Structure, electric drive system and vehicle implementing laser welding of aluminum and copper dissimilar conductors

Abstract

The application provides a structure, an electric driving system and a vehicle for realizing laser welding of aluminum and copper heterogeneous conductors, and relates to the technical field of welding.The structure for realizing laser welding of aluminum and copper heterogeneous conductors comprises an aluminum conductor, a copper conductor and a copper-aluminum composite part, wherein the copper-aluminum composite part comprises an aluminum side part and a copper side part, the aluminum side part is connected with the aluminum conductor through laser welding, and the copper side part is connected with the copper conductor through laser welding to form a connecting path between the aluminum conductor and the copper conductor.The structure for realizing laser welding of aluminum and copper heterogeneous conductors can realize reliable connection between the aluminum conductor and the copper conductor, ensure the mechanical performance, electrical performance and reliability of the joint between the aluminum conductor and the copper conductor, save installation space, reduce the overall weight, simplify the production process and reduce the production cost by laser welding the aluminum side part of the copper-aluminum composite part with the aluminum conductor and laser welding the copper side part of the copper-aluminum composite part with the copper conductor.

Description

Technical Field

[0001] This application relates to the field of welding technology, and in particular to a structure, electric drive system, and vehicle for realizing laser welding of dissimilar conductors such as aluminum and copper. Background Technology

[0002] In the electronic control system of new energy vehicles, the power circuit needs to achieve efficient conductivity through conductive materials (such as copper and aluminum). Due to the excellent electrical and thermal conductivity of copper, the insulated gate bipolar transistor (IGBT) module in the electronic control system usually uses copper or copper alloys as the conductor material.

[0003] However, with the global shortage of copper resources and rising costs, aluminum conductors, which are less dense and cheaper, are gradually being introduced into power circuit systems.

[0004] However, aluminum and copper, as dissimilar conductors, face technical challenges when joining, especially in laser welding processes. How to achieve a reliable connection has become an urgent problem for the industry to solve. Utility Model Content

[0005] In view of the above problems, this application provides a structure, electric drive system and vehicle for realizing laser welding of aluminum and copper dissimilar conductors, so as to solve the problem that it is difficult to achieve reliable connection of aluminum and copper dissimilar conductors in the prior art electric drive system.

[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0007] The first aspect of this application provides a structure for laser welding of dissimilar conductors such as aluminum and copper, comprising:

[0008] Aluminum conductor;

[0009] Copper conductor;

[0010] A copper-aluminum composite component includes an aluminum side portion and a copper side portion. The aluminum side portion is connected to an aluminum conductor by laser welding, and the copper side portion is connected to a copper conductor by laser welding to form a connection path between the aluminum conductor and the copper conductor.

[0011] In one possible implementation, the structure for laser welding of dissimilar conductors aluminum and copper has a first direction, a second direction, and a third direction that intersect each other in pairs; the aluminum side portion and the copper side portion are butted side by side along the first direction; the aluminum conductor overlaps on one side of the aluminum side portion along the third direction, and the copper conductor overlaps on one side of the copper side portion along the third direction.

[0012] After laser welding, the aluminum side portion and the aluminum conductor form a first weld, which extends along a second direction, and a first lap surface is formed between the aluminum side portion and the aluminum conductor; when projected along a third direction, the projection of the first weld is located within the projection area of ​​the first lap surface.

[0013] After laser welding, the copper side portion and the copper conductor form a second weld, which extends along a second direction, and a second lap surface is formed between the copper side portion and the copper conductor; when projected along a third direction, the projection of the second weld is located within the projection area of ​​the second lap surface.

[0014] In one possible implementation, projection is made along a third direction, with the centerline of the first weld coinciding with the centerline of the first lap surface, and the centerline of the second weld coinciding with the centerline of the second lap surface.

[0015] In one possible implementation, the width of the first overlapping surface along the first direction is W1 mm, where W1 satisfies W1≥6.

