Welding head, welding device and welding system

Abstract

The application discloses a welding head, a welding device and a welding system, and belongs to the technical field of ultrasonic welding. The welding head is used for welding cell tabs and comprises a welding head body having a working surface surrounding a rotating axis of the welding head. The working surface comprises a welding surface and a clearance surface connected with each other. The welding surface is in a circular arc shape, and the distance from the clearance surface to the rotating axis is smaller than the radius of the welding surface except for the end part. Through the arrangement of the welding surface and the clearance surface, the continuity and operation efficiency of ultrasonic pre-welding of the cell tab are improved, the process beat of the whole battery production line is improved, the proportion of the welding mark virtual welding area on the cell tab is reduced, and the welding quality is optimized.

Description

Technical Field

[0001] This application belongs to the field of ultrasonic welding technology, and particularly relates to a welding head, welding device and welding system. Background Technology

[0002] In battery manufacturing, welding the cell tabs is one of the key steps. In related technologies, the welding device uses a circular, fully toothed welding head to feed the cell tabs to the ultrasonic welding area via a step-feed method. However, this method has the following drawbacks: First, the welding head needs to reciprocate through pressing down and lifting up after welding, which limits the production line cycle time; second, the start and end points of the weld mark have acceleration and deceleration intervals, resulting in incomplete welds and severely affecting the welding quality. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a welding head, welding device, and welding system to improve the cycle time of the entire battery production line, reduce the proportion of poor solder joints on the cell tabs, and optimize welding quality.

[0004] In a first aspect, this application provides a welding head for welding battery cell tabs, comprising:

[0005] The welding head body has a working surface surrounding the rotation axis of the welding head. The working surface includes a connected welding surface and a clearance surface. The welding surface is arc-shaped, and the distance from the rotation axis to the clearance surface, except for the end, is less than the radius of the welding surface.

[0006] According to the welding head of this application, by setting the aforementioned welding surface and avoidance surface, the welding head does not need to perform reciprocating actions of pressing down and lifting during the welding process, directly reducing the mechanical motion cycle. The welding head seamlessly transitions to the next welding point during continuous rotation without stopping or adjusting its position, thereby significantly improving the continuity and operational efficiency of ultrasonic pre-welding of the battery cell tabs, and thus greatly increasing the process cycle time of the entire battery production line. At the same time, the acceleration and deceleration of the welding head and the synchronous emission of ultrasound can be carried out before the battery cell tabs arrive, effectively avoiding contact between the welding head and the battery cell tabs during acceleration and deceleration, greatly reducing the proportion of poor solder areas on the battery cell tabs, maintaining the uniformity and consistency of the solder marks, thereby optimizing the welding quality of ultrasonic pre-welding of the battery cell tabs, and thus greatly improving the qualification rate of the final product.

[0007] According to one embodiment of this application, there are multiple welding surfaces and multiple avoidance surfaces, and the multiple welding surfaces and multiple avoidance surfaces are arranged alternately.

[0008] According to the welding head of this application, through the structural design of multiple welding surfaces and multiple avoidance surfaces arranged alternately, the welding head can complete the welding of multiple battery cell tabs in one rotation cycle, thereby improving production efficiency.

[0009] According to one embodiment of this application, the welding surface is textured.

[0010] According to one embodiment of this application, the welding head further includes:

[0011] A connecting shaft is provided, and the welding head body is connected to the connecting shaft.

[0012] According to one embodiment of this application, the avoidance surface is planar.

[0013] According to one embodiment of this application, the avoidance surface is arc-shaped.

[0014] Secondly, this application provides a welding apparatus for welding battery cell tabs, the welding apparatus comprising:

[0015] Such as any of the above-mentioned weld joints.

[0016] According to the welding apparatus of this application, by setting the welding head as described above, the welding head does not need to perform reciprocating actions of pressing down and lifting during the welding process, directly reducing the mechanical motion cycle. The welding head seamlessly transitions to the next welding point during continuous rotation without stopping or adjusting its position, thereby significantly improving the continuity and operational efficiency of ultrasonic pre-welding of the battery cell tabs, and thus greatly increasing the process cycle of the entire battery production line. At the same time, the acceleration and deceleration of the welding head and the synchronous emission of ultrasound can be carried out before the battery cell tabs arrive, effectively avoiding contact between the welding head and the battery cell tabs during acceleration and deceleration, greatly reducing the proportion of poor solder areas on the battery cell tabs, maintaining the uniformity and consistency of the solder marks, thereby optimizing the welding quality of ultrasonic pre-welding of the battery cell tabs, and thus greatly improving the qualification rate of the final product.

