A welding structure and a welding method of a continuous tab and a bus bar

Abstract

The application discloses a kind of welding structure and welding method of continuous coating tab and busbar, comprising: mold, busbar forming groove is equipped on mold, the side of busbar forming groove is equipped with opening, the groove bottom of busbar forming groove is equipped with multiple first sockets arranged at intervals;Side baffle, it is arranged in the opening side of mold, side baffle and busbar forming groove are enclosed into the molding cavity with top open together;Terminal positioning groove;Preparation lead block, it is placed in molding cavity, the upper end surface of preparation lead block is alternately provided with groove and plane portion along its length direction, the second socket that is cooperated with tab is equipped at the lower end of plane portion;Wherein, preparation lead block is melted by heat source, to weld and fix the lower end of terminal with tab.The application can solve the problem that in prior art, when welding, lead block is synchronously melted to form continuous through molten pool, and flame continues directional blowing and pressing to cause molten lead liquid to be washed, leading to tab root being easily fused off, pulled off, and then causing the problems of insufficient connection reliability, false welding and virtual welding.

Description

Technical Field

[0001] This invention relates to the field of storage battery technology, specifically to a welding structure and welding method for a continuous coated tab and busbar. Background Technology

[0002] In the lead-acid battery manufacturing industry, continuously coated plates are widely used due to their high continuous production efficiency. However, their tab thickness is generally thin, with positive tabs typically 0.8–0.9 mm thick and negative tabs only 0.6–0.7 mm thick. In the busbar welding process, the traditional method often uses an oxy-acetylene flame to directly weld lead, where the welding torch melts lead and drips it onto the base of the tab to connect it to the busbar and terminals. However, due to the thin cross-section of the tab and the strong impact of the oxy-acetylene flame, the tab may melt and even be severed from its base during welding. Even if the solder appears to cover the tab after welding, excessive burning of the tab metal can result in a weak or false weld, and the connection is not reliably formed.

[0003] To improve the welding quality of thin electrode tabs, some processes use prefabricated lead blocks placed above the tabs before being melted by flame. However, existing prefabricated lead blocks are mostly rectangular blocks with uniform cross-sections, and the welding torch continuously welds along a straight trajectory during welding, resulting in highly concentrated and uninterrupted heat. Because the rectangular blocks have a uniform thickness throughout, they melt synchronously when heated, and the molten pool is in a continuous and unbroken state. The molten lead remains in a highly fluid state due to the continuous blowing and pressure of the flame, and the risk of the tab root being broken by impact is not effectively reduced. Summary of the Invention

[0004] Purpose of the invention: To provide a welding structure and welding method for a continuous coated tab and a busbar, aiming to solve the problems in the prior art where, during welding, the simultaneous melting of the lead block forms a continuous through-flow molten pool, and the continuous directional blowing of the flame causes the molten lead to be washed away, resulting in the tab root being easily melted and pulled off, thus causing incomplete welding, false welding and insufficient connection reliability.

[0005] Technical solution: A welded structure for continuous coating of electrode tabs and busbars, comprising: The mold has a busbar forming groove, an opening on one side of the busbar forming groove, and multiple spaced first insertion ports for inserting electrode tabs at the bottom of the busbar forming groove. A side baffle is detachably disposed on one side of the opening of the mold, and the side baffle and the busbar forming groove together form a forming cavity with an open top; A terminal positioning groove is formed on the mold and is used to position the lower end of the terminal in the busbar forming groove. A pre-made lead block is placed in the molding cavity. The upper end face of the pre-made lead block is alternately provided with grooves and flat surfaces along its length. The lower end of the flat surface is provided with a second insertion port that mates with the electrode tab. The prefabricated lead block is melted by a heat source to weld and fix the lower end of the terminal to the electrode tab.

[0006] A further improvement of the present invention is that the first socket is connected to the opening, and the connected end is provided with a flared opening to facilitate the insertion of the electrode tab from the side.

[0007] A further improvement of the present invention is that the side guard strip is provided with a boss that mates with the flared opening, which is used to abut into the flared opening when the side guard strip is installed in place, so as to prevent lead liquid leakage during welding.

[0008] A further improvement of the present invention is that the terminal includes a lead base and a copper core, the copper core is provided with an internal thread for connection with the outside, and one end of the lead base is provided with a welding part for welding and fixing to the prefabricated lead block.

[0009] A further improvement of the present invention is that the surface of the welding part that mates with the precast lead block is an inclined surface, and the inclination angle of the inclined surface is 15°~30°.

[0010] A further improvement of the present invention is that the second insertion port is a bayonet with a width that gradually narrows from bottom to top.

