Connecting structure of aluminum-based bus duct with copper-clad end part

Abstract

The utility model discloses a connecting structure of an aluminum-based bus duct with copper-clad end parts, and relates to the technical field of busbars. The copper-aluminum eutectic conducting bar comprises a copper-aluminum eutectic conducting bar body, the copper-aluminum eutectic conducting bar body comprises an aluminum alloy base body layer A, the end portions of the upper side face and the lower side face of the aluminum alloy base body layer A are covered with copper connecting layers A, and the copper-aluminum eutectic layer A is arranged between the aluminum alloy base body layer A and the copper connecting layers A. The copper-aluminum eutectic conducting bar further comprises a connector which comprises a plurality of copper-aluminum eutectic connecting pieces. The copper-aluminum eutectic conducting bar is clamped by the connector and tightly abuts against the copper-aluminum eutectic connecting piece. The beneficial effects of the utility model lie in that the utility model combines the advantages of low density and low cost of aluminum and the characteristics of high conductivity and corrosion resistance of copper, and only the end part of the aluminum substrate is coated with copper, so that the overall cost is reduced, the excellent performance of key parts is ensured, the perfect balance between the performance and the cost is realized, and the copper-aluminum eutectic technology is adopted. The problems that interface bonding is not firm, resistance is large, and corrosion is prone to occurring when aluminum and copper are directly connected are effectively solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to busbar technology field especially relates to a kind of connection structure of aluminium base end copper clad bus duct. BACKGROUND

[0002] In power transmission and distribution systems, the conductive busbar as a key component, responsible for efficient, safe transmission of electric energy, the traditional conductive busbar material mainly has copper and aluminum two, copper conductive busbar because of its excellent electrical conductivity and good mechanical strength and widely welcomed, but high cost and greater density limit its use in certain weight sensitive or cost has strict requirements application, aluminum conductive busbar although cost is lower and density is small, but its electrical conductivity and mechanical strength are relatively low, especially in high temperature or harsh environment, its performance decline is more obvious.

[0003] In order to combine the advantages of copper and aluminum, industry began to explore the use of composite conductive busbar, among which the aluminum base end copper clad conductive busbar is an innovative design, this kind of conductive busbar covers a layer of copper on the end of aluminum alloy matrix, which not only maintains the advantages of low cost and low density of aluminum, but also utilizes the high electrical conductivity and good corrosion resistance of copper, thereby achieving an optimized balance between performance and cost.

[0004] However, the existing copper-aluminum composite material is basically copper and aluminum directly solid-solid composite, and the direct connection between aluminum and copper often has the problem of poor interface bonding. In actual application, due to the large difference in physical and chemical properties between copper and aluminum, direct bonding can cause potential difference due to different materials, thereby easily causing problems of electrochemical corrosion and increased contact resistance. In addition, the aluminum base end copper clad conductive busbar also faces a major challenge of how to ensure reliable connection between aluminum and copper. Due to the large difference in physical and chemical properties between aluminum and copper, traditional connection methods such as welding and pressure bonding often fail to ensure the stability and durability of the connection, especially under harsh conditions such as high current, high temperature or vibration, the connection is prone to looseness or even breakage, which seriously affects the performance and safety of the conductive busbar.

[0005] Based on this, the applicant proposes a connection structure of aluminum base end copper clad bus duct to solve the above technical problems. CONTENT OF THE UTILITY MODEL

[0006] The utility model provides a kind of connection structure of aluminium base end copper clad bus duct to solve above technical problems in view of the deficiency in the prior art.

[0007] The utility model solves the above technical problems by the following technical solutions:

[0008] The application discloses a connecting structure of an aluminum-based end copper-clad bus duct, which comprises a copper-aluminum eutectic conductive row, wherein the copper-aluminum eutectic conductive row comprises an aluminum alloy base layer A, the end of the aluminum alloy base layer A on the upper and lower two sides is covered with a copper connecting layer A, and a copper-aluminum eutectic layer A is arranged between the aluminum alloy base layer A and the copper connecting layer A; and the connecting structure further comprises a connector, wherein the connector comprises a plurality of copper-aluminum eutectic connecting pieces, the copper-aluminum eutectic conductive row is clamped by the connector and tightly abuts against the copper-aluminum eutectic connecting pieces.