[0017] According to one embodiment of this application, the welding heads are arranged in pairs, and the working surfaces of the two welding heads arranged in pairs are arranged opposite to each other.

[0018] According to the welding apparatus of this application, the structural design of the working surfaces of the two welding heads arranged in pairs facing each other makes the mass distribution of the welding heads uniform and the vibration mode better, which is conducive to maintaining the stability of the welding effect. At the same time, welding both sides of the battery cell tab can reduce the welding cycle time and improve production efficiency.

[0019] According to one embodiment of this application, the welding apparatus further includes:

[0020] The transmission device has multiple transmission stations for placing the battery cells to be welded, and the distance between the solder marks of the battery cells on two adjacent transmission stations is equal to the arc length of the virtual arc between the two ends of the avoidance surface when the welding head rotates, and the center of the virtual arc is located on the rotation axis of the welding head.

[0021] According to the welding apparatus of this application, the battery cells to be welded are conveyed one by one to the welding station through the above-mentioned transmission device. By designing multiple transmission stations, a continuous production line can be formed, so that the welding process of the battery cells can be automated and continuous, which greatly improves the production efficiency. At the same time, the welding head can accurately align with the solder mark of the battery cell tab without additional adjustment or positioning steps, thereby improving the welding accuracy and efficiency.

[0022] Thirdly, this application provides a welding system for welding battery cell tabs, the welding system comprising:

[0023] Welding apparatus as described above;

[0024] A control system, in the case where the welding apparatus includes a transmission device, is used to control the welding head and the transmission device.

[0025] According to the welding system of this application, the above-mentioned welding device significantly improves the continuity and operational efficiency of ultrasonic pre-welding of battery cell tabs, thereby greatly increasing the cycle time of the entire battery production line. At the same time, it significantly reduces the proportion of poor weld areas on the battery cell tabs, thereby optimizing the welding quality of ultrasonic pre-welding of battery cell tabs and thus greatly improving the pass rate of the final product. In addition, the efficient welding device, combined with the precise control system, realizes high-precision and high-efficiency welding of battery cell tabs, achieves a high degree of automation of the welding system, and improves product quality and production efficiency.

[0026] According to one embodiment of this application, the control system is configured to adjust the rotational speed of the welding head when it is determined that the offset between the actual position of the next battery cell to be welded and the reference position is less than a target value; and to control the welding head to decelerate to a reset when it is determined that the offset between the actual position of the next battery cell to be welded and the reference position is not less than a target value, and to control the transmission device to transmit the next battery cell to be welded to the waste removal station.

[0027] According to the welding system of this application, through the logic design of the above-mentioned control system with correction function, the rotation speed of the welding head is monitored and dynamically adjusted in real time, so that the welding process is carried out when the position deviation of the battery cell is small. This can effectively reduce the risk of blank welding or poor welding caused by defective incoming materials, thereby improving the accuracy and stability of welding. The automated processing of battery cells with excessive deviation can reduce manual intervention and downtime, thereby improving the production efficiency of the entire welding system. The timely transmission of battery cells with excessive deviation to the waste removal station can prevent unqualified products from entering subsequent processes, thereby reducing scrap rate and production costs.

[0028] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0029] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0030] Figure 1 This is one of the structural schematic diagrams of the welding head provided in the embodiments of this application;

[0031] Figure 2 yes Figure 1 Enlarged view of the structure at point A in the middle;

[0032] Figure 3 This is the second schematic diagram of the structure of the welding head provided in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the texture structure provided in the embodiments of this application;

[0034] Figure 5 This is the third schematic diagram of the structure of the welding head provided in the embodiments of this application;

[0035] Figure 6 This is one of the schematic diagrams showing the state of the welding apparatus provided in this application during the welding of battery cell tabs;

[0036] Figure 7 This is the second schematic diagram of the state of the welding device provided in the embodiments of this application during the welding of the battery cell tabs;

[0037] Figure 8 This is the third schematic diagram of the state of the welding device provided in the embodiments of this application during the welding of the battery cell tabs;

[0038] Figure 9 This is a schematic diagram showing the positional status of the already welded battery cell and the next battery cell to be welded.

