Cylindrical lithium battery spot welding equipment and spot welding method thereof
By designing contact switches, clamping plates, and conversion mechanisms, the problem of inaccurate positioning of lithium battery clusters was solved, enabling precise welding and efficient testing, and improving the welding quality and equipment flexibility of lithium battery spot welding equipment.
Patent Information
- Application Number
- CN202511487640.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-17
- Publication Date
- 2025-12-23
AI Technical Summary
Existing lithium battery spot welding equipment lacks a precise positioning and triggering mechanism, resulting in inaccurate positioning of lithium battery clusters. The welding head is prone to deviating from the center of the tab, leading to excessive resistance at the weld point, severe localized heating, reduced cluster cycle life, and potential welding failure.
The combination design of contact switches and clamping plates ensures the vertical positioning of the lithium battery clusters. The clamping plates and conversion mechanism maintain the optimal energy interaction distance between the welding head and the tabs, dynamically adjusting to adapt to height changes. Combined with the detection mechanism, welding defects are identified in real time.
It achieves precise positioning and stable welding of lithium battery clusters, avoids the phenomenon of weld points deviating from the center of the tabs, ensures consistent welding energy density, improves welding quality and equipment flexibility, and reduces downtime for model changeover.
Smart Images
Figure CN121179094A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium battery spot welding technology, specifically to a cylindrical lithium battery spot welding device and its spot welding method. Background Technology
[0002] With the rapid development of the new energy industry, cylindrical lithium batteries are widely used in energy storage systems, electric vehicles, and portable electronic devices due to their advantages such as high energy density and structural stability. In practical applications, cylindrical lithium batteries are usually connected in series or parallel to form lithium battery clusters to meet the voltage and capacity requirements of different scenarios. Spot welding technology is the core process for connecting the electrode tabs of the lithium battery cluster to the series metal plates. Its welding precision, stability, and testing efficiency directly determine the electrical performance, cycle life, and safety of the lithium battery cluster.
[0003] Existing equipment often uses simple clamps to limit the position of lithium battery clusters, lacking a precise positioning triggering mechanism. This can easily lead to tilting or misalignment of the lithium battery clusters. If the positioning is inaccurate, the welding head may deviate from the center of the tab, resulting in excessively high solder joint resistance, severe localized heating during charging and discharging, creating a bottleneck effect, and significantly reducing the cycle life of the entire cluster. Summary of the Invention
[0004] To overcome the above deficiencies, the present invention provides a cylindrical lithium battery spot welding device that overcomes or at least partially solves the above technical problems.
[0005] This invention is implemented as follows: This invention provides a cylindrical lithium battery spot welding device, including a platform, with a spot welding mechanism installed on the top of the platform, the spot welding mechanism comprising: The first electric slide rail is fixedly installed on both sides of the platform. A support frame is slidably installed inside the first electric slide rail, and a second electric slide rail is provided between the support frames. The first sliding block is slidably installed inside the second electric slide rail, and a fixing bracket is fixedly installed at the bottom of the first sliding block; A welding assembly is disposed on the side of a fixed frame, and the welding assembly includes a first sliding rail, which is fixedly installed on the bottom of the fixed frame; The mounting component is slidably mounted inside the first sliding track, and a welding head is fixedly mounted on the side of the mounting component.
[0006] In one embodiment of the present invention, the spot welding mechanism further includes a fixing plate, which is fixedly installed on the top of the platform. Two fixing plates are provided. A clamping plate is slidably installed on the top of the platform. Two clamping plates are provided. A first spring is provided between the clamping plate and the fixing plate. Two first springs are provided. A first limiting rod is fixedly installed on the side of the clamping plate. The first limiting rod passes through the side of the fixing plate and is slidably connected to the fixing plate. A lithium battery cluster is provided between the two clamping plates. A positioning plate is fixedly installed on the top of the platform. A contact switch is fixedly installed on the side of the positioning plate.
[0007] In one embodiment of the present invention, the welding assembly further includes a first mounting base, which is fixedly mounted on the bottom of the mounting component. Two first mounting bases are provided, and a first threaded rod is rotatably mounted inside each of the two first mounting bases. A clamping piece is fixedly mounted at one end of the first threaded rod, and a first limiting plate is fixedly mounted at the other end of the first threaded rod.
[0008] In one embodiment of the present invention, a second limiting rod is fixedly installed on the side of the first limiting plate, the second limiting rod is slidably connected to the first mounting base, a first toothed plate is fixedly installed on the side of the fixing frame, a first gear is rotatably installed on the side of the first mounting base, the first gear is threadedly connected to the first threaded rod, and the first gear meshes with the first toothed plate.
[0009] In one embodiment of the present invention, the fixing frame is provided with a conversion mechanism, the conversion mechanism includes a mounting groove, the mounting groove is opened inside the fixing frame, a telescopic rod is fixedly installed on the top of the inner cavity of the mounting groove, two telescopic rods are provided, and a mounting plate is fixedly installed on the end of the telescopic rod.