[0009] Preferably, after the copper-aluminum eutectic conductive row is connected with the connector, the outer side boundary of the copper connecting layer A is equivalent to or exceeds the boundary of the copper-aluminum eutectic connecting piece.

[0010] Preferably, the length of the copper connecting layer A arranged at the end of the aluminum alloy base layer A accounts for 2% to 15% of the total length.

[0011] Preferably, the thickness of the copper connecting layer A is 5% to 35% of the thickness of the copper-aluminum eutectic conductive row.

[0012] Preferably, the thickness of the copper-aluminum eutectic conductive row is 1 mm to 5 mm.

[0013] Preferably, the thickness of the copper connecting layer A is 0.1 mm to 0.5 mm.

[0014] Preferably, the copper-aluminum eutectic conductive row further comprises a P1 row, and the thickness of the P1 row is 0.5 mm to 2.5 mm.

[0015] Preferably, the copper-aluminum eutectic connecting piece comprises an aluminum alloy base layer B, the aluminum alloy base layer B is covered with a copper connecting layer B on the connecting surface corresponding to the copper-aluminum eutectic conductive row, and a copper-aluminum eutectic layer B is arranged between the aluminum alloy base layer B and the copper connecting layer B.

[0016] Preferably, the thickness of the copper connecting layer B is 5% to 35% of the thickness of the copper-aluminum eutectic connecting piece.

[0017] Preferably, the thickness of the copper-aluminum eutectic connecting piece is 1 mm to 5 mm.

[0018] Preferably, the thickness of the copper connecting layer B is 0.1 mm to 0.5 mm.

[0019] Preferably, the outer side of the copper connecting layer A is electroplated with a tin connecting layer A, and the outer side of the copper connecting layer B is electroplated with a tin connecting layer B.

[0020] The outer side of the copper connecting layer A is electroplated with a silver connecting layer A, and the outer side of the copper connecting layer B is electroplated with a silver connecting layer B.

[0021] The application has the following beneficial effects:

[0022] 1. Optimization of performance and cost: The connection structure of the utility model combines the low density and low cost advantages of aluminum with the high conductivity and corrosion resistance characteristics of copper. Through the design of covering copper only on the end of the aluminum base, the overall cost is reduced, and the excellent performance of the key part is ensured, realizing the perfect balance of performance and cost.

[0023] 2. Significant improvement of connection reliability: The copper-aluminum eutectic technology is adopted, and through solid-liquid compounding, the copper and aluminum are metallurgically combined to form a stable eutectic layer between the aluminum alloy base and the copper connection layer, effectively solving the problems of loose interface bonding, high resistance and easy corrosion between aluminum and copper. This eutectic connection not only improves the mechanical strength of the connection, but also significantly reduces the contact resistance, ensuring the stable performance of the conductive row under harsh conditions such as high current, high temperature or vibration.

[0024] 3. Simplification and optimization of connection structure: The connection structure of the utility model uses copper-aluminum eutectic connectors, which utilize several copper-aluminum eutectic connecting pieces and copper-aluminum eutectic conductive rows to achieve fast, simple and reliable connection. At the same time, the close fit between the connector and the conductive row also reduces the connection resistance and improves the conductivity efficiency.

[0025] 4. Enhancement of corrosion resistance: The copper connection layer is plated with a tin connection layer on the outside, which not only improves the corrosion resistance of the connection part, but also enhances the overall durability of the conductive row. This design effectively resists external environmental erosion and prolongs the service life of the conductive row.