[0016] And / or, the width of the second overlapping surface along the first direction is W2 mm, where W2 satisfies W2≥4.

[0017] In one possible implementation, the copper-aluminum composite further includes a transition interface; the transition interface is disposed between the aluminum-side portion and the copper-side portion.

[0018] In one possible implementation, the distance between the center of the first weld and the transition interface along the first direction is W3 mm, where W3 satisfies W3≥4.

[0019] And / or, the distance between the center of the second weld and the transition interface along the first direction is W4 mm, where W4 satisfies W4≥4.

[0020] In one possible implementation, the aluminum conductor and the copper conductor are spaced apart along a first direction and projected along a third direction, with the aluminum conductor and the copper conductor respectively disposed on both sides of the transition interface along the first direction.

[0021] In one possible implementation, the aluminum conductor and the copper conductor are disposed on the same side of the copper-aluminum composite along a third direction;

[0022] Alternatively, aluminum conductors and copper conductors may be respectively disposed on both sides of the copper-aluminum composite component along a third direction.

[0023] A second aspect of this application provides an electric drive system including the structure described above for laser welding of dissimilar conductors, aluminum and copper.

[0024] A third aspect of this application provides a vehicle including the electric drive system described above.

[0025] The structure provided in this application for laser welding of dissimilar conductors of aluminum and copper achieves a reliable connection between the aluminum and copper conductors by setting a copper-aluminum composite component between the aluminum conductor and the copper conductor, laser welding the aluminum conductor to the aluminum side of the copper-aluminum composite component, and laser welding the copper conductor to the copper side of the copper-aluminum composite component. This ensures the mechanical, electrical, and reliability properties of the joint between the aluminum and copper conductors, and also saves installation space, reduces overall weight, simplifies the production process, and lowers production costs.

[0026] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the structure, electric drive system, and vehicle for laser welding of dissimilar conductors of aluminum and copper provided by the embodiments of this application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A cross-sectional view of the structure for laser welding of dissimilar conductors aluminum and copper provided in the first embodiment of this application;

[0029] Figure 2 for Figure 1 The top view of the structure for laser welding of dissimilar conductors aluminum and copper is shown.

[0030] Figure 3 for Figure 1 The diagram shows the dimensions of a structure for laser welding aluminum and copper dissimilar conductors.

[0031] Figure 4 This is a cross-sectional view of the structure for laser welding of dissimilar conductors aluminum and copper provided in the second embodiment of this application;

[0032] Figure 5 A cross-sectional view of the structure for laser welding of dissimilar conductors aluminum and copper provided in the third embodiment of this application;

[0033] Figure 6 This is a cross-sectional view of the structure for laser welding of dissimilar conductors aluminum and copper provided in the fourth embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 10. Aluminum conductor; 20. Copper conductor; 30. Copper-aluminum composite; 31. Aluminum side portion; 32. Copper side portion; 33. Transition interface; 41. First weld; 42. Second weld; 51. First lap joint surface; 52. Second lap joint surface; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0036] First, those skilled in the art should understand that these embodiments are merely for explaining the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0037] Secondly, it should be noted that, in the description of the embodiments of this application, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0038] As described in the background section, electric drive systems in related technologies face the challenge of achieving reliable, low-cost, and compact connections between dissimilar conductors like aluminum and copper. The inventors have discovered that this problem arises because: if aluminum and copper are directly joined by laser welding, brittle intermetallic compounds such as Cu2Al4 and Cu4Al9 are generated in the weld, leading to deterioration of the joint's mechanical properties and affecting connection reliability. Furthermore, aluminum conductors have lower mechanical properties than copper conductors, making the aluminum conductor at the dissimilar conductor joint a weak point in mechanical performance during the service life of the electric control system, increasing the risk of structural failure. If aluminum and copper are connected by bolts, the direct bolting of bare aluminum and copper accelerates corrosion in the connection area due to the potential difference. Using aluminum electroplating increases manufacturing complexity and cost. Moreover, bolting requires significant structural and operational space, resulting in structural redundancy, which does not align with the trend towards compact electric control systems in new energy vehicles. If aluminum and copper dissimilar conductors are joined by non-fusion welding, the joint mechanical properties of the non-fusion welding process are low, and the requirements for manufacturing space and process control are high, which poses a risk of reliability failure. Moreover, compared with laser welding, the manufacturing space and difficulty of non-fusion welding of aluminum and copper dissimilar conductors are greater when connecting the whole structure.