[0010] In one embodiment of the present invention, a first motor is fixedly installed at the top of the inner cavity of the mounting groove, a second threaded rod is fixedly installed at the output end of the first motor, the second threaded rod is rotatably connected to the bottom of the inner cavity of the mounting groove, the second threaded rod is threadedly connected to the mounting plate, and a height sensor is fixedly installed on the side of the first sliding block, the height sensor being connected to the first motor via an electrical signal.
[0011] In one embodiment of the present invention, a side plate is fixedly mounted on the side of the mounting plate, a first bevel gear is rotatably mounted on the side of the side plate, and a second bevel gear is rotatably mounted on the top of the mounting plate. The first bevel gear meshes with the second bevel gear. A second motor is fixedly mounted on the top of the inner cavity of the mounting groove. A rack is fixedly mounted on the output end of the second motor, and the rack meshes with the second bevel gear. A rotating disk is fixedly mounted on the side of the first bevel gear, and a rotating plate is rotatably mounted on the eccentric part of the rotating disk. A connecting rod is rotatably mounted on the end of the rotating plate. A connecting frame is fixedly mounted on the side of the connecting rod, and the connecting frame is fixedly connected to the mounting component. A detection mechanism is fixedly mounted on the side of the connecting frame.
[0012] In one embodiment of the present invention, the detection mechanism includes a second mounting base, which is fixedly mounted on the side of the connecting frame. A second gear is rotatably mounted on the side of the second mounting base. A second toothed plate is fixedly mounted on the side of the fixed frame. The second gear meshes with the second toothed plate. A third threaded rod is installed on the internal thread of the second gear. A movable plate is fixedly mounted on the end of the third threaded rod.
[0013] In one embodiment of the present invention, a slide rod is slidably installed inside the movable plate, a fixing groove is formed on the surface of the second mounting base, a second spring is disposed inside the fixing groove, one end of the second spring is fixedly connected to the movable plate, a push plate is fixedly installed at the other end of the second spring, a guide rod is fixedly installed on the side of the push plate, the guide rod is slidably connected to the second mounting base, an electromagnet is disposed on the side of the push plate, and a control panel is fixedly installed on the side of the platform. The control panel is connected to the electromagnet and the second motor via an electrical signal.
[0014] A method for spot welding cylindrical lithium batteries, applicable to a cylindrical lithium battery spot welding device, comprises the following steps: S1: In the initial stage of the device, the electromagnet is energized by the control panel, so that the push plate is in contact with the second mounting base, and the initial state setting of the device is completed. S2: Drive the connecting frame to move downwards, and the connecting frame drives the third threaded rod to move synchronously, thereby causing the movable plate to compress the second spring, so that the second spring generates a rebound force and stores it; S3: After the welding head completes the welding work of the current weld point, the control panel receives the welding completion signal and controls the electromagnet to cut off the power. S4: After the electromagnet is de-energized, it loses its attraction to the push plate. At this time, the second spring releases the stored rebound force, pushing the push plate to quickly impact and push the previous welding point. S5: Observe the state of the metal ear after the pusher plate impacts and pushes it: If the metal ear becomes loose, shifts or even falls off, it indicates that the solder joint has defects such as poor soldering, cold soldering or solder joint cracking. It should be identified as a defective product on the spot to prevent it from entering subsequent processes such as assembly and packaging; if the metal ear is stable, the solder joint is qualified.
[0015] The present invention provides a cylindrical lithium battery spot welding device, the beneficial effects of which include: 1. This invention, through the setting of contact switches, ensures that the entire device only operates when the lithium battery cluster is perpendicular to the positioning plate. This allows the lithium battery cluster to be accurately positioned for welding. Furthermore, the two clamping plates ensure the stability of the lithium battery cluster, preventing displacement during welding. If the positioning is inaccurate, some weld points may deviate from the center of the tabs, resulting in excessive resistance at those weld points, severe localized heating during charging and discharging, creating a bottleneck effect, and reducing the cycle life of the entire cluster. If the cluster is not fixed stably, the impact force during welding may cause micro-displacement of the cells, resulting in deviations in the spacing between adjacent weld points. This leads to uneven stress on the tabs during subsequent assembly and makes the weld points prone to fatigue fracture after long-term use.
[0016] 2. The present invention, through the setting of the welding components, enables two clamping plates to clamp the series metal plates. The series metal plates need to cover the tabs of two adjacent cells at the same time. If the metal plates are offset, the welding point may deviate from the center of the tabs and only be welded to the edge of the metal plate, resulting in insufficient conductive area. Alternatively, the metal plate may cover the cell shell and mis-weld the insulation area, resulting in an open circuit. The clamping plates can firmly fix the metal plates in the preset position, ensuring that the connection area of the metal plate is completely overlapped with the two tabs, thus avoiding welding failure caused by metal plate displacement from the source.
