Battery welding positioning method and welding device

Abstract

The invention relates to the field of batteries, and discloses a battery welding positioning method and a welding device.The battery welding positioning method comprises the steps that coordinates of two fixed reference points on a battery pack and center position data of a plurality of pole columns are obtained at an addressing station; based on the coordinates of the two fixed reference points and the center position data of each pole, respectively calculating and storing geometric feature data of a geometric figure formed by the center point of each pole and the two fixed reference points; the coordinates of the two fixed reference points are obtained again at the welding station; according to the reference point coordinates obtained again and stored geometric feature data, welding position coordinates of all the pole columns under the current coordinate system are inversely calculated; based on the welding position coordinates, the welding device is guided to move to the corresponding position to execute welding; a coordinate resolving algorithm based on a fixed geometrical relationship is used for replacing a traditional mode of relying on high-precision mechanical repeated positioning, multi-link accumulative errors are eliminated fundamentally, and submillimeter-level welding positioning is achieved.

Description

Technical Field

[0001] This invention relates to the field of batteries, and in particular to a battery welding positioning method and welding apparatus. Background Technology

[0002] Currently, CTP power battery packs face significant challenges due to the variety of cell types and large cumulative positional errors after assembly. Traditional welding and positioning solutions present considerable challenges: Using a large, integrated clamping fixture with a galvanometer results in complex design, high cost, large footprint, poor flexibility, and susceptibility to welding defects due to misalignment. While point-by-point welding with an integrated single copper nozzle mechanism can improve accuracy, it suffers from slow cycle time and high equipment investment costs. Neither of these methods can guarantee high welding quality (such as weld misalignment control) while simultaneously achieving the production requirements of high efficiency, low cost, and high flexibility. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is that the traditional welding positioning scheme cannot meet the requirements of high precision, high efficiency, low cost and strong flexibility, and is difficult to adapt to the large-scale manufacturing needs of CTP power battery packs.

[0004] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a battery welding positioning method, which includes, At the addressing station, the coordinates of two fixed reference points on the battery pack and the center position data of multiple poles are obtained; Based on the coordinates of two fixed reference points and the center position data of each pole, the geometric feature data of the geometric figure formed by the center point of each pole and the two fixed reference points are calculated and stored respectively. At the welding station, the coordinates of the two fixed reference points are obtained again; Based on the re-acquired reference point coordinates and the stored geometric feature data, the welding position coordinates of each pole piece in the current coordinate system are calculated. Based on the welding position coordinates, guide the welding device to move to the corresponding position to perform welding; Specifically, the precise positions of two fixed reference points on the battery pack and each terminal post in the initial coordinate system are pre-acquired at the addressing station. Then, based on the coordinates of the two fixed reference points and the center position data of the four terminals as a group, the fixed relative positional relationship between each group of terminals and the two reference points is independently calculated and stored—this is the geometric feature data. When the battery pack is transferred to the welding station, although its overall position may have slight deviations due to transportation and positioning, by acquiring the real-time coordinates of the two fixed reference points on the same battery pack again and combining them with the pre-stored geometric feature data, the precise coordinates of each terminal post in the current welding coordinate system can be accurately reconstructed through back-calculation. Finally, the welding device is guided to move according to this series of coordinates and complete the welding. This method transforms the positioning accuracy from a hard constraint relying on high-precision mechanical repetitive positioning to a soft calculation based on fixed geometric relationships, effectively eliminating the positioning errors accumulated in multiple stages, fundamentally ensuring the absolute accuracy of the welding points, and thus significantly improving welding quality and product consistency.

[0005] In a preferred embodiment of the battery welding positioning method of the present invention: the geometric feature data is the side length data of a triangle; the triangle is composed of the center point of the pole and the two fixed reference points; Specifically, at the addressing station, for each set of poles, the three side lengths of the triangle formed by the center point of the pole and two fixed reference points are calculated and stored. Since the physical shape of the triangle on the battery pack is fixed, these three side lengths are the only expression of the absolute positional relationship of the pole relative to the two reference points. Compared with storing absolute coordinates, storing side length data does not depend on the initial coordinate system, providing a stable and reliable data foundation for subsequent coordinate inversion in different coordinate systems, and ensuring the robustness and universality of the positioning algorithm.