[0039] To address the aforementioned technical problems, embodiments of this application provide a structure, electric drive system, and vehicle for laser welding of dissimilar conductors of aluminum and copper. The structure for laser welding of dissimilar conductors of aluminum and copper includes: an aluminum conductor; a copper conductor; and a copper-aluminum composite component, including an aluminum-side portion and a copper-side portion. The aluminum-side portion is connected to the aluminum conductor by laser welding, and the copper-side portion is connected to the copper conductor by laser welding, thereby forming a connection path between the aluminum conductor and the copper conductor.

[0040] The structure provided in this application for laser welding of dissimilar conductors of aluminum and copper achieves a reliable connection between the aluminum and copper conductors by setting a copper-aluminum composite component between the aluminum conductor and the copper conductor, laser welding the aluminum conductor to the aluminum side of the copper-aluminum composite component, and laser welding the copper conductor to the copper side of the copper-aluminum composite component. This ensures the mechanical, electrical, and reliability properties of the joint between the aluminum and copper conductors, and also saves installation space, reduces overall weight, simplifies the production process, and lowers production costs.

[0041] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] Please refer to Figures 1-6 The first aspect of this application provides a structure for laser welding of dissimilar conductors, aluminum and copper, comprising:

[0043] Aluminum conductor 10;

[0044] 20 copper conductors;

[0045] The copper-aluminum composite component 30 includes an aluminum side portion 31 and a copper side portion 32. The aluminum side portion 31 is connected to the aluminum conductor 10 by laser welding, and the copper side portion 32 is connected to the copper conductor 20 by laser welding to form a connection path between the aluminum conductor 10 and the copper conductor 20.

[0046] It should be noted that in related technologies, aluminum and copper have poor miscibility in the liquid state, and direct laser welding will cause a violent reaction, generating a series of high-hardness, high-brittle intermetallic compounds (such as Cu2Al4 and Cu4Al9). These brittle intermetallic compounds are distributed in the weld, severely deteriorating the mechanical properties of the joint, making it extremely prone to microcracks and propagation under vibration or thermal stress, leading to connection failure. The structure for laser welding of dissimilar conductors aluminum and copper provided in this application introduces a copper-aluminum composite 30, laser welding the aluminum conductor 10 to the aluminum side portion 31 of the copper-aluminum composite 30, and laser welding the copper conductor 20 to the copper side portion 32 of the copper-aluminum composite 30. This decomposes the welding of dissimilar materials of aluminum and copper into aluminum-aluminum homologous material welding and copper-copper homologous material welding. In homologous metal welding, no harmful brittle phases are generated, and the weld itself has excellent ductility and strength, fundamentally avoiding the problem of weld embrittlement and improving the mechanical reliability, vibration resistance, and fatigue resistance of the joint.