[0039] Figure 10This is a control logic diagram of the control system provided in the embodiments of this application.

[0040] Figure label:

[0041] Welding head 100, welding head body 110, welding surface 111, texture 112, clearance surface 113, main body surface 1131, connecting surface 1132, connecting shaft 120;

[0042] Battery cell 200, battery cell tab 210. Detailed Implementation

[0043] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0044] This application discloses a welding head 100 for welding battery cell tabs 210.

[0045] In some embodiments, such as Figure 1 As shown, the welding head 100 includes: a welding head body 110.

[0046] The welding head body 110 has a working surface surrounding the rotation axis of the welding head 100. The working surface includes a weld surface 111 and a clearance surface 113 connected to each other. The weld surface 111 is arc-shaped, and the distance from the clearance surface 113, except for the end, to the rotation axis is less than the radius of the weld surface 111.

[0047] like Figure 1 and Figure 6 As shown, the welding head body 110, as the main part of the welding head 100, is designed around a central axis to achieve rotational movement. The welding head body 110 is the part that directly contacts the battery cell tab 210 during the welding process.

[0048] The shape of the welding head body 110 may include, but is not limited to, a cylindrical shape, a disc shape, a cone shape, or an irregular polyhedron shape, etc., and no restrictions are imposed here.

[0049] For example, such as Figure 1 As shown, the shape of the welding head body 110 can be an irregular polyhedron, wherein the working surface is the side wall surface of the welding head body 110.

[0050] The working surface is the surface on the welding head body 110 used for welding operations. The working surface includes a welding surface 111 and a clearance surface 113. The welding surface 111 is the area on the working surface used for the actual welding of the battery cell tabs 210. The center of the arc-shaped welding surface 111 is located on the rotation axis. The arc-shaped design of the welding surface 111 provides continuous contact points during welding, contributing to a uniform welding effect. The clearance surface 113 is the area on the working surface other than the welding surface 111. Since the distance from the clearance surface 113 (excluding the ends) to the rotation axis is less than the radius of the welding surface 111, the ends are the connection points between the clearance surface 113 and the welding surface 111. The design of the clearance surface 113 allows for direct contact between the two welding heads 100 when there are no battery cell tabs 210 at the welding station, reducing damage and wear.

[0051] In related technologies, current welding devices use round, fully toothed welding heads for both the upper and lower dies. During the welding process, the battery cell is fed to the roll welding area via a step-feed method. The upper die welding head presses down to contact the battery cell, and then accelerates its rotation while simultaneously emitting ultrasonic waves for welding. After welding, the welding head decelerates and lifts upwards, and the battery cell is fed to the next station by a stepping mechanism. However, this solution has many drawbacks in practical applications. First, to prevent the upper and lower die welding heads from colliding, the pressing and lifting process must be repeated after each battery cell tab is welded, significantly reducing production efficiency. Furthermore, in this situation, the welding head needs to accelerate from 0 to the target speed when it first contacts the battery cell tab, and similarly, it needs to decelerate from the target speed to 0 just before detaching from the battery cell tab. Therefore, under the influence of the acceleration zone of the welding head, a cold weld zone will appear at the beginning of the battery cell tab, and under the influence of the deceleration zone, a cold weld zone will also appear at the end of the battery cell tab, seriously affecting the welding quality and thus reducing the final product qualification rate.

[0052] It is understandable that, taking an ultrasonic welding device as an example, during the operation of the welding head 100, after the welding surface 111 completes the ultrasonic welding of the electrode tab 210 of one of the battery cells 200, the battery cell 200 leaves the welding station. Before the next battery cell 200 arrives at the welding station, there is a material change time. During this material change time, the welding station is idle. The welding head 100 rotates until the clearance surface 113 faces the idle welding station. Since the distance from the clearance surface 113 (excluding the end) to the rotation axis is less than the distance from the welding surface 111 to the rotation axis, in other words, the welding surface 111 protrudes radially outward relative to the clearance surface 113. The clearance surface 113 does not participate in the welding process when the welding head 100 rotates. After ultrasonically welding a single electrode tab, the welding head 100 does not need to... When raised, it can continue to rotate at high speed as usual and emit ultrasonic waves simultaneously. During the material change time, the avoidance surface 113 of the welding head 100 of the upper and lower molds will not make direct contact or even collision with the welding surface 111 because it is retracted inward. This reduces the damage to the welding head 100 when there is no cell tab 210 at the welding station. During the material change time, the welding head 100 can take the opportunity to adjust its own speed. That is, the acceleration and deceleration of the welding head 100 are completed between two adjacent cells 200. In this way, when the welding head 100 reaches the next cell tab 210 to be welded, the speed of the welding head 100 has been adjusted to the target speed. When leaving the cell tab 210, the speed of the welding head 100 can still be maintained at the target speed, so that there are no more cold solder joints at the beginning and end of the cell tab 210, thereby greatly improving the welding quality.

