A connecting copper bar

Abstract

The utility model discloses a kind of connecting copper bars, applied to power electronics equipment technical field, including copper bar body, copper bar body is used to connect with aluminium bar;Two copper bar panels, be in the end of copper bar body, the end of two copper bar panels has open slot, two copper bar panels between there is spacing to form the slot width of open slot;Two groups of clamping claws, respectively be in the two sides of copper bar panel, clamping claw is stretched from the side of one of copper bar panel and end points to another copper bar panel, there is interval between the clamping claw of two sides to form the slot length of open slot;When aluminium bar is connected with copper bar body, aluminium bar is inserted into open slot, the two board surfaces of aluminium bar are respectively welded with two copper bar panels, the two side surfaces of aluminium bar are respectively welded with the inner wall of clamping claw.Connect aluminium bar by setting clamping claw and open slot in copper bar, and it is big to resist pullout force, reliable connection, simultaneously discard additional connecting tool, process is extremely simple, cost reduction.

Description

Technical Field

[0001] This utility model relates to the field of power electronic equipment technology, and in particular to a connecting copper busbar. Background Technology

[0002] Currently, in the photovoltaic and energy storage industry, conventional inductors often use connectors or fixed fixtures to ensure high-reliability welding between the multi-strand aluminum wire winding leads and the copper busbars. However, when welding multi-strand aluminum wire leads in parallel, they are prone to spreading and shifting, leading to incomplete welds (industry defect rate >15%). In copper-aluminum welding, the copper-aluminum contact area must be at least three times the cross-sectional area of ​​the aluminum wire. This is a strict requirement based on four core factors: electrical performance, thermal management, mechanical reliability, and interfacial chemical stability. However, using connectors or fixtures only allows copper and aluminum to contact on one side, resulting in excessively large solder joints. Furthermore, using connectors or fixtures only allows copper and aluminum to contact on one side, and the introduction of foreign objects through the gaps in the aluminum wires increases contact resistance. Traditional clamping also introduces foreign objects, increasing contact resistance. Transition connectors increase interfacial resistance points (e.g., copper-aluminum composite terminals increase resistance by 40%). Welding heat input damages the inductor core (>200℃ leads to a 10% decrease in permeability).

[0003] In conclusion, how to effectively solve the above problems is an urgent issue that needs to be addressed by those skilled in the art. Utility Model Content

[0004] The purpose of this invention is to provide a copper busbar connection method that connects to aluminum busbars by setting claws and slots on the copper busbar. This method has high tensile strength and reliable connection, while eliminating the need for additional connecting tools, simplifying the process and reducing costs.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A connecting copper busbar, comprising:

[0007] A copper busbar body, which is used to connect to an aluminum busbar;

[0008] Two copper busbar panels are disposed at the ends of the copper busbar body. The ends of the two copper busbar panels have open slots, and there is a gap between the two copper busbar panels to form the width of the open slots.

[0009] Two sets of claws are respectively disposed on both sides of the copper busbar panel. The claws extend from the side of one of the copper busbar panels and point to the other copper busbar panel. There is a gap between the claws on both sides to form the groove length of the opening slot.

[0010] When the aluminum busbar is connected to the copper busbar body, the aluminum busbar is inserted into the opening slot, the two plates of the aluminum busbar are respectively welded to the two copper busbar panels, and the two sides of the aluminum busbar are respectively welded to the inner wall of the claw.

[0011] Optionally, it also includes a base plate located at the interface line between the copper busbar body and the copper busbar panel. The base plate forms the bottom surface of the opening groove. When the aluminum busbar is connected to the copper busbar body, the bottom surface of the aluminum busbar contacts the base plate.

[0012] Optionally, the middle part of the copper busbar body is bent to form two sub-copper busbars, the two sub-copper busbars are attached together, one of the sub-copper busbars extends outward to form a copper busbar panel, and the other sub-copper busbar extends outward to form the base plate and the other copper busbar panel.

[0013] Optionally, the two sets of claws extend from the same copper busbar panel, with the ends of the claws extending beyond the other copper busbar panel. After the aluminum busbar is connected to the copper busbar body, the portion of the claw ends extending beyond the other copper busbar panel is pressed against the other copper busbar panel.

[0014] Optionally, after the portion of the claw end that extends beyond the other copper busbar panel presses against the copper busbar panel, the extended portions on both sides are opposite each other and there is a gap between them;

[0015] Alternatively, the portion of the claw end on one side that extends beyond the other copper busbar panel may cover the length of the opening slot.