[0017] 3. This invention, through the setting of the conversion mechanism, ensures that the distance between the welding head and the lithium battery cluster remains constant. When the distance is dynamically adjusted with height, it can always maintain the optimal energy interaction distance between the welding head and the tab, ensuring that the energy density of each weld is consistent, and the weld penetration and strength are uniform. This fundamentally avoids welding defects caused by height differences. The dynamic adjustment mechanism can automatically adapt to height changes through mechanical linkage without manual intervention, making the same equipment compatible with clusters of all sizes from low to high, greatly improving equipment flexibility and reducing downtime for model changeovers. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the overall structure provided by an embodiment of the present invention; Figure 2 A schematic diagram of the overall platform top structure is provided for embodiments of the present invention; Figure 3 A schematic diagram of the welding assembly structure provided for an embodiment of the present invention; Figure 4 A rear view diagram of the welding assembly provided for an embodiment of the present invention; Figure 5 A schematic diagram of the first mounting base structure provided for an embodiment of the present invention; Figure 6 A schematic diagram of the second mounting base structure provided for an embodiment of the present invention; Figure 7 A schematic diagram of the conversion mechanism structure provided for an embodiment of the present invention; Figure 8 Provided for the embodiments of the present invention Figure 6 Enlarged structural diagram of section A in the middle.
[0020] In the diagram: 1. Platform; 2. Spot welding mechanism; 201. First electric slide rail; 202. Second electric slide rail; 203. First sliding block; 204. Fixing frame; 205. Fixing plate; 206. Clamping plate; 207. First spring; 208. First limiting rod; 209. Lithium battery cluster; 210. Positioning plate; 211. Contact switch; 212. Support frame; 3. Welding assembly; 301. First sliding rail; 302. Mounting component; 303. Welding head; 304. First mounting base; 305. First threaded rod; 306. Clamping piece; 307. First limiting plate; 308. Second limiting rod; 309. First toothed plate; 310. First gear; 4. Conversion mechanism; 40 1. Mounting slot; 402. Telescopic rod; 403. Mounting plate; 404. First motor; 405. Second threaded rod; 406. Height sensor; 407. Side plate; 408. First bevel gear; 409. Second bevel gear; 410. Second motor; 411. Gear rack; 412. Rotating disk; 413. Rotating plate; 414. Connecting rod; 415. Connecting frame; 5. Detection mechanism; 501. Second mounting base; 502. Second gear; 503. Second gear plate; 504. Third threaded rod; 505. Movable plate; 506. Slide rod; 507. Fixed slot; 508. Second spring; 509. Push plate; 510. Guide rod; 511. Electromagnet; 512. Control panel. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] Reference Figures 1-8This technical solution provides a cylindrical lithium battery spot welding device, specifically including a platform 1. A spot welding mechanism 2 is installed on the top of the platform 1. The spot welding mechanism 2 includes a first electric slide rail 201, a first sliding block 203, a welding assembly 3, and a mounting component 302. The first electric slide rail 201 is fixedly installed on both sides of the platform 1. A support frame 212 is slidably installed inside the first electric slide rail 201, and the support frame 212 can slide inside the first electric slide rail 201. A second electric slide rail 202 is arranged between the support frames 212. The first sliding block 203 is slidably installed inside the second electric slide rail 202, and the first sliding block 203 can slide inside the second electric slide rail 202. The first electric slide rail 201 and the second electric slide rail 202 are connected by the first electric slide rail 201 and the second electric slide rail 202. The 02 setting allows the entire welding assembly 3 to move longitudinally and laterally. A fixing frame 204 is fixedly installed at the bottom of the first sliding block 203. The welding assembly 3 is located on the side of the fixing frame 204. The welding assembly 3 includes a first sliding track 301, which is fixedly installed at the bottom of the fixing frame 204. A mounting piece 302 is slidably installed inside the first sliding track 301. A welding head 303 is fixedly installed on the side of the mounting piece 302. The mounting piece 302 can slide up and down inside the first sliding track 301. When the mounting piece 302 slides up and down, the welding head 303 can weld the end of the lithium battery. The spot welding mechanism 2 also includes a fixing plate 205, which is fixedly installed on the platform 1. At the top, two fixed plates 205 are provided. Two clamping plates 206 are slidably installed on the top of platform 1. A first spring 207 is provided between the clamping plates 206 and the fixed plates 205. A first limiting rod 208 is fixedly installed on the side of the clamping plates 206, extending through to the side of the fixed plates 205 and slidably connected to them. A lithium battery cluster 209 is provided between the two clamping plates 206. A positioning plate 210 is fixedly installed on the top of platform 1, and a contact switch 211 is fixedly installed on the side of the positioning plate 210. During welding, the worker pushes the lithium battery cluster 209 between the two clamping plates 206. Under the pressure of the lithium battery cluster 209, the lithium battery cluster 209... The two clamping plates 206 are moved away from each other. Simultaneously, the first spring 207 is compressed, causing it to rebound. This rebound force is applied to the two clamping plates 206, thus clamping the lithium battery cluster 209. When the lithium battery cluster 209 moves to the positioning plate 210, its ends contact the contact switches 211. Multiple contact switches 211 are provided, controlling the operation of the entire device. When the lithium battery cluster 209 simultaneously contacts the contact switches 211, it indicates that the lithium battery cluster 209 has not shifted, and the welding head 303 can be precisely aligned with the lithium battery cluster 209, preventing errors during welding.The entire device is powered on and running. However, if not all of the multiple contact switches 211 are triggered, it indicates that the lithium battery cluster 209 is not perpendicular to the positioning plate 210, and the lithium battery cluster 209 has shifted. At this time, the entire device is powered off, and welding will not occur regardless of the operator's actions. The contact switches 211 ensure that the entire device only operates when the lithium battery cluster 209 is perpendicular to the positioning plate 210, allowing the lithium battery cluster 209 to be precisely positioned for welding. Furthermore, the two clamping plates 206 ensure the stability of the lithium battery cluster 209, preventing displacement during welding. Inaccurate positioning may cause some weld points to deviate from the center of the tabs, resulting in excessive resistance at those weld points, severe localized heating during charging and discharging, creating a bottleneck effect, and reducing the cycle life of the entire cluster. If the cluster is not securely fixed, the impact force during welding may cause micro-displacement of the cells, leading to deviations in the spacing between adjacent weld points. This results in uneven stress on the tabs during subsequent assembly, and long-term fatigue fracture of the weld points is likely to occur.