[0006] In a preferred embodiment of the battery welding positioning method of the present invention, the specific steps for back-calculating the welding position coordinates are as follows: Calculate the azimuth angle of the line connecting the two points based on the coordinates of the two fixed reference points obtained again. Calculate the angle between the line connecting the target pole and the line connecting the center point of the target pole, based on the side length data of the triangle corresponding to the target pole. By combining azimuth, included angle, and side length data, the coordinates of the target polar center point are determined through coordinate forward calculation. Specifically, firstly, based on the real-time coordinates of two fixed reference points acquired again at the welding station, the azimuth angle of the vector connecting these two points in the welding coordinate system is calculated. Secondly, the pre-stored triangle side length data corresponding to the target pole is retrieved, and the geometric principle of the cosine theorem is used to calculate the angle between the line connecting the reference points and the line connecting the center point of the target pole. Finally, the azimuth angle, the included angle, and the known side length data are substituted into the coordinate forward calculation formula to determine the precise coordinates of the center point of the target pole in the current welding coordinate system. This algorithm has a clear principle, stable calculation, and can achieve sub-millimeter-level high-precision positioning, effectively solving the "welding deviation" problem caused by visual distortion, mechanical errors, etc., and reliably ensuring the first-pass yield of the welding process.

[0007] In a preferred embodiment of the battery welding positioning method of the present invention: the addressing station and the welding station are separated; geometric feature data are associated, stored and retrieved across stations through the battery pack's identification code; Specifically, after data acquisition and calculation are completed at the addressing station, the generated geometric feature data does not move with the workpiece. Instead, it is bound to a unique identification code of the battery pack and stored in a central database or local cache. When a battery pack with the same identification code enters the welding station, the system automatically retrieves the corresponding geometric feature data by scanning the code. This mode decouples the functions of the workstations and optimizes the production cycle, allowing addressing and welding to be performed in parallel, greatly improving the overall production line efficiency. At the same time, centralized data management facilitates traceability, changeover, and process optimization, enhancing the flexibility and intelligence of the production system.

[0008] The present invention also provides a welding apparatus for implementing the battery welding positioning method described above, and further includes, substrate; A clamping unit, comprising a vertically retractable copper nozzle and a mounting plate for mounting the copper nozzle; the mounting plate is fixedly connected to the base plate; Specifically, the substrate is used for installation and connection with the robot. During operation, the welding device is carried and moved by the robot. When the device moves above the target welding position, multiple copper nozzles extend downwards simultaneously and act directly on the busbar of the battery pack, pressing it tightly onto the surface of the corresponding battery terminal, providing a stable and flat assembly interface for subsequent laser welding.

[0009] In a preferred embodiment of the welding device of the present invention: the copper nozzles are configured in four groups and arranged in a rectangular array; Specifically, this arrangement matches the matrix layout of common cell terminals in CTP power battery packs, allowing the device to simultaneously cover and press four adjacent terminal points with a single press. This "one-press-four" working mode improves the efficiency of the pressing action several times compared to the traditional single-point sequential pressing. At the same time, the stable and symmetrical layout of the rectangular array helps to ensure the uniformity of force on each pressing point, further ensuring the uniformity and reliability of welding quality.

[0010] In a preferred embodiment of the welding device of the present invention: a buffer spring is provided inside the copper nozzle, and the air passage inside the copper nozzle is arranged in a spiral. Specifically, the buffer spring provides elastic travel for the vertical extension and retraction of the copper nozzle, enabling it to adaptively compensate for the slight height difference between the manifold and the electrode mounting surface during the clamping process. This ensures that each clamping point can be subjected to uniform and stable positive pressure, effectively avoiding incomplete welding or welding deformation caused by uneven force. At the same time, the spiral air passage extends along the axial direction of the copper nozzle, with its outlet located near the clamping end face of the copper nozzle. During welding, the protective gas is delivered through this spiral air passage and forms a stable air curtain covering the welding area at the outlet. The spiral design increases the airflow path, making the gas flow distribution more uniform and effectively isolating air, thereby significantly improving the weld formation quality.