[0016] Optionally, the copper busbar panel has multiple vertically arranged claws on both sides, with gaps between the claws on the same side and the claws on both sides placed at the gaps on opposite sides.

[0017] Optionally, each set of claws includes a first claw body and a second claw body extending from the two copper busbar panels respectively, with the ends of the first claw body and the second claw body facing each other. After the aluminum busbar is connected to the copper busbar body, the first claw body and the second claw body are pressed against the aluminum busbar.

[0018] Optionally, the upper edges of the two copper busbar panels are flush, and the upper edge of the claw is lower than the upper edge of the copper busbar panels.

[0019] Optionally, the claw and the copper busbar panel are provided with protrusions on the side facing the opening slot, and when the aluminum busbar is connected to the copper busbar body, the protrusions abut against the aluminum busbar.

[0020] Optionally, the copper busbar panel is provided with a boss, the direction of which is perpendicular to the insertion and removal direction of the aluminum busbar into the opening slot, and the aluminum busbar is provided with a slot, wherein the boss engages with the slot when the aluminum busbar is connected to the copper busbar body.

[0021] The beneficial effects of this utility model are as follows: The connecting copper busbar provided by this utility model has two copper busbar panels at the end of the copper busbar body, and two sets of claws on the left and right sides of the copper busbar panels. The two copper busbar panels and the two sets of claws form an opening groove. When the aluminum busbar is connected to the copper busbar body, the aluminum busbar is inserted into the opening groove, and the surface of the aluminum busbar plate is tightly fitted with the inner surface of the copper busbar panel. The left and right sides of the aluminum busbar are in full contact with the inner wall of the claws, forming a four-sided fully enclosed weldable interface. Subsequently, the two plates of the aluminum busbar are welded to the two copper busbar panels respectively, and the two sides of the aluminum busbar are welded to the inner wall of the claws respectively, forming a continuous four-sided weld. The copper-aluminum welding area is increased, and the pull-out force of the copper busbar and aluminum wire is significantly improved. At the same time, the four-sided welds work together to absorb the stress of thermal expansion and contraction, resulting in lower connection resistance and longer service life.

[0022] The connecting copper busbar provided by this utility model eliminates the need for additional connecting tools. The claws and the slot are the connector. The copper busbar panel carries the main current, the slot positions the aluminum busbar, and the claws have both mechanical anchoring and auxiliary conductivity functions. The process is extremely simple and the cost is reduced. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the first copper busbar substrate provided in a specific embodiment of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of the structure of the first type of copper busbar substrate after bending;

[0026] Figure 3 This is a schematic diagram of the first type of copper busbar connection;

[0027] Figure 4 A schematic diagram of a second copper busbar substrate provided in a specific embodiment of this utility model;

[0028] Figure 5 This is a schematic diagram of the second type of copper busbar connection;

[0029] Figure 6 This is a schematic diagram of the aluminum busbar structure;

[0030] Figure 7 This is a schematic diagram showing the connection between the aluminum busbar and the second type of copper busbar.

[0031] Figure 8 This is a schematic diagram of the third type of copper busbar connection;

[0032] Figure 9 This is a schematic diagram of the third type of copper busbar connection;

[0033] Figure label:

[0034] 1-Claw; 2-Protrusion; 3-Copper busbar body; 4-Soldering groove; 5-Boss; 6-Opening groove; 7-Claw slot. Detailed Implementation

[0035] The core of this utility model is to provide a copper busbar connection method that connects aluminum busbars by setting claws and opening slots on the copper busbar. This method has high tensile strength and reliable connection, while eliminating the need for additional connecting tools, simplifying the process and reducing costs.

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] In one specific implementation, please refer to Figures 1 to 9 The connecting copper busbar provided by this utility model includes:

[0038] The copper busbar body 3 is used to connect with the aluminum busbar. The copper busbar body 3 is a common type of copper busbar on the market, made of T2 or TU1 oxygen-free copper, with a thickness depending on the rated current, typically 3-12mm. The copper busbar body 3 can be rectangular, chamfered rectangular, or I-shaped, which helps reduce weight and increase heat dissipation surface. Preferably, it is entirely tin-plated to prevent copper oxidation.