[0026] 5. Flexibility and adaptability: By adjusting the thickness ratio of the aluminum alloy base and the copper connection layer, as well as the overall thickness design of the conductive row, the connection structure of the utility model can flexibly adapt to the needs of different application scenarios. Whether it is the aerospace field with high lightweight requirements or the power transmission system with high conductivity requirements, an appropriate product solution can be found. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the following will describe the drawings needed to be used in the embodiment or prior art description. Obviously, the technical solutions described in combination with the drawings are only some embodiments of the utility model, and for those skilled in the art, other embodiments and drawings can be obtained without creative labor.

[0028] Figure 1 is the connection state three-dimensional structure schematic diagram of the utility model.

[0029] Figure 2 is the connection state three-dimensional structure schematic diagram of the utility model.

[0030] Figure 3 is the connection state three-dimensional structure section view of the utility model.

[0031] Figure 4 is the copper-aluminum eutectic conductive row hierarchical structure schematic view of the utility model.

[0032] Figure 5 is the copper-aluminum eutectic conductive row hierarchical structure schematic view of the utility model.

[0033] Figure 6 is the copper-aluminum eutectic connecting piece hierarchical structure section view of the utility model.

[0034] Figure 7 is the copper-aluminum eutectic connecting piece hierarchical structure section view of the utility model.

[0035] Figure 8 is the copper-aluminum eutectic connecting piece hierarchical structure schematic view of the utility model.

[0036] Figure 9 is the connection schematic view of the utility model.

[0037] Figure 10 is the bus duct schematic view of the utility model.

[0038] In the figure: 1, copper-aluminum eutectic conductive row, 11, P1 row, 101, aluminum alloy base layer A, 102, copper connecting layer A, 103, copper-aluminum eutectic layer A, 104, tin connecting layer A, 2, connector, 21, copper-aluminum eutectic connecting piece, 211, aluminum alloy base layer B, 212, copper connecting layer B, 213, copper-aluminum eutectic layer B, 214, tin connecting layer B. DETAILED DESCRIPTION

[0039] The technical solutions of the various embodiments of the utility model will be described clearly and completely in combination with the drawings below, obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments described in the utility model, all other embodiments obtained by the person skilled in the art without creative labor are within the scope of the utility model. Embodiment 1:

[0040] As Figures 1 to 4 , Figures 6 to 7 , Figures 9 to 10As shown, the present invention discloses a connection structure for an aluminum-based copper-coated busbar trough, comprising a copper-aluminum eutectic conductive busbar 1. The copper-aluminum eutectic conductive busbar 1 includes an aluminum alloy substrate layer A101, with copper connecting layers A102 covering the upper and lower ends of the aluminum alloy substrate layer A101. A copper-aluminum eutectic layer A103 lies between the aluminum alloy substrate layer A101 and the copper connecting layer A102. The thickness of the copper-aluminum eutectic conductive busbar 1 is 5 mm, and the thickness of the copper connecting layer A102 is 0.5 mm. The copper-aluminum eutectic conductive busbar 1 also includes a P1 bar 11 with a thickness of 2.5 mm. Furthermore, it includes a connector 2, which comprises several copper-aluminum eutectic connecting pieces 21. The copper-aluminum eutectic conductive busbar 1 is clamped by the connector 2 and connected to the copper-aluminum eutectic connecting pieces 21. The copper connecting layer A102, which is provided at the end of the aluminum alloy substrate layer A101, accounts for 2% to 15% of the total length. After the copper-aluminum eutectic conductive bus 1 is connected to the connector 2, the outer boundary of the copper connecting layer A102 is equal to or exceeds the boundary of the copper-aluminum eutectic connecting piece 21. The copper-aluminum eutectic connecting piece 21 includes an aluminum alloy substrate layer B211. A copper connecting layer B212 is covered on the aluminum alloy substrate layer B211 corresponding to the connecting surface of the copper-aluminum eutectic conductive bus 1. A copper-aluminum eutectic layer B213 is located between the aluminum alloy substrate layer B211 and the copper connecting layer B212. The thickness of the copper-aluminum eutectic connecting piece 21 is 3 mm, the thickness of the copper connecting layer B212 is 0.3 mm, and the thickness of the copper-aluminum eutectic layer B213 is 5 micrometers to 50 micrometers.