[0047] In related technologies, aluminum conductors generally have lower strength and hardness than copper conductors, making them prone to becoming mechanical weak points in dissimilar material joints. The brittle welds produced by direct laser welding further exacerbate the risk of this weak point. The structure provided in this application for laser welding of dissimilar conductors of aluminum and copper introduces a copper-aluminum composite component 30. The aluminum conductor 10 is laser-welded to the aluminum side portion 31 of the copper-aluminum composite component 30, and the copper conductor 20 is laser-welded to the copper side portion 32 of the copper-aluminum composite component 30. This decomposes the welding of dissimilar aluminum and copper materials into aluminum-aluminum homologous material welding and copper-copper homologous material welding. The weld strength of aluminum-aluminum homologous material welding and copper-copper homologous material welding is generally higher than that of the aluminum base material itself. This means that the strength bottleneck of the joint is no longer located at the weld but returns to the aluminum conductor body, maximizing the joint strength. Moreover, the copper-aluminum composite component 30 itself is an integral structure with high internal bonding strength, providing a stable path for force transmission, thereby improving the overall mechanical properties of the joint (tensile strength, shear strength). This avoids the problem of the aluminum conductor's weak mechanical properties or weld embrittlement becoming the source of failure, significantly enhancing the overall structural integrity.

[0048] In related technologies, connecting dissimilar conductors like aluminum and copper with bolts carries the risk of high contact resistance and corrosion leading to increased resistance. Cracks and brittle intermetallic compounds from direct laser welding also increase resistance and cause overheating. The structure provided in this application for laser welding dissimilar conductors like aluminum and copper, by introducing a copper-aluminum composite component 30, laser welds the aluminum conductor 10 to the aluminum side portion 31 of the composite component 30, and the copper conductor 20 to the copper side portion 32 of the composite component 30. This not only achieves complete metallurgical bonding with extremely low and stable contact resistance, but also fundamentally eliminates the possibility of electrochemical corrosion by avoiding direct contact between exposed aluminum and copper, ensuring long-term stability of electrical performance. This provides a low-impedance, high-current path with low heat generation and slow performance degradation, meeting the stringent electrical performance requirements of power circuits.

[0049] In related technologies, connecting dissimilar conductors like aluminum and copper with bolts requires additional screws, nuts, washers, and other parts. Furthermore, to prevent corrosion, aluminum busbars typically require electroplating, increasing material costs and complicating the electroplating process. The structure provided in this application for laser welding dissimilar conductors like aluminum and copper, by introducing a copper-aluminum composite component 30, laser welds the aluminum conductor 10 to the aluminum side portion 31 of the composite component 30, and the copper conductor 20 to the copper side portion 32 of the composite component 30. This eliminates the need for electroplating and fasteners, directly reducing material costs. Moreover, laser welding offers a high degree of automation, allowing for integration with robots to achieve rapid mass production, increasing production cycle time, reducing labor costs, thereby simplifying the production process, improving production efficiency, and lowering manufacturing costs.

[0050] In related technologies, connecting dissimilar conductors like aluminum and copper with bolts requires reserved installation space and increases the weight of fasteners, resulting in structural redundancy and bulkiness. The structure provided in this application for laser welding dissimilar conductors like aluminum and copper introduces a copper-aluminum composite component 30. The aluminum conductor 10 is laser-welded to the aluminum side portion 31 of the copper-aluminum composite component 30, and the copper conductor 20 is laser-welded to the copper side portion 32 of the copper-aluminum composite component 30. This results in a very compact joint with no additional parts, allowing for flexible layout in planar stacking or three-dimensional orientation. Furthermore, it reduces the weight of fasteners, further leveraging the lightweight advantage of aluminum conductors, thereby significantly saving installation space, reducing overall weight, and better meeting the development needs of highly integrated and compact new energy vehicle electronic control systems.

[0051] In summary, the structure for laser welding of dissimilar conductors aluminum and copper provided in this application, by setting a copper-aluminum composite component 30 between the aluminum conductor 10 and the copper conductor 20, laser welding the aluminum conductor 10 to the aluminum side portion 31 of the copper-aluminum composite component 30, and laser welding the copper conductor 20 to the copper side portion 32 of the copper-aluminum composite component 30, can achieve a reliable connection between the aluminum conductor 10 and the copper conductor 20, ensuring the mechanical properties, electrical properties and reliability of the joint between the aluminum conductor 10 and the copper conductor 20, and can also save installation space, reduce overall weight, simplify the production process and reduce production costs.