[0039] Two copper busbar panels are located at the ends of the copper busbar body 3. Each copper busbar panel has an opening groove 6 at its end. The inner side of the copper busbar panel facing the aluminum busbar can be brushed or micro-sandblasted to increase roughness and improve the interdiffusion area of ​​metal atoms during welding; the outer side retains the original tin plating layer, balancing corrosion resistance and conductivity. The inlet of the opening groove 6 can be chamfered to prevent scratching the oxide layer of the aluminum busbar during insertion and to facilitate alignment during automatic insertion. The bottom of the opening groove 6 can be rounded to avoid stress concentration leading to fatigue cracking.

[0040] Two sets of claws 1 are respectively located on the left and right sides of the copper busbar panel. The claws 1 extend from the side of one of the copper busbar panels and point to the other copper busbar panel. Preferably, the claws 1 extend integrally along the side of the copper busbar panel and bend towards each other, with the ends pointing to the opposite copper busbar panel. The two sets of claws 1 and the two copper busbar panels together form a pocket-shaped opening slot 6 with only the tail end open.

[0041] The opening slot 6 is slightly larger than the cross-section of the aluminum busbar, ensuring smooth insertion and providing welding clamping force. There is a gap between the two copper busbar panels to form the width of the opening slot 6, and a gap between the claws 1 on both sides to form the length of the opening slot 6. The width of the opening slot 6 is determined by the distance between the two copper busbar panels, and is slightly larger than the thickness of the aluminum busbar, ensuring smooth insertion and reserving longitudinal filling space for the weld pool; the length is determined by the inward distance of the claws 1 on both sides, and is slightly larger than the width of the aluminum busbar, reserving lateral filling space for the weld pool.

[0042] When connecting the aluminum busbar to the copper busbar body 3, the aluminum busbar is inserted into the opening slot 6. After insertion, a crimping machine is used to press the claws 1 inward, ensuring a tight fit between the aluminum busbar plate and the inner surface of the copper busbar plate. The left and right sides of the aluminum busbar are in full contact with the inner wall of the claws 1, forming a four-sided fully enclosed weldable interface, eliminating the risk of relative displacement between the aluminum and copper busbars. Subsequently, the two plates of the aluminum busbar are welded to the two copper busbar plates respectively, and the two sides of the aluminum busbar are welded to the inner wall of the claws 1 respectively, forming a continuous four-sided weld seam for a highly reliable connection. Various welding methods can be used, such as brazing (e.g., tin-lead soldering, jet welding), copper-aluminum fusion welding (e.g., resistance welding), and ultrasonic welding. After welding, the copper-aluminum interface is hook-shaped and fused together, maintaining the conductive cross-section without compromising the strength of the copper busbar body 3.

[0043] The pocket-type full-envelope structure improves upon the traditional copper-aluminum wire contact by creating a four-sided enveloping surface contact. Claw 1 guides and pre-locks, eliminating aluminum busbar wobbling. During welding, current / laser is simultaneously injected into the copper busbar panel and claw 1, allowing for simultaneous melting on all four sides. This ensures uniform heat distribution and prevents warping caused by uneven thermal expansion in single-sided welds. The open slot 6 envelops the aluminum conductor on all four sides, increasing the copper-aluminum welding area. The four weld seams share the mechanical load, significantly improving the pull-out force between the copper busbar and the aluminum wire. Simultaneously, the four weld seams collaboratively absorb thermal expansion and contraction stress, resulting in lower connection resistance and longer lifespan. If connecting two-strand aluminum wires to a copper busbar, only the welding effect at the contact surface between the aluminum wire and the copper busbar needs to be considered; the welding condition between the two aluminum wires is not required, and there is no external clamp contacting the welding interface.

[0044] Under the condition that the copper-aluminum contact area is ≥ 3 times the cross-sectional area of ​​the aluminum wire, the copper-aluminum contact length can be shortened by half, and the solder joint volume is smaller. The copper busbar panel carries the main current, the cross-sectional area of ​​the copper busbar body remains unchanged, the current density does not increase, and the system loss does not increase. The chuck 1 has both mechanical anchoring and auxiliary conduction functions. The pre-clamping design eliminates complex fixtures, significantly shortens the production line cycle time, and improves efficiency and reliability.

[0045] The connecting copper busbar provided by this utility model eliminates the need for a connector that connects copper and aluminum busbars. The claw 1 and the opening slot 6 serve as the connector, requiring no additional parts or tooling, simplifying the process and reducing costs. After crimping, it surrounds the copper busbar on all four sides, providing high tensile strength. It is compatible with various welding methods such as laser, resistance, and friction welding, ensuring a strong and reliable connection.