[0041] The connection structure of this utility model combines the advantages of low density and low cost of aluminum with the high conductivity and corrosion resistance of copper. By covering the aluminum substrate with copper only at the ends, the overall cost is reduced while ensuring the excellent performance of key parts, achieving a perfect balance between performance and cost.

[0042] Compared to traditional connection methods such as electroplating and brazing, the design using copper-aluminum eutectic busbars and copper-aluminum eutectic connectors increases heat dissipation, reduces the connection temperature under the same current carrying capacity, avoids damage to materials from high temperatures, and also reduces high-cost processes such as electroplating, thereby improving production efficiency and economy.

[0043] like Figure 5 , Figure 8 As shown, in another embodiment, the copper connection layer A102 is electroplated with a tin connection layer A104 on the outside, and the copper connection layer B212 is electroplated with a tin connection layer B214 on the outside. Tin plating prevents surface oxidation, improves the corrosion resistance of the connection parts, and enhances the overall durability of the busbar. This design effectively resists the erosion of the external environment and extends the service life of the busbar.

[0044] The copper connecting layer A102 is plated with a silver connecting layer A on the outside, and the copper connecting layer B212 is plated with a silver connecting layer B on the outside, so that the conductivity can be improved after silver plating.

[0045] In the above embodiment, the connector 2 comprises a plurality of insulating mounting plates arranged between the two end covers, and the copper-aluminum eutectic connecting plates 21 are arranged on the insulating mounting plates.

[0046] The copper-aluminum eutectic refers to a low-melting-point eutectic alloy formed between copper and aluminum under certain temperature and pressure. This eutectic alloy has good wettability and fluidity, can fill the small gap between copper and aluminum, and form a firm bond. At the same time, the copper-aluminum eutectic layer also has good electrical conductivity and corrosion resistance, which can improve the overall performance of the connector.

[0047] The insulating mounting plate comprises one single-sided groove insulating mounting plate and four double-sided groove insulating mounting plates. The number of single-sided groove insulating mounting plates and double-sided groove insulating mounting plates is set according to actual needs, and is matched with the bus duct. The single-sided groove insulating mounting plate is arranged adjacent to the end cover, and the double-sided groove insulating mounting plate is arranged between the single-sided groove insulating mounting plate and another end cover. One copper-aluminum eutectic connecting plate 21 is arranged on the single-sided groove insulating mounting plate, and two copper-aluminum eutectic connecting plates 21 are symmetrically arranged on the double-sided groove insulating mounting plate.

[0048] The connecting cavities for clamping the copper-aluminum eutectic conductive row 1 are formed between adjacent insulating mounting plates, and the connecting cavities for clamping the P1 row 11 are formed between the end cover and the adjacent double-sided groove insulating mounting plate.

[0049] The end cover is provided with a protrusion in the middle of the side facing the insulating mounting plate, and a gap is formed between the protrusion and the adjacent single-sided groove insulating mounting plate, which is matched with the attached side plate of the bus duct. The end cover is provided with a mounting cavity on the side away from the insulating mounting plate, and a gasket is arranged in the mounting cavity. The design of the protrusion and the mounting cavity on the end cover enhances the structural strength of the device, and facilitates installation and fixation.

[0050] The insulating sleeve penetrates the end cover, the insulating mounting plate and the copper-aluminum eutectic connecting plate 21. After the bus torque bolt penetrates the insulating sleeve, the nut is tightened at the end to clamp the copper-aluminum eutectic conductive row 1, thereby ensuring the stability and safety of the connection.

[0051] The copper-aluminum eutectic conductive row 1 is stacked in the bus duct, and an insulating layer is arranged on the copper-aluminum eutectic conductive row 1 to avoid short circuit caused by mutual connection, and the insulating layer can be a single-layer polyester film, and the smooth surface of the polyester film can prevent the film from being damaged due to mutual extrusion and friction when the copper-aluminum eutectic conductive row 1 is stacked, although the single-layer polyester film is very thin, but still affects heat dissipation, and the copper-aluminum eutectic conductive row 1 can improve heat dissipation, and the higher the row width is, the better the heat dissipation is, and the base layer of the copper-aluminum eutectic conductive row 1 is an aluminum alloy base layer A101, and compared with a copper row, the copper-aluminum eutectic conductive row 1 has better heat dissipation under the same weight or the same cost.