[0011] In a preferred embodiment of the welding device of the present invention: a dust suction pipe is provided on the outer side of the substrate, and a dust suction interface is provided on the outer side of each group of copper nozzles for connecting the dust suction pipe to the T-connector of each dust suction interface. Specifically, to address the spatter and fumes generated during welding, the negative pressure of the external dust removal equipment is transmitted to the vicinity of each copper nozzle's working point through the suction pipe, the three-way connector, and the suction interface. This allows for the efficient removal of welding fumes as they are generated, preventing their deposition on the workpiece surface and contamination of the optical lenses. This not only ensures a clean welding environment and protects the health of operators but also reduces equipment maintenance frequency and improves the long-term operational stability and reliability of the system.

[0012] The beneficial effects of this invention are as follows: by using a coordinate calculation algorithm based on fixed geometric relationships, it replaces the traditional method that relies on high-precision mechanical repetitive positioning, fundamentally eliminating the cumulative error of multiple links and achieving sub-millimeter-level welding positioning; by separating addressing and welding stations and intelligently calling data across stations, it achieves decoupling of the production process and optimization of cycle time; at the same time, by associating fixed geometric feature data with battery pack identification codes, this method can quickly adapt to different models of square or cylindrical battery packs, possessing excellent production flexibility and changeover efficiency. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0014] Figure 1 A schematic diagram of the positioning method of the present invention is shown.

[0015] Figure 2 A schematic diagram of the welding apparatus of the present invention is shown.

[0016] Figure 3 A front view of the welding apparatus of the present invention is shown. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0019] Reference Figure 1 This embodiment provides a battery welding positioning method, which includes, At the addressing station, the coordinates of two fixed reference points on the battery pack and the center position data of multiple poles are obtained; Based on the coordinates of two fixed reference points and the center position data of each pole, the geometric feature data of the geometric figure formed by the center point of each pole and the two fixed reference points are calculated and stored respectively. At the welding station, the coordinates of two fixed reference points are obtained again; Based on the re-acquired reference point coordinates and the stored geometric feature data, the welding position coordinates of each pole piece in the current coordinate system are calculated. Based on the welding position coordinates, guide the welding device to move to the corresponding position to perform welding; Specifically, the precise positions of two fixed reference points on the battery pack and each terminal post in the initial coordinate system are pre-acquired at the addressing station. Then, based on the coordinates of the two fixed reference points and the center position data of the four terminals as a group, the fixed relative positional relationship between each group of terminals and the two reference points is independently calculated and stored—this is the geometric feature data. When the battery pack is transferred to the welding station, although its overall position may have slight deviations due to transportation and positioning, by acquiring the real-time coordinates of the two fixed reference points on the same battery pack again and combining them with the pre-stored geometric feature data, the precise coordinates of each terminal post in the current welding coordinate system can be accurately reconstructed through back-calculation. Finally, the welding device is guided to move according to this series of coordinates and complete the welding. This method transforms the positioning accuracy from a hard constraint relying on high-precision mechanical repetitive positioning to a soft calculation based on fixed geometric relationships, effectively eliminating the positioning errors accumulated in multiple stages, fundamentally ensuring the absolute accuracy of the welding points, and thus significantly improving welding quality and product consistency.

[0020] The geometric feature data consists of the side lengths of a triangle; the triangle is composed of the center point of the pole and two fixed reference points. Specifically, at the addressing station, for each set of poles, the three side lengths of the triangle formed by the center point of the pole and two fixed reference points are calculated and stored. Since the physical shape of the triangle on the battery pack is fixed, these three side lengths are the only expression of the absolute positional relationship of the pole relative to the two reference points. Compared with storing absolute coordinates, storing side length data does not depend on the initial coordinate system, providing a stable and reliable data foundation for subsequent coordinate inversion in different coordinate systems, and ensuring the robustness and universality of the positioning algorithm.

[0021] The specific steps for calculating the welding position coordinates are as follows: Calculate the azimuth angle of the line connecting the two points based on the coordinates of the two fixed reference points obtained again. Calculate the angle between the line connecting the target pole and the line connecting the center point of the target pole, based on the side length data of the triangle corresponding to the target pole. By combining azimuth, included angle, and side length data, the coordinates of the target polar center point are determined through coordinate forward calculation. Specifically, firstly, based on the real-time coordinates of two fixed reference points acquired again at the welding station, the azimuth angle of the vector connecting these two points in the welding coordinate system is calculated. Secondly, the pre-stored triangle side length data corresponding to the target pole is retrieved, and the geometric principle of the cosine theorem is used to calculate the angle between the line connecting the reference points and the line connecting the center point of the target pole. Finally, the azimuth angle, the included angle, and the known side length data are substituted into the coordinate forward calculation formula to determine the precise coordinates of the center point of the target pole in the current welding coordinate system. This algorithm has a clear principle, stable calculation, and can achieve sub-millimeter-level high-precision positioning, effectively solving the "welding deviation" problem caused by visual distortion, mechanical errors, etc., and reliably ensuring the first-pass yield of the welding process.