[0046] In some embodiments, a base plate is also included. The base plate is located at the interface line between the copper busbar body 3 and the copper busbar panel. The bottom surface of the base plate forms the opening groove 6. When the aluminum busbar is connected to the copper busbar body 3, the bottom surface of the aluminum busbar contacts the base plate.

[0047] It should be noted that a horizontal base plate is added at the interface between the copper busbar body 3 and the copper busbar panel. This base plate is integrally formed with the two copper busbar panels and the copper busbar body 3, or connected in one step by friction welding or laser welding, forming the bottom surface of the opening slot 6. When the aluminum busbar is inserted into the opening slot 6, its bottom surface fits against the inner surface of the base plate, limiting the insertion depth of the aluminum busbar and ensuring consistent insertion depth, avoiding deformation caused by excessive pushing during manual or automatic assembly. Furthermore, the base plate can provide an additional conductive cross-section, allowing current to be directly diverted to the aluminum busbar through the base plate, shortening the current path and reducing contact resistance.

[0048] In a preferred embodiment, the bottom surface of the aluminum busbar is welded to the base plate, achieving a fifth-sided welding contact, thus upgrading the original frame-type interface, which was only covered from all four sides, to a basin-type fully enclosed structure. During welding, the base plate and the bottom surface of the aluminum busbar form a large-area molten pool. After cooling and solidification, a transverse anchoring band is generated, locking the aluminum busbar within the opening groove 6 to resist peeling and shear stress.

[0049] In some embodiments, the middle part of the copper busbar body 3 is bent to form two sub-copper busbars, the two sub-copper busbars are attached together, one sub-copper busbar extends outward to form a copper busbar panel, and the other sub-copper busbar extends outward to form a base plate and another copper busbar panel.

[0050] It should be noted that the connecting copper busbar in this application can be formed using an integrated molding method of first blanking and then folding, taking conventional copper strip and punching or cutting it to obtain an unfolded part of a predetermined shape, such as... Figure 1 and Figure 4 As shown, bend along the preset creases, bending both ends of the copper plate to the same side to make the upper and lower copper plates fit tightly together, forming a double copper busbar. A polytetrafluoroethylene (PTFE) pad is added to the inside during bending to prevent damage. After bending, the gap between the two layers is small, and it can be considered a single conductive cross-section with a current capacity comparable to the entire board.

[0051] One of the copper busbars retains its full width at its end, forming the first copper busbar panel. The other copper busbar's end is first bent 90° away from the first copper busbar panel, leaving the width of the opening slot 6 base plate, and then bent upwards at 90°, forming the base plate on the flat side and the second copper busbar panel on the vertical side. On the claw strips pre-reserved on the outer sides of the two copper busbar panels, after the aluminum busbar is inserted into the opening slot 6, the claw strips are bent 90° towards the opposite copper busbar panel, forming claws 1. If claw 1 extends beyond the opposite copper busbar panel, claw 1 is bent inwards to ensure its inner wall fits against the copper busbar panel. During the bending process, it is necessary to maintain the right angle of the bend, ensure the regular shape of the opening slot 6, ensure uniform welding gaps, and ensure stable welding quality. Preferably, the intersection of the base plate and the two copper busbar panels is rounded to eliminate stress concentration and facilitate the flow of the weld pool.

[0052] The relative positions of the two copper busbar panels, claw 1, and base plate are determined by the same blank datum, with no cumulative tolerance, ensuring the consistency of the dimensions of the batch opening slots 6 and meeting the requirements of automatic insertion. The base plate, claw 1, and double copper busbar panels are obtained in one go, without the need for additional welding or riveting. This retains the complete conductive cross-section and forms a five-sided fully enclosed basin-shaped welding cavity, significantly reducing interface resistance and thermal stress. No die-casting mold is required, resulting in zero mold costs and a simple and reliable process.

[0053] It should be noted that the copper busbar panel and the copper busbar body 3 can be arranged parallel to each other, in which case the opening direction of the slot 6 is the same as that of the copper busbar body 3; the copper busbar panel and the copper busbar body 3 can also be arranged perpendicularly, in which case the opening direction of the slot 6 is perpendicular to that of the copper busbar body 3, both of which are within the protection scope of this application.

[0054] In some embodiments, two sets of claws 1 extend from the same copper busbar panel, with the ends of the claws 1 extending beyond the other copper busbar panel. After the aluminum busbar is connected to the copper busbar body 3, the portion of the claw 1 extending beyond the other copper busbar panel is pressed against the other copper busbar panel.