[0052] The copper-aluminum eutectic conductive row 1 and the copper-aluminum eutectic connecting piece 21 are both copper-aluminum eutectic composite materials, and a production process of the copper-aluminum eutectic composite material is provided, which relates to copper plate surface pretreatment, copper plate preheating, solid-liquid composite casting and rolling, composite slab homogenization annealing, cold rolling, secondary annealing and slitting and cutting.

[0053] Step A: copper plate surface pretreatment: the copper plate is first subjected to high-pressure washing to quickly remove solid impurities on the surface of the copper plate, then subjected to low-pressure washing for degreasing treatment to remove grease on the surface of the copper plate, and then subjected to steel brush equipment polishing to remove the oxide layer on the surface of the copper plate, and finally the copper plate is dried for standby;

[0054] Step B: copper plate preheating: the pretreated copper plate is fixedly sent to a feeding device, and heated to 150 DEG C ~ 220 DEG C in an oxygen-free environment;

[0055] Step C: solid-liquid composite casting and rolling: the aluminum ingot is heated to 660 DEG C ~ 710 DEG C to obtain molten aluminum liquid, then inert gas is introduced near the roller to fill the casting and rolling environment to form an oxygen-free environment, and the outer surface temperature of the roller is heated to 85 DEG C ~ 95 DEG C, cooling liquid is introduced into the roller, and the casting and rolling equipment is started to make the molten aluminum liquid and the treated copper plate contact in the oxygen-free environment to realize solid-liquid composite oxygen-free continuous casting and rolling, and obtain a copper-aluminum composite slab;

[0056] Step D: composite slab homogenization annealing: the obtained copper-aluminum composite slab is put into an annealing furnace for homogenization annealing;

[0057] Step E: cold rolling: the annealed composite slab is subjected to secondary rolling to adjust the rolling equipment to obtain the required plate thickness and plate width, and the final plate thickness after secondary rolling is 0.2 mm ~ 16 mm, wherein the thickness of the copper plate is 5% ~ 35% of the thickness of the whole composite plate, and the plate width is 600 mm ~ 1200 mm;

[0058] Step F: secondary annealing: the copper-aluminum composite plate after cold rolling is subjected to secondary annealing;

[0059] Step G: slitting and cutting.

[0060] In step A, the rinsing liquid is an alkaline degreasing liquid at 50-70℃.

[0061] In step A, the steel brush equipment not only polishes off the oxide layer on the surface of the copper plate, but also increases the roughness of the surface, increases the copper-aluminum composite area, and thus enhances the adhesion of the composite material.

[0062] In step B, the preheating of the copper plate can increase the atomic thermal activation energy, so that the atoms can obtain sufficient energy in a short time at high temperature to migrate and form a thicker eutectic layer, thereby effectively improving the bonding strength of the copper-aluminum composite interface.

[0063] In step C, the inert gas is nitrogen, and the introduction of nitrogen can avoid the formation of an oxide layer on the copper plate and aluminum liquid during the compounding process due to direct exposure to air, which can prevent the formation of an ideal eutectic layer and adversely affect the peel strength of the material.

[0064] In step C, the introduction of cooling liquid into the roller can increase the cooling speed of the casting and rolling, forming smaller grains, thereby increasing the material strength. The rolling speed of the roller is 600-1300 mm / min, the temperature of the cooling liquid is 20-30℃, and the cooling rate is 300-1000℃ / s.

[0065] In step C, the compounding rate after solid-liquid compounding casting and rolling is 100%.

[0066] In step D, the heating temperature of the homogenization annealing process is 430-510℃, and the annealing time is 4-5h. The homogenization annealing process can reduce the segregation of the copper-aluminum alloy on both sides, remove residual stress, and improve the performance of the alloy.