[0053] The welding head 100 provided in this embodiment, through the aforementioned welding surface 111 and avoidance surface 113, eliminates the need for reciprocating pressing and lifting motions during the welding process, directly reducing the mechanical motion cycle. The welding head 100 seamlessly transitions to the next welding point during continuous rotation without pause or position adjustment, thereby significantly improving the continuity and operational efficiency of ultrasonic pre-welding of the cell tab 210, and thus greatly increasing the cycle time of the entire battery production line. Simultaneously, the acceleration and deceleration of the welding head 100 and the synchronous emission of ultrasound can be performed before the cell tab 210 arrives, effectively avoiding contact between the welding head 100 and the cell tab 210 during acceleration and deceleration. This significantly reduces the proportion of poor solder joints on the cell tab 210, maintaining the uniformity and consistency of the solder joints, thereby optimizing the welding quality of the ultrasonic pre-welding of the cell tab 210 and significantly improving the final product's pass rate.

[0054] In some embodiments, such as Figure 1 and Figure 3 As shown, there are multiple welding surfaces 111 and multiple avoidance surfaces 113, and the multiple welding surfaces 111 and multiple avoidance surfaces 113 are arranged alternately.

[0055] like Figure 1 and Figure 3 As shown, the welding head 100 has an overall irregular symmetrical design. The number of welding surfaces 111 and the number of avoidance surfaces 113 are the same. Here, "multiple" means two or more. In some embodiments, the number N of welding surfaces 111 / avoidance surfaces 113 satisfies: 2≤N≤9.

[0056] For example, in some embodiments, such as Figure 1 and Figure 3 As shown, there are three welding surfaces 111 and three clearance surfaces 113. The three welding surfaces 111 and the three clearance surfaces 113 are arranged alternately. In this way, the welding head 100 can complete the welding of the three battery cell tabs 210 in one rotation.

[0057] For example, in other embodiments, such as Figure 5 As shown, there are two welding surfaces 111 and two clearance surfaces 113. The two welding surfaces 111 and the two clearance surfaces 113 are arranged alternately. In this way, the welding head 100 can complete the welding work of the two battery cell tabs 210 by rotating one revolution.

[0058] For example, in some other embodiments, there are four welding surfaces 111 and four avoidance surfaces 113, and the four welding surfaces 111 and four avoidance surfaces 113 are arranged alternately, so that the welding head 100 can complete the welding of four battery cell tabs 210 in one rotation.

[0059] The welding head 100 provided in this application embodiment, through the structural design of the above-mentioned multiple welding surfaces 111 and multiple avoidance surfaces 113 being arranged in an alternating manner, enables the welding head 100 to complete the welding work of multiple battery cell tabs 210 in one rotation cycle, thereby improving production efficiency.

[0060] In some embodiments, such as Figures 1-2 As shown, the welding surface 111 has texture 112.

[0061] The texture 112 can be designed as a convex tooth structure. Specifically, the convex tooth structure can include straight tooth type and helical tooth type.

[0062] Texture 112 may include, but is not limited to, trapezoidal block texture, straight stripe texture, mesh stripe texture, spiral stripe texture, wavy stripe texture, dot texture or other irregular texture, etc., without limitation.

[0063] For example, such as Figure 2 and Figure 4 As shown, the texture 112 is designed as a trapezoidal block texture 112, which can be distributed in an array on the welding surface 111.

[0064] Among them, such as Figure 4As shown, taking the trapezoidal block pattern 112 as an example, the tooth height of the trapezoidal block pattern 112 is h, and the tooth pitch of the trapezoidal block pattern 112 is s. The specific values ​​of h and s can be adjusted according to the actual needs of the battery cell 200 and the production line.