[0055] It should be noted that the two sets of claws 1 are not symmetrically distributed on both side panels, but are all punched or wire-cut directly from the side edge of the same copper busbar panel (denoted as the first copper busbar panel) to form a cantilever beam. The claw body first extends vertically outward along the side edge of the first copper busbar panel, then bends 90°, crosses the slot width space, and extends towards the opposite second copper busbar panel, with the final end extending beyond the outer side of the second copper busbar panel by a certain length, forming the overhanging part.

[0056] The forming of the chuck 1 is preferably achieved by stamping or CNC bending, with the bending radius being 1-1.5 times the thickness of the chuck to prevent copper material from cracking. The bending angle is slightly less than 90°, such as 85°–88°, to allow for springback. After the copper elasticity springs back, it is exactly perpendicular to the copper busbar panel, which eliminates work hardening and ensures that the chuck 1 is perpendicular to the copper busbar panel after clamping, continuously providing pre-clamping force to the aluminum busbar.

[0057] For example, each side is provided with 2-4 claws 1, the claw 1 is 5-50mm wide, the claw spacing is 2-10mm, the root of the claw 1 is provided with an arc at the connection with the first copper busbar panel to reduce stress concentration; the claw thickness is equal to the thickness of the first copper busbar panel to ensure that the current can be shunted along the claw body without adding extra resistance.

[0058] In its free state without the aluminum busbar inserted, the extended portion of the chuck 1 maintains a negative gap with the outer surface of the second copper busbar panel, and has a certain preload.

[0059] After the aluminum busbar is inserted, the excess part of the claw 1 is pushed outward. Utilizing the elastic rebound of the copper, the excess part is pressed against the outer wall of the second copper busbar panel, generating a continuous surface-to-surface clamping force. The clamping force is large enough to achieve mechanical self-locking before welding, preventing assembly misalignment or springback loosening.

[0060] After crimping, the excess portion and the outer wall of the second copper busbar panel can be left untreated, or the claw tip can be fused to the outer wall of the second copper busbar panel using laser or resistance welding, thus maintaining the conductive cross section and forming a permanent mechanical lock.

[0061] Preferably, the extended portion of the claw 1 is provided with an inlet bevel to facilitate gradual expansion when the aluminum bar is inserted, thus avoiding scratching the oxide layer on the aluminum surface.

[0062] The bottom of the opening slot 6 can retain the base plate (see the aforementioned embodiment). The bottom surface of the aluminum busbar abuts against the base plate to achieve axial limit. The height direction is positioned by the base plate, the front and rear positions are positioned by the copper busbar panel, and the left and right positions are positioned by the claw 1. The excess part is exactly aligned with the outer wall of the second copper busbar panel, forming multi-directional constraints. It can enter the welding station without additional fixtures.

[0063] As can be seen from the above, the continuous compressive stress provided by the excess portion ensures that the copper-aluminum interface remains in close contact during thermal cycling, preventing the aluminum strip from slipping.

[0064] In some embodiments, the claw 1 extends from one side of the copper busbar panel, with its end crossing the entire width of the slot and extending beyond the outer wall of the opposite copper busbar panel. The extended portion can be arranged in two ways:

[0065] In the first type, after the portion of the claw 1 that extends beyond the other copper busbar panel presses against the copper busbar panel, the extended portions on both sides are opposite each other with a gap between them. The claws 1 on both sides are short claws 1. The extended portion of this claw 1 is relatively short, with small deformation and stable springback. The locking force is evenly distributed along the length of the groove, avoiding the phenomenon of the middle section floating up that may occur on the continuous long side, and maintaining contact pressure for a long time.

[0066] The ends of the two claws 1 face each other on the outer wall of the opposite copper busbar panel, maintaining intermittent gaps to form an elastic release channel. The two claws 1 extend and retract independently, and the thermal stress is released in the gaps, avoiding bending fatigue caused by the overall expansion of the continuous long side.

[0067] The second type involves a single claw 1 extending beyond the other copper busbar panel, covering the length of the opening slot 6. This means the claw 1 on the same side extends continuously, with a single claw 1 covering the entire length of the opening slot 6; this is a long claw 1. The claw 1 has a larger contact area with the copper busbar panel, resulting in greater clamping force and providing a continuous conductive strip. The current density distribution is more uniform, and compared to a short claw 1, fewer forming processes are required for the same contact area.

[0068] It should be noted that when a single claw 1 covers the entire length of the opening slot 6, the claws 1 on both sides can be staggered vertically or cross-staggered. Alternatively, the claws 1 on both sides can be stacked and pressed together on the copper busbar panel, forming micro-friction damping in the overlapping area, so that vibration energy is consumed at multiple points.