[0067] In step F, the heating temperature of the secondary annealing process is 300-350℃, and the cooling temperature in the annealing furnace is below 80℃. The secondary annealing process can refine the grains, adjust the structure, and eliminate structural defects. Since there is a certain internal stress during rolling, it can reduce the strength of the composite material. The use of annealing process can reduce residual stress, stabilize size, reduce deformation and crack tendency, and ensure that the product has good comprehensive mechanical properties and good metallurgical bonding.

[0068] The copper-aluminum eutectic composite material has not been affected by the skin effect of current transmission, and the current-carrying capacity is about 85% of that of pure copper conductor. Compared with the copper bar, the consumption of copper material is reduced, and the production cost is saved.

[0069] The copper-aluminum eutectic composite material produced by the process has high shear strength and peeling strength, can realize metallurgical bonding between the composite metals, form a eutectic layer, and meet the bonding strength of the material.

[0070] In the embodiment, to obtain the copper-aluminum eutectic conductive bar 1 and the copper-aluminum eutectic connecting piece 21 meeting the requirements, the related parameters in the production process of the copper-aluminum eutectic composite material are adjusted appropriately, so that the composite material obtained by processing meets the requirements.

[0071] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as illustrative and not restrictive. The scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and range of the equivalent elements of the claims are intended to be embraced in the present application. Any reference signs in the claims should not be considered as limiting the claims involved.

[0072] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A connecting structure of an aluminum-based end portion of a copper-clad bus duct, characterized by: The copper-aluminum eutectic conductive row (1) comprises an aluminum alloy base layer A (101), the end of the upper and lower sides of the aluminum alloy base layer A (101) is covered with a copper connecting layer A (102), and a copper-aluminum eutectic layer A (103) is arranged between the aluminum alloy base layer A (101) and the copper connecting layer A (102). The connector (2) comprises a plurality of copper-aluminum eutectic connecting pieces (21), the copper-aluminum eutectic conductive row (1) is clamped by the connector (2) and tightly abuts against the copper-aluminum eutectic connecting pieces (21).

2. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 1, wherein: After the copper-aluminum eutectic conductive row (1) is connected with the connector (2), the outer side boundary of the copper connecting layer A (102) is equivalent to or exceeds the boundary of the copper-aluminum eutectic connecting piece (21).

3. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 1, wherein: The length of the copper connecting layer A (102) arranged at the end of the aluminum alloy base layer A (101) accounts for 2% to 15% of the total length.

4. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 1, wherein: The thickness of the copper connecting layer A (102) is 5% to 35% of the thickness of the copper-aluminum eutectic conductive row (1).

5. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 4, characterized in that: The thickness of the copper-aluminum eutectic conductive row (1) is 1mm to 5mm.

6. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 5, wherein: The thickness of the copper connecting layer A (102) is 0.1mm to 0.5mm.

7. The connecting structure of an aluminum-based end-of-copper bus duct according to claim 1, wherein: The copper-aluminum eutectic connecting piece (21) comprises an aluminum alloy base layer B (211), a copper connecting layer B (212) is arranged on the connecting surface of the aluminum alloy base layer B (211) corresponding to the copper-aluminum eutectic conductive row (1), and a copper-aluminum eutectic layer B (213) is arranged between the aluminum alloy base layer B (211) and the copper connecting layer B (212).

8. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 7, characterized in that: The thickness of the copper connecting layer B (212) is 5% to 35% of the thickness of the copper-aluminum eutectic connecting piece (21).

9. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 7, wherein: The outer side of the copper connecting layer A (102) is electroplated with a tin connecting layer A (104), and the outer side of the copper connecting layer B (212) is electroplated with a tin connecting layer B (214).

10. The connecting structure of the aluminum-based end-of-copper bus duct according to claim 7, wherein: The outer side of the copper connecting layer A (102) is electroplated with a silver connecting layer A, and the outer side of the copper connecting layer B (212) is electroplated with a silver connecting layer B.

Images