[0052] Moreover, by adopting the solution of this application, laser welding between various dissimilar materials such as aluminum conductors and copper conductors can be achieved.

[0053] In one possible implementation, please see Figure 1 and Figure 2 As shown, the structure for laser welding of dissimilar conductors of aluminum and copper has a first direction X, a second direction Y and a third direction Z that intersect each other in pairs; the aluminum side portion 31 and the copper side portion 32 are joined side by side along the first direction X; the aluminum conductor 10 overlaps on the side of the aluminum side portion 31 along the third direction Z, and the copper conductor 20 overlaps on the side of the copper side portion 32 along the third direction Z.

[0054] After laser welding, the aluminum side portion 31 and the aluminum conductor 10 form a first weld 41. The first weld 41 extends along the second direction Y, and a first lap surface 51 is formed between the aluminum side portion 31 and the aluminum conductor 10. Projecting along the third direction Z, the projection of the first weld 41 is located within the projection area of ​​the first lap surface 51.

[0055] After laser welding, the copper side portion 32 and the copper conductor 20 form a second weld 42. The second weld 42 extends along the second direction Y, and a second lap surface 52 is formed between the copper side portion 32 and the copper conductor 20. Projecting along the third direction Z, the projection of the second weld 42 is located within the projection area of ​​the second lap surface 52.

[0056] It should be noted that "side-by-side connection" means that the aluminum side portion 31 and the copper side portion 32 are arranged adjacently along the first direction X, and their opposite sides are in direct contact and are joined by metallurgical means, so that the copper-aluminum composite 30 forms an integral transition structure at the joint of the aluminum side portion 31 and the copper side portion 32.

[0057] In this embodiment, the first weld 41 extends along the second direction Y and is a continuous elongated strip, thereby increasing the effective connection length and bonding area between the aluminum side portion 31 and the aluminum conductor 10; the second weld 42 extends along the second direction Y and is a continuous elongated strip, thereby increasing the effective connection length and bonding area between the copper side portion 32 and the copper conductor 20, thus ensuring the mechanical and electrical properties of the joint and the reliability of the joint. The first lap surface 51 and the second lap surface 52 are the main parts that bear shear force and peel force; projected along the third direction Z, the projection of the first weld 41 is located within the projection area of ​​the first lap surface 51, and the projection of the second weld 42 is located within the projection area of ​​the second lap surface 52, thereby avoiding serious defects such as weld penetration, lack of fusion, and poor forming, ensuring that laser energy is used efficiently and uniformly to form a molten pool, thereby obtaining a continuous, uniform, and defect-free high-quality weld, thus ensuring the mechanical and electrical properties of the joint and the reliability of the joint.

[0058] In one possible implementation, please see Figure 3 As shown, when projected along the third direction Z, the center line of the first weld 41 coincides with the center line of the first lap surface 51, and the center line of the second weld 42 coincides with the center line of the second lap surface 52.

[0059] In this embodiment, the centerline of the first weld 41 coincides with the centerline of the first lap surface 51, and the centerline of the second weld 42 coincides with the centerline of the second lap surface 52. On the one hand, when the joint is subjected to tensile, shear, or vibration loads, the stress can be uniformly transferred to the weld through the entire lap surface and then uniformly distributed to the base material on the other side. This is beneficial to improving the fatigue resistance, vibration resistance, and overall mechanical reliability of the joint, ensuring the long service life of the connection structure under the harsh working conditions of new energy vehicles. On the other hand, after the current flows in from the lap surface, it can pass through the entire cross-section of the weld in the most direct and uniform way. The current density distribution is uniform, ensuring that the joint resistance is minimized and evenly distributed, avoiding the risk of local overheating, and ensuring the stability of the electrical connection and the ability to carry large currents.

[0060] In one possible implementation, please see Figure 3 As shown, the width of the first overlapping surface 51 along the first direction X is W1 mm, and W1 satisfies W1≥6.