[0069] In some embodiments, the copper busbar panel has multiple vertically arranged claws 1 on both sides, with gaps between the claws 1 on the same side, and the claws 1 on both sides are placed in the gaps on opposite sides. The above structure can realize that the claws 1 on both sides are arranged in an alternating or cross manner, which is applicable to both short claws 1 and long claws 1.

[0070] For example, when the gap is greater than the width of the jaw 1 and the gap is aligned with the jaw 1, the jaws 1 on both sides are arranged alternately, and the jaws 1 on both sides do not overlap or contact each other, and appear as a comb when viewed from above.

[0071] Example 1: A claw 1 is provided on each side of the copper busbar panel. The claws 1 on both sides are staggered vertically. When the copper busbar panel is pressed, the claws 1 on both sides are arranged in an alternating vertical arrangement.

[0072] Example 2: One first claw is provided on one side of the copper busbar panel, and two independent second claws are provided on the other side. A gap is left between the two second claws, which is larger than the width of the first claw. At the same time, the positions of the first claw and the second claw are staggered, that is, the first claw is directly opposite the gap between the second claws, and the claws on both sides are arranged in a crisscross pattern when the copper busbar panel is pressed.

[0073] Example 3: Multiple claws 1 are provided on both sides of the copper busbar panel. There is a gap between adjacent claws 1, and the claws 1 on both sides are staggered. When pressing the copper busbar panel, the claws 1 on both sides are arranged in a cross pattern.

[0074] During deformation, each claw 1 extends and retracts independently, with consistent springback. The deformation is fully released within the gap, and the locking force is uniform along the length without interference in the thickness direction. This avoids the inability to fully release deformation due to cumulative deformation and mutual interference, thus ensuring that the claw 1 presses the copper busbar panel stably and reliably.

[0075] When the gap is less than the width of claw 1 or when claw 1 is not aligned with the gap on the opposite side, the claws 1 on both sides are arranged vertically and crosswise, with an overlapping area in the thickness direction, partially or completely overlapping each other. The overlapping area generates surface contact or micro-friction, which can provide additional shear resistance and damping. Deformation differences can be released by sliding within the overlapping surface, reducing bending stress. For example, the claws 1 on both sides are staggered by half a claw distance in the groove length direction, forming a staggered arrangement, which allows for elastic deformation of each claw and provides micro-friction damping during vibration.

[0076] In a preferred embodiment, the ends of the claws 1 on the same side are connected by a connecting plate, and multiple claws 1 become a whole. The contact area between the claws 1 and the copper busbar panel is increased, and the clamping force is increased.

[0077] In some embodiments, each set of claws 1 includes a first claw body and a second claw body extending from two copper busbar panels respectively, with the ends of the first claw body and the second claw body facing each other. In other words, the first claw body is integrally stamped and bent from the side edge of the first copper busbar panel, while the second claw body extends symmetrically from the side edge of the second copper busbar panel, and the two extend towards each other along the slot width direction to form an embracing pattern.

[0078] The bottom of the slot 6 retains the base plate, and the bottom surface of the aluminum busbar abuts against the base plate to achieve axial limit. At this time, the two claws are located in the center area of ​​the aluminum busbar thickness. The height direction is positioned by the base plate, the front and back positions are positioned by the two copper busbar panels, and the left and right positions are positioned by the two side clamps. It can enter the welding station without additional clamps.

[0079] During the insertion of the aluminum busbar, the first and second claws elastically deform outward, opening synchronously like jaws. After the aluminum busbar is in place, the two claws generate opposing clamping forces due to elastic rebound, forming symmetrical face-to-face pressing bands. The pressure is sufficient to achieve mechanical self-locking before welding, preventing assembly misalignment or loosening due to springback. After the aluminum busbar is connected to the copper busbar body 3, the first and second claws press against the side wall of the aluminum busbar, forming two new parallel conductive paths. During welding, laser or resistance welding is used to form continuous welds on the corresponding surfaces of the two claw tongues and the aluminum busbar, ensuring both the metallurgical bond between copper and aluminum and maintaining the conductive cross-section.

[0080] As can be seen from the above, the opposing pressing causes the aluminum busbar to be subjected to symmetrical pressure in the thickness direction. During thermal expansion, the sliding forces on the front and rear surfaces of the aluminum busbar cancel each other out, the sliding amplitude is reduced, and the probability of fatigue crack initiation decreases.