[0023] Reference Figures 1-8 This embodiment also proposes that the welding assembly 3 further includes a first mounting base 304, which is fixedly installed on the bottom of the mounting component 302. Two first mounting bases 304 are provided, and a first threaded rod 305 is rotatably mounted inside each of the two first mounting bases 304. A clamping piece 306 is fixedly mounted at one end of the first threaded rod 305, and a first limiting plate 307 is fixedly mounted at the other end of the first threaded rod 305. A second limiting rod 308 is fixedly mounted on the side of the first limiting plate 307 and is slidably connected to the first mounting base 304. A first toothed plate 309 is fixedly mounted on the side of the fixing frame 204, and a first gear 310 is rotatably mounted on the side of the first mounting base 304. The first gear 310 is threadedly connected to the first threaded rod 305, and meshes with the first toothed plate 309. When the mounting component 302 moves downwards, it can drive the first mounting base 304 to move upwards as well. The downward movement of the first mounting base 304 drives the first gear 310 downward, thereby linking the first gear 310 with the first gear plate 309, causing the first gear 310 to rotate. When the first gear 310 rotates, it drives the first threaded rod 305 to move inside the first gear 310, thereby pushing the clamping plates 306 to move. The movement of the two clamping plates 306 can clamp the series metal plates. The series metal plates need to cover the tabs of two adjacent cells at the same time. If the metal plates are offset, the welding point may deviate from the center of the tab and only be welded to the edge of the metal plate, resulting in insufficient conductive area. Alternatively, the metal plate may cover the cell shell and mis-weld the insulation area, resulting in an open circuit. The clamping plates 306 can firmly fix the metal plates in the preset position, ensuring that the connection area of the metal plate is completely overlapped with the two tabs, thus avoiding welding failure caused by the displacement of the metal plates from the source.
[0024] reference Figures 1-8This embodiment also proposes that the fixing frame 204 is internally provided with a conversion mechanism 4. The conversion mechanism 4 includes a mounting groove 401, which is opened inside the fixing frame 204. A telescopic rod 402 is fixedly installed at the top of the inner cavity of the mounting groove 401. Two telescopic rods 402 are provided. A mounting plate 403 is fixedly installed at the end of the telescopic rod 402. A first motor 404 is fixedly installed at the top of the inner cavity of the mounting groove 401. A second threaded rod 405 is fixedly installed at the output end of the first motor 404. The first motor 404 can drive the second threaded rod 405 to rotate. The second threaded rod 405 is rotatably connected to the bottom of the inner cavity of the mounting groove 401. The second threaded rod 405 is threadedly connected to the mounting plate 403. When the second threaded rod 405 rotates... When the motor rotates, it can drive the mounting plate 403 to move up and down. A height sensor 406 is fixedly installed on the side of the first sliding block 203. The height sensor 406 is connected to the first motor 404 via an electrical signal. The height sensor 406 can measure the height of the lithium battery cluster 209 and cause the first motor 404 to rotate according to the height. A side plate 407 is fixedly installed on the side of the mounting plate 403. A first bevel gear 408 is rotatably installed on the side of the side plate 407. A second bevel gear 409 is rotatably installed on the top of the mounting plate 403. The first bevel gear 408 and the second bevel gear 409 mesh with each other. A second motor 410 is fixedly installed on the top of the inner cavity of the mounting groove 401. The output end of the second motor 410 is fixedly installed. A rack 411 is fixedly installed, meshing with a second bevel gear 409. A rotating disk 412 is fixedly installed on the side of the first bevel gear 408. A rotating plate 413 is rotatably installed at the eccentric part of the rotating disk 412. A connecting rod 414 is rotatably installed at the end of the rotating plate 413. A connecting frame 415 is fixedly installed on the side of the connecting rod 414. The connecting frame 415 is fixedly connected to the mounting part 302. A detection mechanism 5 is fixedly installed on the side of the connecting frame 415. When the first motor 404 starts, it can drive the second threaded rod 405 to rotate. The rotation of the second threaded rod 405 can drive the mounting plate 403 to move up and down. The up and down movement of the mounting plate 403 can drive the first bevel gear 408, the second bevel gear 409, and... The rotating disk 412 moves downwards together with the rotating disk 412, which also allows the mounting part 302 to move downwards inside the first sliding track 301. Simultaneously, during the welding process, the second motor 410 