests were conducted on the installation area of ​​Example 4 and the installation area of ​​the cable trays and terminals in Comparative Example 1 in accordance with the IEC 60512-5-2 standard. The specific results are shown in Table 1.

[0129] The short-circuit current withstand capability of the installation area in Example 4 and the installation area of ​​the busbar and terminal block in Comparative Example 1 were tested according to the IEC 61238-1 standard. The specific results are shown in Table 1.

[0130] Mechanical durability (vibration) tests were conducted on the installation area of ​​Example 4 and the installation area of ​​the cable tray and terminal block in Comparative Example 1 according to IEC 60068-2-6 standard. The specific results are shown in Table 1.

[0131] According to the IEC 60068-2-11 (salt spray) standard, the installation area of ​​Example 4 and the installation area of ​​the cable tray and terminal block in Comparative Example 1 were subjected to climate durability tests. The specific results are shown in Table 1.

[0132] Tensile strength tests were conducted on the installation area of ​​Example 4 and the installation area of ​​the cable tray and terminal block in Comparative Example 1 according to the IEC 61238-1 standard. The specific results are shown in Table 1.

[0133] Table 1. Statistical Table of Parameters for Examples and Comparative Examples

[0134]

[0135] In summary, this invention provides a busbar, terminal block structure, and distribution cabinet. By introducing a "wedge-shaped protrusion-groove" mechanical structure and a "cleaning-welding" microcapsule chemical system, it achieves a paradigm shift in electrical connection technology. Firstly, the high shear force and precise triggering provided by the "wedge-shaped protrusion-groove" structure cause microcapsule B to rupture preferentially. Subsequently, pressure triggers the rupture of microcapsule A. The Zn mixed powder and the low-melting-point solder oxide composite powder undergo a solid-state displacement reaction, generating a low-temperature eutectic liquid phase. The energy released by the reaction cleans the metal surface, while the liquid metal wets the clean metal surface, forming an atomically metallurgically bonded weld, improving the stability of the installation point. From "physical contact" to "metallurgical bonding," contact resistance and energized temperature rise are significantly reduced. Furthermore, the low-temperature solid-state welding forms a metallurgical bond, replacing unstable mechanical point contact and eliminating fundamental factors causing increased resistance, such as oxide films and fretting wear on the contact surface.

[0136] Furthermore, the microcapsules A in the non-installation areas act as functional fillers, enhancing the mechanical strength and thermal conductivity of the insulation coating. Under normal operating conditions, the core material slowly leaks out, and the leaked zinc powder and other metal powders react with O2, H2O, and Cl- that have entered the environment, preventing oxidation of the copper substrate of the busbar and repairing microscopic defects in the insulation layer.

[0137] By incorporating complex processes into microcapsules and mechanical structures, the results are guaranteed by the materials and structures themselves. During installation, only the installation pressure needs to be controlled to achieve consistent installation. At the same time, the process is simplified from "cleaning - applying paste - tightening - verification" to "alignment - pressing" in one step, improving installation efficiency.

[0138] 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 preferred examples and are not intended to limit 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 the present invention is defined by the appended claims and their equivalents.

Claims

1. A busbar, comprising a conductive substrate and an insulating layer covering its surface, characterized in that, Microcapsules A are uniformly dispersed within the insulating layer; The core of microcapsule A contains a reducing mixture; The conductive substrate has several sets of mounting points on its front end face, and the front end face of each mounting point has several sets of wedge-shaped protrusion arrays.

2. The busbar according to claim 1, characterized in that, The reducing mixture specifically comprises 60 wt% ultrafine zinc powder; 20 wt% nano zinc oxide; and 20 wt% nano-flaky boehmite.

3. The busbar according to claim 1, characterized in that, The microcapsule A has a core-shell-within-a-shell structure, with its inner wall material being mesoporous silica and its outer wall material being dense silica.

4. The busbar according to claim 3, characterized in that, The thickness of the mesoporous silica layer is 20-30 nm, and the thickness of the dense silica layer is 80-100 nm.

5. A terminal block structure, comprising a terminal conductor and an insulating housing, wherein the terminal conductor is provided with a connection area for crimping with any one of the wire bars according to claims 1-4, characterized in that, The connecting area is provided with an array of wedge-shaped grooves that match the wedge-shaped protrusion; Microcapsules B are attached to the inner wall of the wedge-shaped groove; The core of the microcapsule B contains low-melting-point solder oxide composite powder. When the terminal block is crimped with the wire bar, the meshing pressure of the wedge-shaped protrusion and the wedge-shaped groove causes the microcapsule A and the microcapsule B to rupture in sequence. The released reducing mixture mixes with the low-melting-point solder oxide composite powder and achieves electrical connection through a solid displacement reaction.

6. The terminal block according to claim 5, characterized in that, The low-melting-point solder oxide composite powder comprises, by mass percentage: 98%–99% of a mixture of bismuth oxide and tin oxide, and 1%–2% of sodium fluoride or fluoroborate.

7. The terminal block according to claim 6, characterized in that, The molar ratio of bismuth oxide to tin oxide is 42:

58.

8. The terminal block according to claim 5, characterized in that, The depth of the wedge-shaped groove is less than the height of the wedge-shaped protrusion, forming a height interference fit; the width of the wedge-shaped groove is greater than the width of the wedge-shaped protrusion, forming a width clearance fit.

9. A power distribution cabinet, comprising a cabinet body, wherein a plurality of DIN rails and busbars are arranged inside the cabinet body, characterized in that, It also includes the cable trays of any one of claims 1-4 and the terminal blocks of any one of claims 5-8, installed inside the cabinet; Specifically, several sets of terminals are mounted side-by-side on a DIN rail and electrically connected to the busbar via a wedge-shaped groove array and a wedge-shaped protrusion array; the rear end face of the busbar is electrically connected to the busbar.

10. A method for electrically connecting a busbar to a terminal block, characterized in that, Applied to any of the wire bars of claims 1-4 and any of the terminals of claims 5-8, the method includes the following steps: Alignment steps: Align the connection area of ​​the terminal block with the mounting point of the cable strip; Crimping step: Apply pressure to the terminal block to crimp it to the wire bar; The applied pressure is 10-15 kN; during the pressing process, the pressure causes microcapsules A and B to rupture, and the released reducing mixture mixes with the low-melting-point solder oxide composite powder to undergo a solid displacement reaction. Connection steps: The liquid metal generated by the reaction wets and connects the metal surfaces of both sides, forming a metallurgical bond and achieving electrical conductivity. Several sets of terminals are then pressed sequentially onto the mounting points on the front end of the busbar to complete the installation of the busbar and terminals.

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