[0061] And / or, the width of the second overlapping surface 52 along the first direction X is W2 mm, where W2 satisfies W2≥4.

[0062] In this embodiment, by satisfying W1≥6 and W2≥4, it can be ensured that the first lap surface 51 and the second lap surface 52 have sufficient width. This allows for a greater distance and a larger heat dissipation body between the welding heat source center of the first weld 41 and the second weld 42 and the brittle intermetallic compound layer inside the copper-aluminum composite 30. This effectively reduces the thermal shock of the welding thermal cycle to the bonding interface inside the copper-aluminum composite 30, prevents the brittle intermetallic compound layer pre-existing at the interface from becoming excessively thickened or coarsened due to overheating, and thus protects the performance of the copper-aluminum composite 30 itself, effectively improving the mechanical and electrical properties of the joint and the reliability of the joint.

[0063] Moreover, since the mechanical strength (such as yield strength and tensile strength) of aluminum is usually lower than that of copper, W1 can increase the connection area on the aluminum side by satisfying W1≥6 and W2 can increase the connection area on the aluminum side by satisfying W2≥4. This can compensate for the insufficient strength of the aluminum material itself, making the mechanical properties on both sides of the copper-aluminum composite 30 more matched, avoiding damage to the connection structure on the weaker aluminum side, and improving the overall reliability.

[0064] In one possible implementation, please see Figure 1 As shown, the copper-aluminum composite component 30 also includes a transition interface 33; the transition interface 33 is disposed between the aluminum side portion 31 and the copper side portion 32.

[0065] It should be noted that during the fabrication of the copper-aluminum composite 30, the transition interface 33 is formed under controlled conditions (such as through explosive bonding, rolling bonding, etc.). During this process, the temperature, pressure, and time at the interface between the aluminum-side portion 31 and the copper-side portion 32 can be precisely controlled, thereby generating a very thin, continuous, and uniform intermetallic compound layer. The thickness and morphology of this intermetallic compound layer are controlled within a set range for both mechanical and electrical properties, thus forming the transition interface 33 of the copper-aluminum composite 30.

[0066] In related technologies, during direct laser welding of aluminum and copper, the two react violently in the molten pool, randomly and disorderly generating coarse, blocky, brittle intermetallic compounds, severely damaging the joint performance. The structure provided in this application for laser welding of dissimilar conductors of aluminum and copper utilizes a copper-aluminum composite 30 placed between the aluminum conductor 10 and the copper conductor 20. The copper-aluminum composite 30 includes an aluminum-side portion 31, a copper-side portion 32, and a transition interface 33 between them. The transition interface 33 is formed during the manufacturing process of the copper-aluminum composite 30, and its thickness and morphology are controlled within a set range for both mechanical and electrical properties. By laser welding the aluminum conductor 10 to the aluminum-side portion 31 of the copper-aluminum composite 30, and laser welding the copper conductor 20 to the copper-side portion 32 of the copper-aluminum composite 30, the uncontrollable harmful factors (random intermetallic compounds) during welding are transformed into a pre-manufactured, controllable functional interface—the transition interface 33. This avoids the appearance of brittle phases in critical welds, fundamentally solving the core metallurgical problem of aluminum-copper laser welding.

[0067] Moreover, the transition interface 33 of the copper-aluminum composite 30 has sufficient bonding strength. When the joint is subjected to vibration, impact or thermal stress, the mechanical load can be smoothly and efficiently transferred between the aluminum side portion 31 and the copper side portion 32 through this high-strength interface 33, without delamination, peeling or breakage at the interface, thus ensuring the stability of the overall mechanical structure of the copper-aluminum composite 30.

[0068] In one possible implementation, please see Figure 3 As shown, the distance between the center of the first weld 41 and the transition interface 33 along the first direction X is W3 mm, and W3 satisfies W3≥4;

[0069] And / or, the distance between the center of the second weld 42 and the transition interface 33 along the first direction X is W4 mm, where W4 satisfies W4≥4.