[0011] The present invention also provides a welding method for connecting coated tabs and busbars, used for welding the above-mentioned welding structure, comprising the following steps: S1: Insert the tab of the continuous coating plate into the first socket of the mold, and place the lower end of the terminal in the terminal positioning groove; S2: Install the side baffle to the opening side of the mold to form the molding cavity; S3: Place the precast lead block into the molding cavity, so that the second insertion port at its lower end mates with the upper end of the electrode tab; S4: Using an oxy-acetylene welding torch, welding is performed along the length of the upper end face of the precast lead block, and the welding torch is controlled to move back and forth between the groove and the flat part to form a wave-shaped welding trajectory with the peak corresponding to the flat part and the trough corresponding to the groove, so that the precast lead block is intermittently heated and melted, and the lower end of the terminal is welded together with the electrode tab.

[0012] A further improvement of the present invention is that, in the wavy welding trajectory, the height difference between the distance between the crest and the flat part and the distance between the trough and the bottom of the groove is 8~15mm.

[0013] A further improvement of the present invention is that, during the welding process, the melting state of the precast lead block is controlled by the wavy welding trajectory to reduce the fluidity of the molten lead, thereby preventing the molten lead from being blown away by the flame and breaking off the base of the electrode lug.

[0014] The beneficial effects of this invention are as follows: This invention features alternating grooves and planar surfaces along the length of the upper surface of a precast lead block, creating a structure with alternating thicknesses. During welding, different thermal contact distances achieve different degrees of melting, forming intermittent buffers in the molten pool. This effectively prevents the continuous flow of molten lead, avoiding the risk of the electrode root being eroded and broken due to a continuous molten pool, as seen in the prior art.

[0015] The terminal of this invention adopts a lead-based structure with a copper core. The copper core has internal threads for external connection, and one end of the lead base has a welding portion for welding and fixing to a pre-made lead block. Since the welding portion is made of lead, it and the pre-made lead block (also made of lead) are of the same metal, forming a strong metallurgical bond. The surface where the welding portion mates with the pre-made lead block is designed as a bevel. Compared to a perpendicular mating surface, the beveled structure guides the molten lead to flow and spread naturally along the bevel after the pre-made lead block melts, increasing the welding area between the terminal and the pre-made lead block, resulting in a stronger bond after cooling.

[0016] Compared to the shortcomings of the prior art where the welding torch continuously welds along a straight trajectory with highly concentrated and uninterrupted heat, this invention controls the welding torch to move back and forth between the groove and the flat part, forming a wave-shaped welding trajectory where the peaks correspond to the flat part and the troughs correspond to the grooves. When the welding torch moves to the flat part (peak), the flame distance is relatively far, mainly serving to preheat and slow melting; when the welding torch moves to the groove (trough), the flame distance is shortened, concentrating the heating of the groove area. This periodic undulation causes changes in the blowing direction and force of the flame, causing the precast lead block to melt intermittently, and the molten lead in the molten pool is in a dynamically controllable state, effectively reducing the problem of the thin electrode ear root being broken by impact. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the positional relationship between the electrode tab and the prefabricated lead block of the present invention.

[0018] Figure 2 This is a schematic diagram showing the positional relationship between the terminals and the mold of the present invention.

[0019] Figure 3 This is a top view of the structure of the present invention (the prefabricated lead block is not shown in the figure).

[0020] Figure 4 This is a side view sectional diagram of the structure of the present invention.

[0021] Figure 5This is a schematic diagram showing the positional relationship between the electrode tabs and terminals of the present invention.

[0022] Figure 6 This is a schematic front view of the structure of Embodiment 2 of the present invention (the side bars are not shown in the figure).

[0023] Figure 7 This is a side cross-sectional view of the structure of Embodiment 2 of the present invention.

[0024] Figure 8 This is a schematic diagram of the busbar structure after welding according to the present invention.

[0025] In the figure, 1-mold, 2-bus forming groove, 3-first socket, 4-side baffle, 5-terminal positioning groove, 6-terminal, 7-prefabricated lead block, 8-groove, 9-flat part, 10-second socket, 11-flared opening, 12-bore, 13-lead base, 14-copper core, 15-sloping surface, 16-oxygen-acetylene welding torch, 17-electrode. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. Example

[0029] Combination Figure 1-5 It is known that a welded structure for a continuous coated electrode lug and busbar includes: Mold 1, the mold 1 is provided with busbar forming groove 2, the side of the busbar forming groove 2 is provided with an opening, and the bottom of the busbar forming groove 2 is provided with multiple spaced first insertion ports 3 for the electrode tabs to be inserted. Side baffle 4 is detachably set on one side of the opening of mold 1. Side baffle 4 and busbar forming groove 2 together form a forming cavity with an open top. Terminal positioning groove 5 is formed on mold 1 and is used to position the lower end of terminal 6 in busbar forming groove 2; A pre-made lead block 7 is placed in the molding cavity. The upper end surface of the pre-made lead block 7 is alternately provided with grooves 8 and flat surfaces 9 along its length. The lower end of the flat surface 9 is provided with a second insertion port 10 that mates with the electrode tab. In this process, the prefabricated lead block 7 is melted by a heat source to weld and fix the lower end of the terminal 6 to the electrode tab.