[0081] Preferably, the front ends of both claws are designed as slightly upturned tongues. In the free state, the distance between the tongue ends is smaller than the thickness of the aluminum busbar, forming a pre-interference. The inner side of the tongue end is provided with a 30° guide angle, which facilitates the gradual opening when the aluminum busbar is inserted, avoiding scratching the aluminum surface.

[0082] In some embodiments, the upper edges of the two copper busbar panels are flush, meaning the two copper busbar panels are at the same height within the opening slot 6 area, forming a unified reference plane. When the aluminum busbar is connected to the copper busbar panels, this plane provides symmetrical and equal contact areas on the front and rear surfaces of the aluminum busbar, resulting in uniform current density distribution and Joule thermal symmetry. During thermal expansion, the sliding forces generated on the front and rear surfaces of the aluminum busbar are equal in magnitude and opposite in direction, with a combined sliding amplitude close to zero. This significantly reduces interfacial fretting wear and lowers the probability of fatigue crack initiation. Simultaneously, the balanced forces prevent the aluminum busbar from being twisted, ensuring stable connection posture and preventing resistance drift during long-term operation.

[0083] After the claw 1 extends from the side edge of the copper busbar panel, the upper edge of the claw 1 is lower than the upper edge of the copper busbar panel, for example, by 0.3–0.8 mm, forming a local height reduction zone on both sides of the opening slot 6. As a result, the upper edges of both sides of the opening slot 6 are unobstructed, and when the aluminum busbar is inserted, the outer wall of the copper busbar panel can elastically spring outward to a large displacement, significantly reducing the insertion resistance; at the same time, the recessed area also functions as an elastic hinge, allowing the copper busbar panel to slide freely at an angle during thermal expansion, avoiding root bending fatigue and maintaining locking force and electrical conductivity stability over a long period of time.

[0084] In some embodiments, the claw 1 and the copper busbar panel are provided with protrusions 2 on the side facing the opening slot 6. Exemplarily, the hemispherical protrusions 2 or tapered micro-protrusions 2 are formed by semi-punching or micro-drawing, with the sharp corners facing the aluminum busbar, and are arranged in a matrix or staggered manner. Preferably, the area of ​​the protrusion 2 remains in a bare copper state, while the remaining surface is still tin-plated, which is beneficial for soldering wetting and ensures the hardness of the protrusion 2.

[0085] When the aluminum busbar is connected to the copper busbar body 3, the protrusion 2 abuts against the aluminum busbar.

[0086] When the aluminum busbar is inserted, the tip of the protrusion 2 first contacts the aluminum surface, the contact area decreases sharply, and the local pressure increases, which is enough to pierce the natural oxide layer (such as Al2O3) on the surface of the aluminum busbar and expose fresh metal, thus eliminating the need for chemical cleaning before aluminum wire welding. At the same time, the protrusion 2 is elastically compressed, generating a rebound force and forming multi-point pre-compression, which increases the friction and pull-out force after the aluminum wire and copper busbar are clamped together, so that the aluminum busbar is mechanically locked before welding, preventing the aluminum wire from axially coming out of the opening groove 6.

[0087] In some embodiments, a boss 5 is provided on the inner surface of the copper busbar panel facing the opening slot 6. Specifically, a pair of rectangular bosses 5 can be formed by semi-punching or micro-drawing. The axial direction of the bosses 5 is perpendicular to the insertion and removal direction of the aluminum busbar. The edges of the bosses 5 are rounded. Alternatively, the bosses 5 are semi-cylindrical to avoid scratching the aluminum busbar.

[0088] Correspondingly, a slot 7 is punched or milled at the same position on the aluminum strip. The slot 7 can be a through slot or a blind slot, with the edge of the slot beveled to facilitate insertion and guidance.

[0089] When the aluminum busbar is connected to the copper busbar body 3, the aluminum busbar is pushed in along the opening slot 6. When the inclined surface at the front end of the boss 5 contacts the chamfer at the entrance of the slot 7, a component force is generated, causing the aluminum busbar to slightly spring upward, and the boss 5 slides into the slot 7. After it is in place, the corresponding surfaces of the boss 5 and the slot 7 contact each other, achieving mutual locking. The aluminum busbar elastically rebounds and resets, emitting a clicking self-locking sound. The insertion force increases, which can be used as a positioning signal for automatic pressing equipment.

[0090] As can be seen from the above, the boss 5 cooperates with the slot 7 on the aluminum wire to achieve mechanical locking, resist the insertion and extraction reaction force, and prevent the aluminum wire from axially (in the insertion and extraction direction) coming out in the opening slot 6.