[0022] Addressing stations and welding stations are separated; geometric feature data is associated, stored, and retrieved across stations through the battery pack's identification code; Specifically, after data acquisition and calculation are completed at the addressing station, the generated geometric feature data does not move with the workpiece. Instead, it is bound to a unique identification code of the battery pack and stored in a central database or local cache. When a battery pack with the same identification code enters the welding station, the system automatically retrieves the corresponding geometric feature data by scanning the code. This mode decouples the functions of the workstations and optimizes the production cycle, allowing addressing and welding to be performed in parallel, greatly improving the overall production line efficiency. At the same time, centralized data management facilitates traceability, changeover, and process optimization, enhancing the flexibility and intelligence of the production system.

[0023] In summary, at the addressing station, the coordinates of two fixed reference points on the battery pack and the center position data of each terminal post are first acquired. Then, based on the coordinates of the two fixed reference points and the center position data of four terminal posts per group, the three side lengths of the triangle formed by the center point of each terminal post and the two fixed reference points are calculated and stored for each group of terminal posts, serving as geometric feature data. This data is bound to the unique identification code of the battery pack, achieving a fixed and digital description of the relative positions of the terminal posts. When the battery pack enters the welding station, the system retrieves the geometric feature data of the corresponding identification code by scanning the code and again acquires the coordinates of the two fixed reference points on the same battery pack in real time. Based on these real-time coordinates and the pre-stored triangle side length data, the system calculates the azimuth angle of the line connecting the two points, solves the included angle by combining the side length data, and finally substitutes it into the coordinate forward calculation formula to accurately reconstruct the welding position coordinates of each terminal post in the current welding coordinate system. Based on this coordinate sequence, the welding device is guided to move and welding is performed.

[0024] As one embodiment provided, such as Figure 2 , Figure 3 A welding apparatus for implementing a battery welding positioning method, further comprising: substrate1; The clamping unit 2 includes a vertically telescopic copper nozzle 21 and a mounting plate 22 for mounting the copper nozzle 21; the mounting plate 22 is fixedly connected to the base plate 1. Specifically, the substrate 1 is used for installation and connection with the robot. During operation, the entire welding device is carried and moved by the robot. When the device moves above the target welding position, multiple copper nozzles 21 extend downwards simultaneously and act directly on the busbar of the battery pack, pressing it tightly onto the surface of the corresponding battery terminal, providing a stable and flat assembly interface for subsequent laser welding.

[0025] The copper nozzles 21 are set in four groups and arranged in a rectangular array; Specifically, this arrangement matches the matrix layout of common cell terminals in CTP power battery packs, allowing the device to simultaneously cover and press four adjacent terminal points with a single press. This "one-press-four" working mode improves the efficiency of the pressing action several times compared to the traditional single-point sequential pressing. At the same time, the stable and symmetrical layout of the rectangular array helps to ensure the uniformity of force on each pressing point, further ensuring the uniformity and reliability of welding quality.

[0026] The copper nozzle 21 is equipped with a buffer spring, and the air passage inside the copper nozzle 21 is arranged in a spiral. Specifically, the buffer spring provides elastic travel for the vertical extension and retraction of the copper nozzle 21, enabling it to adaptively compensate for the slight height difference between the manifold and the electrode mounting surface during the clamping process. This ensures that each clamping point can be subjected to uniform and stable positive pressure, effectively avoiding incomplete welding or welding deformation caused by uneven force. At the same time, the spiral air passage extends along the axial direction of the copper nozzle, with its outlet located near the clamping end face of the copper nozzle 21. During welding, the protective gas is delivered through this spiral air passage and forms a stable air curtain covering the welding area at the outlet. The spiral design increases the airflow path, making the gas flow distribution more uniform and more effectively isolating air, thereby significantly improving the weld formation quality.