remains running. The second motor 410 drives the rack 411 to rotate. The rack 411 is slidably connected to the second bevel gear 409, and the rack 411 and the second bevel gear 409 mesh internally. Therefore, the rotation of the rack 411 drives the second bevel gear 409 to rotate, which in turn drives the first bevel gear 408 to rotate. The rotation of the first bevel gear 408 drives the rotating disk 412 to rotate, and the rotation of the rotating disk 412 drives the rotating plate 413 to rotate eccentrically.The eccentric rotation of the rotating plate 413 can drive the connecting rod 414 to move up and down, which in turn drives the connecting frame 415 to move up and down, and in turn drives the mounting part 302 and the welding head 303 to move up and down. When the first motor 404 rotates, the initial height of the mounting part 302 inside the first sliding track 301 changes. Therefore, when the second motor 410 starts, the bottom of the welding head 303 will change. When the lithium battery cluster 209 is at a higher height, the first motor 404 drives the mounting plate 403 to move upward, so that the bottom of the welding head 303 is at a higher position. When the lithium battery cluster 209 is at a higher height, the first motor 404 drives the mounting plate 403 to move upward, so that the bottom of the welding head 303 is at a higher position. When the height of 209 is low, the lowest point of welding head 303 is in a low position. Through the setting of conversion mechanism 4, the distance between welding head 303 and lithium battery cluster 209 remains constant. When the distance is dynamically adjusted with height, the optimal energy interaction distance between welding head 303 and the electrode tab is always maintained, ensuring consistent energy density, uniform weld penetration and strength for each weld. This fundamentally avoids welding defects caused by height differences. The dynamic adjustment mechanism automatically adapts to height changes through mechanical linkage without manual intervention, allowing the same equipment to be compatible with clusters of all sizes from low to high, significantly improving equipment flexibility and reducing downtime for model changes.
[0025] Reference Figures 1-8This embodiment also proposes a detection mechanism 5 including a second mounting base 501, which is fixedly mounted on the side of the connecting frame 415. A second gear 502 is rotatably mounted on the side of the second mounting base 501, and a second toothed plate 503 is fixedly mounted on the side of the fixing frame 204. The second gear 502 meshes with the second toothed plate 503. When the connecting frame 415 moves up and down, it can drive the second gear 502 to move up and down, thereby causing the second gear 502 to rotate. A third threaded rod 504 is installed on the internal thread of the second gear 502. A movable plate 505 is fixedly installed at the end. The rotation of the second gear 502 can drive the third threaded rod 504 to move inside the second gear 502. A slide rod 506 is slidably installed inside the movable plate 505. A fixing groove 507 is opened on the surface of the second mounting base 501. A second spring 508 is installed inside the fixing groove 507. One end of the second spring 508 is fixedly connected to the movable plate 505. A push plate 509 is fixedly installed at the other end of the second spring 508. A guide rod 510 is fixedly installed on the side of the push plate 509. The guide rod 510 is slidably connected to the second mounting base 501. An electromagnet 511 is installed on the side of platform 1, and a control panel 512 is fixedly installed on the side of platform 1. The control panel 512 is connected to the electromagnet 511 and the second motor 410 via an electrical signal. In the initial stage, the electromagnet 511 is energized, causing the push plate 509 to fit against the second mounting base 501. At this time, when the connecting bracket 415 moves downward, it drives the third threaded rod 504 to move, causing the movable plate 505 to compress the second spring 508, causing the second spring 508 to generate a rebound force. The control panel 512 controls the electromagnet 511 to move when the welding head 303 is completed. Power is cut off. Therefore, when the welding head 303 finishes welding the next weld point, the electromagnet 511 is de-energized. Under the action of the rebound force of the second spring 508, the push plate 509 quickly impacts and pushes the previous weld point. Welding defects such as false welding, cold welding, and weld point cracking often have no abnormal appearance but insufficient internal bonding force. They are difficult to detect by visual inspection alone. When pushing the metal ear, the external force is directly applied to the connection between the welding point and the metal ear. If the welding is not firm, the metal ear will directly become loose, shift, or even fall off. Defective products can be identified on the spot to prevent them from entering subsequent processes such as assembly and packaging.