[0070] It should be noted that if the distance between the first weld 41 or the second weld 42 and the transition interface 33 is too close, the high-temperature thermal cycle during welding will cause the intermetallic compound of the transition interface 33 to thicken excessively and the intermetallic compound grains to coarsen, which will seriously degrade the mechanical properties of the transition interface 33, making it more prone to microcracks and propagation, and may eventually cause the copper-aluminum composite 30 itself to crack or peel off at the interface.

[0071] In this embodiment, by ensuring that W3 satisfies W3≥4 and W4 satisfies W4≥4, the thermal shock of the welding thermal cycle to the transition interface 33 is greatly reduced, and the thickness and morphology of the intermetallic compound layer at the transition interface 33 are stabilized in the initial manufacturing state. This avoids performance degradation caused by secondary heating during welding, fundamentally ensuring the structural integrity and long-term reliability of the copper-aluminum composite 30, and effectively improving the mechanical and electrical properties of the joint as well as the reliability of the joint.

[0072] In one possible implementation, please see Figure 3 As shown, aluminum conductor 10 and copper conductor 20 are spaced apart along the first direction X and projected along the third direction Z. Aluminum conductor 10 and copper conductor 20 are respectively disposed on both sides of the transition interface 33 along the first direction X.

[0073] In this embodiment, by maintaining a physical distance between the aluminum conductor 10 and the copper conductor 20 along the first direction X and projecting them along the third direction Z, the aluminum conductor 10 and the copper conductor 20 are respectively disposed on both sides of the transition interface 33 along the first direction X. This ensures that there is no direct electrical connection path between the aluminum conductor 10 and the copper conductor 20 under any circumstances. It guarantees that the current between the aluminum conductor 10 and the copper conductor 20 must and can only be transmitted through the copper-aluminum composite 30, which is a unique and controlled channel. This avoids the possibility of direct short circuit between the aluminum conductor 10 and the copper conductor 20 due to installation errors, vibration, or foreign object intervention, and greatly improves the electrical safety and reliability of the system.

[0074] In one possible implementation, please see Figure 1 and Figure 4 As shown, aluminum conductor 10 and copper conductor 20 are disposed on the same side of copper-aluminum composite 30 along the third direction Z;

[0075] Alternatively, please see Figure 5 and Figure 6 As shown, aluminum conductor 10 and copper conductor 20 are respectively disposed on both sides of copper-aluminum composite 30 along the third direction Z.

[0076] It should be noted that, please refer to Figure 1 As shown, the copper-aluminum composite component 30 can be disposed below the aluminum conductor 10 and the copper conductor 20; please refer to... Figure 2 As shown, the copper-aluminum composite component 30 can also be disposed above the aluminum conductor 10 and the copper conductor 20; please refer to [link / reference]. Figure 5 As shown, the copper-aluminum composite component 30 can also be disposed below the aluminum conductor 10, while the copper-aluminum composite component 30 is disposed above the copper conductor 20; please refer to Figure 6As shown, the copper-aluminum composite component 30 can also be disposed above the aluminum conductor 10, while the copper-aluminum composite component 30 is disposed below the copper conductor 20, which has excellent spatial adaptability and layout flexibility, thus enabling it to adapt to different vehicle or electronic control system designs.

[0077] A second aspect of this application also provides an electric drive system, including the structure described above for laser welding dissimilar conductors of aluminum and copper.

[0078] The electric drive system provided in this application embodiment, by adopting the above-described structure for laser welding of dissimilar conductors of aluminum and copper, can achieve a reliable connection between aluminum conductor 10 and copper conductor 20, ensuring the mechanical properties, electrical properties and reliability of the joint between aluminum conductor 10 and copper conductor 20, and can also save installation space, reduce overall weight, simplify production process and reduce production costs.