[0091] In some embodiments, after the aluminum busbar is inserted into the opening slot 6, the inner surfaces of the copper busbar panels on both sides are not tightly attached to the aluminum busbar, and there is a gap between the copper busbar panel and the aluminum busbar, such as a uniform gap of 0.05–0.15 mm.

[0092] The copper busbar faceplate and / or baseplate are provided with a solder groove 4, which is used to inject solder into the gap between the copper busbar faceplate and the aluminum busbar. For example, during copper-aluminum brazing (e.g., tin-lead brazing, jet welding, etc.), the solder is introduced into the gap between the copper busbar and the aluminum busbar through the solder groove 4 to prevent defects such as cold solder joints, solder joint peeling, and inter-turn short circuits.

[0093] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0094] The connecting copper busbar provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model. Therefore, this utility model is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A connecting copper bar, characterized in that, include: A copper busbar body (3) is used to connect with an aluminum busbar; Two copper busbar panels are provided at the ends of the copper busbar body (3). The ends of the two copper busbar panels have opening slots (6), and there is a gap between the two copper busbar panels to form the slot width of the opening slots (6). Two sets of claws (1) are respectively provided on both sides of the copper busbar panel. The claws (1) extend from the side of one of the copper busbar panels and point to the other copper busbar panel. There is a gap between the claws (1) on both sides to form the groove length of the opening slot (6). When the aluminum busbar is connected to the copper busbar body (3), the aluminum busbar is inserted into the opening slot (6), the two sides of the aluminum busbar are welded to the two copper busbar panels respectively, and the two sides of the aluminum busbar are welded to the inner wall of the claw (1) respectively.

2. The connecting copper bar according to claim 1, characterized in that It also includes a base plate, which is located at the interface line between the copper busbar body (3) and the copper busbar panel. The base plate forms the bottom surface of the opening groove (6). When the aluminum busbar is connected to the copper busbar body (3), the bottom surface of the aluminum busbar contacts the base plate.

3. The connecting copper bar according to claim 2, characterized in that The middle part of the copper busbar body (3) is bent to form two sub-copper busbars. The two sub-copper busbars are attached together. The end of one sub-copper busbar extends outward to form a copper busbar panel, and the end of the other sub-copper busbar extends outward to form the base plate and the other copper busbar panel.

4. The connecting copper bar according to claim 1, characterized in that, The two sets of claws (1) extend from the same copper busbar panel, with the end of the claw (1) extending beyond the other copper busbar panel. After the aluminum busbar is connected to the copper busbar body (3), the portion of the end of the claw (1) extending beyond the other copper busbar panel is pressed against the other copper busbar panel.

5. The connecting copper bar according to claim 4, characterized in that After the portion of the claw (1) that extends beyond the other copper busbar panel presses against the copper busbar panel, the portions that extend on both sides are opposite each other and there is a gap between them; Alternatively, the portion of the end of one of the claws (1) that extends beyond the other copper busbar panel may cover the length of the opening slot (6).

6. The connecting copper bar according to claim 5, characterized in that The copper busbar panel has multiple claws (1) arranged vertically on both sides, and there is a gap between the claws (1) on the same side. The claws (1) on both sides are respectively placed at the gap on the opposite side.

7. The connecting copper bar according to claim 1, characterized in that Each set of the claws (1) includes a first claw body and a second claw body extending from the two copper busbar panels respectively. The ends of the first claw body and the second claw body are opposite to each other. After the aluminum busbar is connected to the copper busbar body (3), the first claw body and the second claw body are pressed against the aluminum busbar.

8. The connecting copper bar according to claim 1, characterized in that The upper edges of the two copper busbar panels are flush, and the upper edge of the claw (1) is lower than the upper edge of the copper busbar panels.

9. The connecting copper bar according to claim 1, characterized in that The claw (1) and the copper busbar panel are provided with protrusions (2) on the side facing the opening slot (6). When the aluminum busbar is connected to the copper busbar body (3), the protrusions (2) abut against the aluminum busbar.

10. The connecting copper bar according to claim 1, characterized in that The copper bar panel is provided with a boss (5), the direction of the boss (5) is perpendicular to the plug-in direction of the aluminum bar inserted into the opening slot (6), the aluminum bar is provided with a clamping groove (7), when the aluminum bar is connected with the copper bar body (3), the boss (5) is clamped with the clamping groove (7).

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