[0026] Reference Figures 1-8 This embodiment also proposes a spot welding method for cylindrical lithium batteries, applicable to a cylindrical lithium battery spot welding device, the steps of which are as follows: S1: In the initial stage of the device, the electromagnet 511 is energized by the control panel 512, so that the push plate 509 is in contact with the second mounting base 501, and the initial state setting of the device is completed. S2: Drive the connecting frame 415 to move downward, and the connecting frame 415 drives the third threaded rod 504 to move synchronously, thereby causing the movable plate 505 to compress the second spring 508, so that the second spring 508 generates a rebound force and stores it. S3: After the welding head 303 completes the welding work of the current weld point, the control panel 512 receives the welding completion signal and controls the electromagnet 511 to perform a power-off operation. S4: After the electromagnet 511 is de-energized, it loses its attraction to the push plate 509. At this time, the second spring 508 releases the stored rebound force, pushing the push plate 509 to quickly impact and push the previous welding point. S5: Observe the state of the metal ear after the pusher plate 509 impacts and pushes it: If the metal ear becomes loose, shifts or even falls off, it indicates that the solder joint has defects such as poor soldering, cold soldering or solder joint cracking. It should be identified as a defective product on the spot to prevent it from entering subsequent processes such as assembly and packaging; if the metal ear is stable, the solder joint is qualified.
[0027] Specifically, the working process or principle of this cylindrical lithium battery spot welding equipment is as follows: the support frame 212 can slide inside the first electric slide rail 201, and the first sliding block 203 can slide inside the second electric slide rail 202. Through the arrangement of the first and second electric slide rails 201 and 202, the entire welding assembly 3 can be moved longitudinally and laterally. The mounting part 302 can slide up and down inside the first slide rail 301. When the mounting part 302 slides up and down, the welding head 303 can weld the end of the lithium battery. During welding, the operator applies the lithium... The battery cluster 209 is pushed between the two clamping plates 206. Under the pressure of the lithium battery cluster 209, the two clamping plates 206 move away from each other. Simultaneously, the two clamping plates 206 are compressed, causing the first spring 207 to generate a rebound force. This rebound force is applied to the two clamping plates 206, thus clamping the lithium battery cluster 209. When the lithium battery cluster 209 moves to the positioning plate 210, the end of the lithium battery cluster 209 contacts the contact switch 211. Multiple contact switches 211 are provided, and the contact switches 211 control the operation of the entire device. When the lithium battery cluster 209 can simultaneously contact the contact switch 211, it means that the lithium battery cluster 209 has not shifted, and the welding head 303 can accurately align the lithium battery cluster 209, so that no error occurs during welding, and the entire device is powered on and running. However, if multiple contact switches 211 are not all triggered, it means that the lithium battery cluster 209 is not perpendicular to the positioning plate 210, and the lithium battery cluster 209 has shifted. At this time, the entire device is powered off, and welding will not be performed regardless of the operator's operation. Through the setting of the contact switch 211, the entire device ensures that welding only occurs when the lithium battery cluster 209 is perpendicular to the positioning plate 210. The 210 operates only when vertical, allowing the lithium battery cluster 209 to be precisely positioned for welding. The two clamping plates 206 ensure the stability of the lithium battery cluster 209, preventing displacement during welding. Inaccurate positioning can cause some weld points to deviate from the center of the tabs, resulting in excessive resistance at those weld points, severe localized heating during charging and discharging, creating a bottleneck effect, and reducing the cycle life of the entire cluster. If the cluster is not stable, the impact force during welding may cause micro-displacement of the cells, leading to deviations in the spacing between adjacent weld points. This results in uneven stress on the tabs during subsequent assembly, and long-term fatigue fracture of the weld points is likely to occur.
[0028] When the mounting component 302 moves downward, it can drive the first mounting base 304 to move downward as well. The downward movement of the first mounting base 304 can drive the first gear 310 to move downward, thereby making the first gear 310 and the first gear plate 309 linked together, causing the first gear 310 to rotate. When the first gear 310 rotates, it can drive the first threaded rod 305 to move inside the first gear 310, thereby pushing the clamping piece 306 to move. The movement of the two clamping pieces 306 can clamp the series metal plates. The series metal plates need to cover the tabs of two adjacent cells at the same time. If the metal plates are offset, the welding point may be deviated from the center of the tab and only welded to the edge of the metal plate, resulting in insufficient conductive area. Or the metal plate may cover the cell shell and mis-weld the insulation area, resulting in an open circuit. The clamping piece 306 can firmly fix the metal plate in the preset position, ensuring that the connection area of the metal plate is completely overlapped with the two tabs, thus avoiding welding failure caused by the displacement of the metal plate from the source.