[0027] A dust suction pipe 11 is provided on the outer side of the substrate 1, and a dust suction interface 23 is provided on the outer side of each set of copper nozzles 21 for connecting the dust suction pipe 11 to the three-way connector 3 of each dust suction interface 23. Specifically, to address the spatter and fumes generated during welding, the negative pressure of the external dust removal equipment is transmitted to the vicinity of the working point of each copper nozzle 21 through the dust suction pipe 11, the three-way connector 3, and the dust suction interface 23 during operation. This allows for the efficient removal of welding fumes as they are generated during welding, thus preventing the deposition of welding fumes on the workpiece surface and contamination of the optical lenses. This not only ensures a clean welding environment and the health of the operators but also reduces the frequency of equipment maintenance and improves the long-term operational stability and reliability of the system.

[0028] In summary, the substrate 1 is connected to the robot's end effector and is moved as a whole by the robot. When the device moves to the target welding position, the clamping unit 2 fixed on the substrate 1 actuates, causing each set of copper nozzles 21 to extend downwards and tightly press the battery busbar onto the corresponding terminal post. The copper nozzles 21 are arranged in a rectangular array, matching the layout of the battery terminal posts, achieving simultaneous clamping of four points with a single press, greatly improving clamping efficiency and cycle time. The buffer spring inside each copper nozzle 21 can adaptively compensate for the height difference of the assembly surface, ensuring uniform and stable clamping force and avoiding incomplete welding. At the same time, the spiral air passage inside the copper nozzle 21 can smoothly deliver protective gas to the welding area, forming a uniform air curtain, effectively isolating air and significantly improving weld quality. In addition, the dust extraction pipe 11 located on the outside of the substrate 1 is connected to the dust extraction interface 23 on the outside of each set of copper nozzles 21 through the T-connector 3, forming an integrated dust extraction system, which can promptly remove fumes and dust during welding, keeping the working environment clean and reducing equipment pollution and maintenance frequency.

[0029] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A method of battery weld positioning, the method comprising: Comprising, At the addressing station, the coordinates of two fixed reference points on the battery pack and the center position data of the plurality of poles are acquired; Based on the coordinates of the two fixed reference points and the center position data of each pole, the geometric feature data of the geometric figure formed by each pole center point and the two fixed reference points is calculated and stored respectively; At the welding station, the coordinates of the two fixed reference points are acquired again; According to the coordinates of the reference points acquired again and the stored geometric feature data, the welding position coordinates of each pole in the current coordinate system are calculated inversely; Based on the welding position coordinates, the welding device is guided to move to the corresponding position to perform welding.

2. The battery welding positioning method of claim 1, wherein: The geometric feature data is the side length data of a triangle formed by the pole center point and the two fixed reference points.

3. The battery welding positioning method of claim 2, wherein: The specific steps of calculating the welding position coordinates inversely are as follows: According to the coordinates of the two fixed reference points acquired again, the azimuth angle of the line connecting the two points is calculated; According to the side length data of the triangle corresponding to the target pole, the included angle between the line connecting the two points and the line connecting the target pole center point is calculated; The coordinates of the target pole center point are determined by coordinate forward calculation combined with the azimuth angle, the included angle and the side length data.

4. The battery welding positioning method according to any one of claims 1 to 3, characterized in that: The addressing station and the welding station are separated; the geometric feature data is associated, stored and cross-station called through the identity code of the battery pack.

5. A welding device characterized by: The battery welding positioning method according to any one of claims 1-4, further comprising, A base plate (1); A pressing unit (2) comprising a vertically telescopic copper nozzle (21) and a mounting plate (22) for mounting the copper nozzle (21); the mounting plate (22) is fixedly connected with the base plate (1).

6. The welding device of claim 5, wherein: The copper nozzle (21) is arranged in four groups and arranged in a rectangular array.

7. The welding device of claim 6, wherein: A buffer spring is arranged in the copper nozzle (21), and an air duct in the copper nozzle (21) is arranged in a spiral.

8. The welding apparatus of any one of claims 5-7, wherein: A dust suction connecting pipe (11) is arranged on the outside of the base plate (1), and a dust suction interface (23) is arranged on the outside of each copper nozzle (21) for connecting the dust suction connecting pipe (11) and the three-way connector (3) connecting each dust suction interface (23).

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