[0065] The welding head 100 provided in this application embodiment, through the design of the above-mentioned texture 112, can increase the actual contact area between the welding surface 111 and the battery cell tab 210, which helps to transfer heat and pressure more evenly, promotes the melting and flow of the battery cell tab 210 material on the welding surface 111, improves the fusion effect and welding strength, and thus further improves the welding quality.

[0066] In some embodiments, such as Figure 1 and Figures 5-6 As shown, the welding head 100 also includes a connecting shaft 120.

[0067] The welding head body 110 is connected to the connecting shaft 120.

[0068] like Figure 1 and Figures 5-6 As shown, the connecting shaft 120 is connected between the drive mechanism of the welding device and the welding head body 110 as a transmission mechanism. In other words, the drive mechanism of the welding device is poweredly connected to the connecting shaft 120. The drive mechanism drives the connecting shaft 120 to rotate around the axial direction, thereby causing the welding head body 110 to rotate around the rotation axis. The axial direction of the connecting shaft 120 is collinear with the rotation axis of the welding head body 110.

[0069] In some embodiments, the welding head body 110 can be detachably connected to the connecting shaft 120. Specifically, the welding head body 110 can be designed with a standard connection interface, such as a threaded hole or a pin hole. One end of the connecting shaft 120 is designed with a shape that matches the connection interface of the welding head body 110, such as a thread or a pin. The connecting shaft 120 is tightly connected to the welding head body 110 by rotation or insertion. The other end of the connecting shaft 120 is connected to the drive mechanism of the welding device to transmit rotational force and ultrasonic energy.

[0070] In other embodiments, the welding head body 110 and the connecting shaft 120 can be directly integrated by processes such as casting, forging or precision machining. Specifically, a portion of the connecting shaft 120 is directly embedded in the design of the welding head body 110, becoming an inseparable part of it. The integrated connecting shaft 120 is connected to the drive mechanism of the welding device by bolts, flanges or other fastening methods.

[0071] In some other embodiments, the connecting shaft 120 can be made of an elastic material, such as spring steel or rubber. One end of the connecting shaft 120 is fixedly connected to the welding head body 110, and the other end is connected to the drive mechanism of the welding device through an elastic element (such as a spring or rubber pad). The elastic connecting shaft 120 can absorb and mitigate the impact and vibration generated during the welding process.

[0072] In other embodiments, the connecting shaft 120 can also be designed as an adjustable-angle structure, such as through a universal joint, ball joint, etc., to achieve multi-degree-of-freedom adjustment. The adjustment mechanism allows the angle and position between the welding head body 110 and the battery cell tab 210 to be adjusted within a certain range. The adjustment mechanism can be controlled manually or automatically.

[0073] The welding head 100 provided in this embodiment of the application realizes the power transmission and ultrasonic energy transmission between the welding head 100 and the drive mechanism of the welding device through the above-mentioned connecting shaft 120. The connecting shaft 120 can provide necessary support for the welding head 100, maintain the stability of the welding head 100 during the welding process, and the assembly method between the connecting shaft 120, the welding head body 110 and the drive mechanism of the welding device can be designed according to actual needs, so that the welding head 100 can adapt to the welding needs of battery cell tabs 210 of different shapes, sizes and positions, thereby improving the flexibility and adaptability of welding.

[0074] In some embodiments, such as Figure 1 , Figure 3 and Figures 6-8 As shown, the avoidance surface 113 is planar.

[0075] In this embodiment, such as Figure 1 , Figure 3 and Figures 6-8 As shown, the clearance surface 113 is designed as a flat and continuous surface. The clearance surface 113 can be regarded as the cut surface obtained after cutting the complete disc-shaped welding head body. In other words, the line connecting the two ends of the clearance surface 113 is a chord of the virtual circle where the arc-shaped welding surface 111 is located.

[0076] In other embodiments, the clearance surface 113 includes a plurality of sequentially connected planes. For example, if a groove is carved out of the complete disc-shaped welding head body, the clearance surface 113 can be regarded as the bottom wall and side wall of the groove.

[0077] The welding head 100 provided in this embodiment features a planar design for the clearance surface 113. When there are no battery cell tabs 210 at the welding station during material changeover, the planar clearance surface 113 reduces contact with other parts of the welding head 100 or the machine frame, avoiding unnecessary wear. Furthermore, the planar clearance surface 113 is relatively simple in design, easy to process and manufacture, and can adapt to the welding requirements of battery cell tabs 210 of different specifications and shapes. By adjusting the width and position of the clearance surface 113, various welding conditions can be flexibly addressed.