[0029] The first motor 404 can drive the second threaded rod 405 to rotate. When the second threaded rod 405 rotates, it can drive the mounting plate 403 to move up and down. The height sensor 406 can measure the height of the lithium battery cluster 209 and cause the first motor 404 to rotate according to the height. When the first motor 404 starts, it can drive the second threaded rod 405 to rotate. The rotation of the second threaded rod 405 can drive the mounting plate 403 to move up and down. The up and down movement of the mounting plate 403 can drive the first bevel gear 408, the second bevel gear 409, and the rotating disk 412 to move downward together. This causes the mounting component 302 to move downwards inside the first sliding track 301. Simultaneously, during the welding process, the second motor 410 remains running. The second motor 410 can drive the rack 411 to rotate. The rack 411 is slidably connected to the second bevel gear 409, and the rack 411 and the second bevel gear 409 mesh internally. Therefore, the rotation of the rack 411 drives the second bevel gear 409 to rotate, the rotation of the second bevel gear 409 drives the first bevel gear 408 to rotate, the rotation of the first bevel gear 408 drives the rotating disk 412 to rotate, and the rotation of the rotating disk 412 drives the rotating plate 413 to move forward. The eccentric rotation of the rotating plate 413 causes the connecting rod 414 to move up and down, which in turn causes the connecting frame 415 to move up and down, and consequently the mounting part 302 and the welding head 303 to move up and down. When the first motor 404 rotates, the initial height of the mounting part 302 inside the first sliding track 301 changes. Therefore, when the second motor 410 starts, the bottom of the welding head 303 changes. When the lithium battery cluster 209 is at a higher height, the first motor 404 drives the mounting plate 403 to move upward, thus placing the bottom of the welding head 303 at a higher position. When the lithium battery cluster 209 is at a higher height, the first motor 404 drives the mounting plate 403 to move upward, thus placing the bottom of the welding head 303 at a higher position. When the height of the battery cluster 209 is low, the lowest end of the welding head 303 is in a low position. Through the setting of the conversion mechanism 4, the distance between the welding head 303 and the lithium battery cluster 209 is always kept fixed. When the distance is dynamically adjusted with the height, the optimal energy interaction distance between the welding head 303 and the tab can always be maintained, which can ensure that the energy density of each welding is consistent, and the weld penetration and strength are uniform. This fundamentally avoids welding defects caused by height differences. The dynamic adjustment mechanism can automatically adapt to height changes through mechanical linkage without manual intervention, so that the same equipment can be compatible with clusters of all specifications from low to high, greatly improving equipment flexibility and reducing downtime for model changeover.
[0030] When the connecting frame 415 moves up and down, it drives the second gear 502 to move up and down, causing the second gear 502 to rotate. The rotation of the second gear 502 drives the third threaded rod 504 to move inside the second gear 502. In the initial stage, the electromagnet 511 is energized, causing the push plate 509 to fit against the second mounting base 501. At this time, when the connecting frame 415 moves downward, it drives the third threaded rod 504 to move, causing the movable plate 505 to compress the second spring 508, causing the second spring 508 to generate a restoring force. The control panel 512 controls the electromagnet 511 to... The welding head 303 is de-energized when welding is completed. When the welding head 303 finishes welding the next weld point, the electromagnet 511 is de-energized. Under the rebound force of the second spring 508, the push plate 509 quickly impacts and pushes the previous weld point. Welding defects such as incomplete welding, cold welding, and weld point cracking often have no abnormal appearance but insufficient internal bonding force, which is difficult to detect by visual inspection alone. When pushing the metal ear, the external force is directly applied to the connection between the welding point and the metal ear. If the welding is not firm, the metal ear will directly become loose, shift, or even fall off. Defective products can be identified on the spot to prevent them from entering subsequent processes such as assembly and packaging.
Claims
1. A cylindrical lithium battery spot welding device, comprising a platform (1), characterized in that, A spot welding mechanism (2) is installed on the top of the platform (1), the spot welding mechanism (2) comprising: The first electric slide rail (201) is fixedly installed on both sides of the platform (1). A support frame (212) is slidably installed inside the first electric slide rail (201). A second electric slide rail (202) is provided between the support frames (212). The first sliding block (203) is slidably installed inside the second electric slide rail (202), and a fixing bracket (204) is fixedly installed at the bottom of the first sliding block (203). Welding assembly (3), the welding assembly (3) is disposed on the side of the fixing frame (204), the welding assembly (3) includes a first sliding rail (301), the first sliding rail (301) is fixedly installed on the bottom of the fixing frame (204); Mounting component (302) is slidably mounted inside the first sliding track (301), and a welding head (303) is fixedly mounted on the side of the mounting component (302).
2. The cylindrical lithium battery spot welding equipment according to claim 1, characterized in that, The spot welding mechanism (2) also includes a fixing plate (205), which is fixedly installed on the top of the platform (1). There are two fixing plates (205). A clamping plate (206) is slidably installed on the top of the platform (1). There are two clamping plates (206). A first spring (207) is provided between the clamping plate (206) and the fixing plate (205). There are two first springs (207). A first limiting rod (208) is fixedly installed on the side of the clamping plate (206). The first limiting rod (208) passes through the side of the fixing plate (205) and is slidably connected to the fixing plate (205). A lithium battery cluster (209) is provided between the two clamping plates (206). A positioning plate (210) is fixedly installed on the top of the platform (1). A contact switch (211) is fixedly installed on the side of the positioning plate (210).
3. The cylindrical lithium battery spot welding equipment according to claim 2, characterized in that, The welding assembly (3) further includes a first mounting base (304), which is fixedly mounted on the bottom of the mounting component (302). There are two first mounting bases (304), and a first threaded rod (305) is rotatably mounted inside each of the two first mounting bases (304). A clamping piece (306) is fixedly mounted at the end of the first threaded rod (305), and a first limiting plate (307) is fixedly mounted at the other end of the first threaded rod (305).