[0030] The bottom of mold 1 is also provided with multiple positioning holes 20 for fixing mold 1 to the welding workbench. The side baffle 4 is made of heat-resistant steel and can abut against mold 1 through a push rod.

[0031] Terminal positioning groove 5 is located at one end of the busbar forming groove 2 in the width direction, and the bottom of terminal positioning groove 5 is connected to the bottom of busbar forming groove 2. The length of precast lead block 7 is adapted to the length of busbar forming groove 2, and the width of precast lead block 7 is adapted to the width of busbar forming groove 2.

[0032] The first insertion port 3 is connected to the opening, and the connected end is provided with a flared end 11 to facilitate the insertion of the electrode tab from the side. The side retainer 4 is provided with a boss 12 that mates with the flared end 11, which is used to abut into the flared end 11 when the side retainer 4 is installed in place to prevent lead liquid leakage during welding.

[0033] Preferably, the opening angle of the flare 11 is 30°~60°. The shape of the boss 12 is adapted to the shape of the flare 11, and it abuts into the first insertion port 3 and abuts against the side wall of the electrode lug.

[0034] In this embodiment, terminal 6 includes a lead base 13 and a copper core 14. The copper core 14 has internal threads for external connection, and one end of the lead base 13 has a welding part for welding and fixing to the prefabricated lead block 7. The copper core 14 and the lead base 13 are fixedly connected as one piece by casting.

[0035] The surface of the welded part that mates with the precast lead block 7 is an inclined surface 15, with an inclination angle of 15° to 30°. The inclined surface 15 slopes upward from bottom to top in a direction away from the precast lead block 7.

[0036] Preferably, the second insertion port 10 is a bayonet that gradually narrows in width from bottom to top. More preferably, the lower end face of the precast lead block 7, located at the opening edge of the second insertion port 10, is provided with a rounded chamfer with a radius of 0.5~1.0mm, which is used to form a rounded transition at the root of the electrode lug after the precast lead block 7 is melted.

[0037] Preferably, both the mold 1 and the side baffle 4 are made of heat-resistant cast iron or mold steel, with a surface roughness Ra≤1.6μm to prevent molten lead from adhering. After welding, the molten lead in the forming cavity cools and solidifies naturally to form the manifold body. The inner wall of the manifold forming groove 2 is provided with a draft angle (1°~3°) to facilitate smooth demolding of the manifold after welding. Example

[0038] See Figure 6-8 A welding method for connecting coated tabs and busbars, used to weld the welding structure of Example 1, includes the following steps: S1: Insert the tabs of the continuous coating plate into the first insertion port 3 of the mold 1, and place the lower end of the terminal 6 in the terminal positioning groove 5; specifically, push the continuous coating plate in from the side in the horizontal direction, so that each tab enters the first insertion port 3 through the corresponding flared port 11, until the upper end of the tab extends above the bottom of the busbar forming groove 2.

[0039] S2: Install the side baffle 4 onto the opening side of the mold 1 to form a molding cavity; specifically, place the side baffle 4 on the opening side of the mold 1, so that the boss 12 on the side baffle 4 is aligned and abuts into the corresponding flared opening 11 and abuts against the side wall of the electrode tab, so that the boss 12 seals the connection between the flared opening 11 and the opening to prevent lead liquid from leaking during welding.

[0040] S3: Place the pre-made lead block 7 into the molding cavity, so that the second insertion port 10 at its lower end mates with the upper end of the electrode tab; specifically, place the pre-made lead block 7 into the molding cavity from top to bottom, so that the upper end of each electrode tab is inserted into the corresponding second insertion port 10.

[0041] S4: Using an oxyacetylene torch 16, welding is performed along the length of the upper end face of the precast lead block 7, and the torch is controlled to move back and forth between the groove 8 and the flat part 9 to form a wave-shaped welding trajectory with the peak corresponding to the flat part 9 and the trough corresponding to the groove 8, so that the precast lead block 7 is intermittently heated and melted, and the lower end of the terminal 6 is welded together with the electrode tab.