[0078] In some embodiments, such as Figure 5 As shown, the clearance surface 113 is an arc shape.

[0079] In this embodiment, such as Figure 5 As shown, the clearance surface 113 may include a main surface 1131 and a connecting surface 1132. The connecting surface 1132 connects the main surface 1131 and the welding surface 111. Both the main surface 1131 and the connecting surface 1132 are arc surfaces. The curvature center of the main surface 1131 and the curvature center of the connecting surface 1132 are located on both sides of the entire clearance surface 113. That is, the bending direction of the main surface 1131 and the bending direction of the connecting surface 1132 can be opposite. The center of the main surface 1131 can coincide with the center of the welding surface 111, and the radius of the circle corresponding to the main surface 1131 can be smaller than the radius of the circle corresponding to the welding surface 111.

[0080] In other embodiments, the avoidance surface 113 may also consist of only a continuous arc surface.

[0081] The central angle corresponding to the clearance surface 113 can be greater than, equal to or less than the central angle corresponding to the welding surface 111. The specific value of the central angle corresponding to the clearance surface 113 can be designed according to the distance between two adjacent battery cell tabs 210.

[0082] For example, in some embodiments, such as Figure 5 As shown, the central angle corresponding to the avoidance surface 113 is greater than the central angle corresponding to the welding surface 111.

[0083] The welding head 100 provided in this embodiment features an arc-shaped avoidance surface 113, which corresponds to the arc-shaped welding surface 111, creating a continuous and smooth transition. This design also provides greater convenience during maintenance and cleaning. Furthermore, during the rotation of the welding head 100, it smoothly bypasses the already welded or yet-to-be-welded battery cell tabs 210, reducing direct collisions and interference with the battery cell tabs 210. This helps reduce damage to the welding head 100 and deformation of the battery cell tabs 210, improving the stability and reliability of the welding process.

[0084] It should be noted that, in addition to the planar and arc-shaped types mentioned above, the avoidance surface 113 can also be other types of surfaces, such as sawtooth, wavy, or any irregular shape, without any restrictions here.

[0085] This application also discloses a welding apparatus for welding the battery cell tabs 210.

[0086] In some embodiments, such as Figures 6-8 As shown, the welding apparatus includes a welding head 100 as described above.

[0087] For example, such as Figures 6-8 As shown, the welding device can be an ultrasonic flying roll welding device. The driving mechanism of the welding device can include a motor and an ultrasonic transducer to realize the rotation of the welding head 100 and ultrasonic output.

[0088] It should be noted that the welding device is not limited to the ultrasonic flying roll welding device mentioned above, but may also include ultrasonic horizontal welding machine, ultrasonic wedge welding machine, laser welding machine, laser welding machine, casting welding machine or tongue-type battery cell tab 210 welding device, etc., without limitation here.

[0089] The welding apparatus provided in this application embodiment, through the aforementioned welding head 100, eliminates the need for reciprocating pressing and lifting motions during the welding process, directly reducing the mechanical motion cycle. The welding head 100 seamlessly transitions to the next welding point during continuous rotation without pause or position adjustment, thereby significantly improving the continuity and operational efficiency of ultrasonic pre-welding of the cell tab 210. This, in turn, greatly increases the cycle time of the entire battery production line. Simultaneously, the acceleration and deceleration of the welding head 100 and the synchronous emission of ultrasound can be performed before the cell tab 210 arrives, effectively avoiding contact between the welding head 100 and the cell tab 210 during acceleration and deceleration. This significantly reduces the proportion of poor solder joints on the cell tab 210, maintains the uniformity and consistency of the solder joints, thereby optimizing the welding quality of ultrasonic pre-welding of the cell tab 210 and significantly improving the final product qualification rate.

[0090] In some embodiments, such as Figures 6-8 As shown, the welding heads 100 are arranged in pairs, and the working surfaces of the two welding heads 100 arranged in pairs are positioned opposite each other.

[0091] In this embodiment, such as Figures 6-8As shown, each pair of welding heads 100 may include two welding heads 100 arranged in a pressing manner. During welding, the battery cell tab 210 can be clamped between the welding surfaces 111 of the two welding heads 100 arranged in a pair. The two welding heads 100 arranged in a pair can weld both sides of the battery cell tab 210 at the same time to achieve docking. The multiple welding surfaces 111 of the two welding heads 100 can correspond one-to-one, and the multiple clearance surfaces 113 of the two welding heads 100 can correspond one-to-one.