[0079] A third aspect of this application also provides a vehicle including the electric drive system described above.

[0080] Given that the vehicle in this embodiment includes the structure or electric drive system for realizing laser welding of dissimilar conductors of aluminum and copper as described in any of the above embodiments, the structure and beneficial effects of the vehicle including the structure or electric drive system for realizing laser welding of dissimilar conductors of aluminum and copper will not be described in detail here.

[0081] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0082] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A structure for laser welding dissimilar conductors of aluminum and copper, characterized in that, include: Aluminum conductor (10); Copper conductor (20); The copper-aluminum composite (30) includes an aluminum side portion (31) and a copper side portion (32). The aluminum side portion (31) is connected to the aluminum conductor (10) by laser welding, and the copper side portion (32) is connected to the copper conductor (20) by laser welding to form a connection path between the aluminum conductor (10) and the copper conductor (20).

2. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 1, characterized in that, The structure for laser welding of dissimilar conductors of aluminum and copper has a first direction (X), a second direction (Y), and a third direction (Z) that intersect each other in pairs; the aluminum side portion (31) and the copper side portion (32) are joined side by side along the first direction (X); the aluminum conductor (10) overlaps on one side of the aluminum side portion (31) along the third direction (Z), and the copper conductor (20) overlaps on one side of the copper side portion (32) along the third direction (Z); After laser welding, the aluminum side portion (31) and the aluminum conductor (10) form a first weld (41), the first weld (41) extends along the second direction (Y), and a first lap surface (51) is formed between the aluminum side portion (31) and the aluminum conductor (10); when projected along the third direction (Z), the projection of the first weld (41) is located within the projection area of ​​the first lap surface (51); The copper side portion (32) is laser welded to the copper conductor (20) to form a second weld (42), the second weld (42) extends along the second direction (Y), and a second lap surface (52) is formed between the copper side portion (32) and the copper conductor (20); the projection of the second weld (42) is located in the projection area of ​​the second lap surface (52) along the third direction (Z).

3. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 2, characterized in that, Projecting along the third direction (Z), the centerline of the first weld (41) coincides with the centerline of the first lap surface (51), and the centerline of the second weld (42) coincides with the centerline of the second lap surface (52).

4. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 2, characterized in that, The width of the first overlapping surface (51) along the first direction (X) is W1 mm, where W1 satisfies W1≥6; And / or, the width of the second overlapping surface (52) along the first direction (X) is W2 mm, where W2 satisfies W2≥4.

5. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 2, characterized in that, The copper-aluminum composite (30) further includes a transition interface (33); the transition interface (33) is disposed between the aluminum side portion (31) and the copper side portion (32).

6. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 5, characterized in that, The distance between the center of the first weld (41) and the transition interface (33) along the first direction (X) is W3 mm, where W3 satisfies W3≥4; And / or, the distance between the center of the second weld (42) and the transition interface (33) along the first direction (X) is W4 mm, where W4 satisfies W4≥4.

7. The structure for laser welding of dissimilar conductors aluminum and copper according to claim 5, characterized in that, The aluminum conductor (10) and the copper conductor (20) are spaced apart along the first direction (X) and projected along the third direction (Z). The aluminum conductor (10) and the copper conductor (20) are respectively disposed on both sides of the transition interface (33) along the first direction (X).

8. The structure for laser welding of dissimilar conductors aluminum and copper according to any one of claims 2-7, characterized in that, The aluminum conductor (10) and the copper conductor (20) are disposed on the same side of the copper-aluminum composite (30) along the third direction (Z); Alternatively, the aluminum conductor (10) and the copper conductor (20) may be disposed on both sides of the copper-aluminum composite (30) along the third direction (Z).

9. An electric drive system, characterized in that, The structure includes the structure for laser welding of dissimilar conductors of aluminum and copper as described in any one of claims 1 to 8.

10. A vehicle, characterized in that, Including the electric drive system as described in claim 9 above.

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