[0042] Preferably, when the welding torch 16 moves above the flat section 9, it is at the crest position, with the distance between the outer flame of the welding torch 16 and the upper surface of the flat section 9 being 15~25mm, and the dwell time being 1.5~2.5s, preheating and slowing the melting of the flat section 9; when the welding torch 16 moves above the groove 8, it is at the trough position, with the distance between the outer flame of the welding torch 16 and the bottom of the groove 8 being 5~10mm, and the dwell time being 0.5-1.0s, concentrating the heating of the groove 8. During the movement of the welding torch 16, the moving speed of the welding torch 16 remains uniform.

[0043] Preferably, in the wavy welding trajectory, the height difference between the distance between the crest and the flat part 9 and the distance between the trough and the bottom of the groove 8 is 8~15mm. During the welding process, the melting state of the precast lead block 7 is controlled by the wavy welding trajectory to reduce the fluidity of the molten lead, thereby preventing the molten lead from being blown away by the flame and breaking off the root of the electrode lug.

[0044] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A welded structure for a continuous coated electrode lug and a busbar, characterized in that, include: The mold (1) is provided with a busbar forming groove (2), and an opening is provided on one side of the busbar forming groove (2). The bottom of the busbar forming groove (2) is provided with multiple spaced first insertion ports (3) for the insertion of the electrode tabs. Side baffle (4) is detachably provided on one side of the opening of the mold (1), and the side baffle (4) together with the busbar forming groove (2) form a top-open forming cavity; Terminal positioning groove (5) is provided on the mold (1) to position the lower end of the terminal (6) in the busbar forming groove (2); A pre-made lead block (7) is placed in the molding cavity. The upper end surface of the pre-made lead block (7) is alternately provided with grooves (8) and flat surfaces (9) along its length direction. The lower end of the flat surface (9) is provided with a second insertion port (10) that cooperates with the electrode tab. The precast lead block (7) is melted by a heat source to weld and fix the lower end of the terminal (6) to the electrode tab.

2. The welding structure of the continuous coated electrode lug and busbar according to claim 1, characterized in that: The first insertion port (3) is connected to the opening, and the connecting end is provided with a flared opening (11) to facilitate the insertion of the electrode from the side.

3. The welding structure of the continuous coated electrode lug and busbar according to claim 2, characterized in that: The side baffle (4) is provided with a boss (12) that cooperates with the flared opening (11), which is used to abut into the flared opening (11) when the side baffle (4) is installed in place, so as to prevent lead liquid from leaking during welding.

4. The welding structure of the continuous coated electrode lug and busbar according to claim 1, characterized in that: The terminal (6) includes a lead base (13) and a copper core (14). The copper core (14) is provided with an internal thread for connection to the outside. One end of the lead base (13) is provided with a welding part for welding and fixing to the precast lead block (7).

5. The welding structure of the continuous coated electrode lug and busbar according to claim 1, characterized in that: The surface of the welding part that mates with the precast lead block (7) is an inclined surface (15), and the inclination angle of the inclined surface (15) is 15°~30°.

6. The welding structure of the continuous coated electrode lug and busbar according to claim 1, characterized in that: The second slot (10) is a bayonet that gradually narrows in width from bottom to top.

7. A welding method for continuous coated tabs and busbars, used for welding the welding structure according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Insert the tab of the continuous coating plate into the first socket (3) of the mold (1) and place the lower end of the terminal (6) in the terminal positioning groove (5); S2: Install the side baffle (4) onto the opening side of the mold (1) to form the molding cavity; S3: Place the precast lead block (7) into the molding cavity, so that the second insertion port (10) at its lower end matches the upper end of the electrode tab; S4: Using an oxyacetylene torch (16), welding is performed along the length of the upper end face of the precast lead block (7), and the torch is controlled to move back and forth between the groove (8) and the flat part (9) to form a wave-shaped welding trajectory with the peak corresponding to the flat part (9) and the trough corresponding to the groove (8), so that the precast lead block (7) is intermittently heated and melted, and the lower end of the terminal (6) is welded together with the tab.

8. The welding method according to claim 7, characterized in that: In the wavy welding trajectory, the height difference between the distance between the crest and the flat part (9) and the distance between the trough and the bottom of the groove (8) is 8~15mm.

9. The welding method according to claim 7, characterized in that: During the welding process, the melting state of the precast lead block (7) is controlled by the wavy welding trajectory to reduce the fluidity of the molten lead and thus prevent the lead from being blown away by the flame and breaking off the base of the electrode lug.

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