4. The cylindrical lithium battery spot welding equipment according to claim 3, characterized in that, A second limiting rod (308) is fixedly installed on the side of the first limiting plate (307). The second limiting rod (308) is slidably connected to the first mounting base (304). A first toothed plate (309) is fixedly installed on the side of the fixing frame (204). A first gear (310) is rotatably installed on the side of the first mounting base (304). The first gear (310) is threadedly connected to the first threaded rod (305). The first gear (310) meshes with the first toothed plate (309).
5. The cylindrical lithium battery spot welding equipment according to claim 4, characterized in that, The fixed frame (204) is provided with a conversion mechanism (4). The conversion mechanism (4) includes a mounting groove (401). The mounting groove (401) is opened inside the fixed frame (204). A telescopic rod (402) is fixedly installed at the top of the inner cavity of the mounting groove (401). There are two telescopic rods (402). A mounting plate (403) is fixedly installed at the end of the telescopic rod (402).
6. The cylindrical lithium battery spot welding equipment according to claim 5, characterized in that, A first motor (404) is fixedly installed at the top of the inner cavity of the mounting groove (401). A second threaded rod (405) is fixedly installed at the output end of the first motor (404). The second threaded rod (405) is rotatably connected to the bottom of the inner cavity of the mounting groove (401). The second threaded rod (405) is threadedly connected to the mounting plate (403). A height sensor (406) is fixedly installed on the side of the first sliding block (203). The height sensor (406) is connected to the first motor (404) through an electrical signal.
7. The cylindrical lithium battery spot welding equipment according to claim 6, characterized in that, A side plate (407) is fixedly mounted on the side of the mounting plate (403). A first bevel gear (408) is rotatably mounted on the side of the side plate (407). A second bevel gear (409) is rotatably mounted on the top of the mounting plate (403). The first bevel gear (408) and the second bevel gear (409) mesh with each other. A second motor (410) is fixedly mounted on the top of the inner cavity of the mounting groove (401). A rack (411) is fixedly mounted on the output end of the second motor (410). The first bevel gear (408) meshes with the second bevel gear (409). A rotating disk (412) is fixedly installed on the side of the first bevel gear (408). A rotating plate (413) is rotatably installed at the eccentric part of the rotating disk (412). A connecting rod (414) is rotatably installed at the end of the rotating plate (413). A connecting frame (415) is fixedly installed on the side of the connecting rod (414). The connecting frame (415) is fixedly connected to the mounting part (302). A detection mechanism (5) is fixedly installed on the side of the connecting frame (415).
8. The cylindrical lithium battery spot welding equipment according to claim 7, characterized in that, The detection mechanism (5) includes a second mounting base (501), which is fixedly mounted on the side of the connecting frame (415). A second gear (502) is rotatably mounted on the side of the second mounting base (501). A second toothed plate (503) is fixedly mounted on the side of the fixed frame (204). The second gear (502) meshes with the second toothed plate (503). A third threaded rod (504) is installed on the internal thread of the second gear (502). A movable plate (505) is fixedly mounted on the end of the third threaded rod (504).
9. The cylindrical lithium battery spot welding equipment according to claim 8, characterized in that, A slide rod (506) is slidably installed inside the movable plate (505). A fixing groove (507) is opened on the surface of the second mounting base (501). A second spring (508) is provided inside the fixing groove (507). One end of the second spring (508) is fixedly connected to the movable plate (505). A push plate (509) is fixedly installed on the other end of the second spring (508). A guide rod (510) is fixedly installed on the side of the push plate (509). The guide rod (510) is slidably connected to the second mounting base (501). An electromagnet (511) is provided on the side of the push plate (509). A control panel (512) is fixedly installed on the side of the platform (1). The control panel (512) is connected to the electromagnet (511) and the second motor (410) through an electrical signal.
10. A method for spot welding cylindrical lithium batteries, applicable to the cylindrical lithium battery spot welding equipment described in claim 9, characterized in that, The steps are as follows: S1: In the initial stage of the device, the electromagnet (511) is energized by the control panel (512) so that the push plate (509) is in contact with the second mounting base (501) to complete the initial state setting of the device; S2: Drive the connecting frame (415) to move downward, and the connecting frame (415) drives the third threaded rod (504) to move synchronously, thereby causing the movable plate (505) to compress the second spring (508), so that the second spring (508) generates a rebound force and stores it; S3: When the welding head (303) completes the welding work of the current welding point, the control panel (512) receives the welding completion signal and controls the electromagnet (511) to perform the power-off operation; S4: After the electromagnet (511) is de-energized, it loses its attraction force on the push plate (509). At this time, the second spring (508) releases the stored rebound force and pushes the push plate (509) to quickly impact and push the previous welding point. S5: Observe the state of the metal ear after the pusher plate (509) impacts and pushes: If the metal ear becomes loose, shifts or even falls off, it indicates that the solder joint has defects such as false soldering, cold soldering or solder joint cracking. It is identified as a defective product on the spot to prevent it from entering subsequent processes such as assembly and packaging; if the metal ear is stable, the solder joint is qualified.