[0092] The welding apparatus provided in this application embodiment, through the structural design of the working surfaces of the two welding heads 100 arranged in pairs facing each other, makes the mass distribution of the welding heads 100 uniform and the vibration mode better, which is conducive to maintaining the stability of the welding effect. At the same time, welding both sides of the battery cell tab 210 can reduce the welding cycle time and improve production efficiency.

[0093] In some embodiments, the welding apparatus further includes a transfer device.

[0094] like Figure 3 and Figure 9 As shown, the transmission device has multiple transmission stations for placing the battery cells 200 to be welded, and the distance W between the solder marks of the battery cells 200 on two adjacent transmission stations is equal to the arc length L2 of the virtual arc between the two ends of the clearance surface 113 when the welding head 100 rotates. The center of the virtual arc is located on the rotation axis of the welding head 100.

[0095] The transmission route of the transmission device can be a straight line or a curved line. Specifically, the transmission device can include, but is not limited to, conveyor belts, chain conveyor systems, robotic arms, slide rail systems, turntable conveyors, roller conveyor systems, lifting platforms, AGVs (Automated Guided Vehicles) or RGVs (Rail Guided Vehicles), etc. There are no restrictions here.

[0096] For example, in some embodiments, the transmission device includes a conveyor belt.

[0097] In actual implementation, with Figure 3 , Figure 7 and Figure 9 For example, if the transmission route of the transmission device is a straight line, then the transmission direction of the transmission device is... Figure 6The machining direction of the middle cell 200 and the rotation direction of the welding head 100 are designed to match the machining direction of the cell 200. The rotation direction of the welding head 100 of the upper mold is opposite to that of the welding head 100 of the lower mold. The radius R2 of the virtual arc between the two ends of the clearance surface 113 is equal to the radius R1 of the welding surface 111. During the operation of the welding device, the welding head 100 is driven to rotate at a high speed of standard rotation speed V0. At the same time, the ultrasonic generator is activated, and ultrasonic energy is transmitted to the contact surface of the battery electrode 210 through the welding head 100. Specifically, the first end of the welding surface 111 first contacts the welding start point of the battery electrode 210. After the welding head 100 rotates to the central angle corresponding to the arc with the weld length H as the arc length and the radius R1 of the welding surface 111 as the radius, the battery electrode 210 completes ultrasonic welding. At this time, the end of the welding surface 111 contacts the welding end point of the battery electrode 210. The welding head 100 continues to rotate. After the welding head 100 rotates to the central angle corresponding to the arc with the distance W between the welds of the battery 200 as the arc length and the radius R2 of the avoidance surface 113 as the radius, the first end of the next welding surface 111 contacts the welding start point of the next battery electrode 210. The subsequent stroke of the welding head 100 repeats the above actions, which will not be described in detail here.

[0098] Welding rhythm The radius R1 of welding surface 111 is equal to the radius of the virtual arc.

[0099] Among them, such as Figure 3 and Figure 9 As shown, the welding cycle time T is the time required to complete the welding of one battery cell tab 210, V0 is the standard rotation speed of the welding head 100, the arc length L1 of the welding surface 111 is equal to the weld length H, the arc length L2 of the virtual arc between the two ends of the avoidance surface 113 is equal to the distance W between the welds, and N is the number of welding surfaces 111, which is also the number of avoidance surfaces 113, satisfying: 2≤N≤9.

[0100] The length H of the solder stamp must satisfy: 20mm≤H≤200mm, and the distance W between solder stamps must satisfy: 20mm≤W≤200mm.

[0101] Specifically, the solder mark length H can be 20mm, 65.78mm, 100mm, 125.4mm, 188.786mm, 200mm or other values ​​between 20mm and 200mm, without any restrictions.

[0102] The distance W between solder marks can be 20mm, 86.32mm, 100mm, 138.5mm, 192.183mm, 200mm or other values ​​between 20mm and 200mm, and there is no restriction here.

[0103] The radius R1 of the welding surface 111 satisfies: 15mm≤R1≤100mm.

[0104] Specifically, the radius R1 of the welding surface 111 can be 15mm, 31.63mm, 60mm, 83.1mm, 92.854mm, 100mm or other values ​​between 15mm and 100mm, without any restrictions.

[0105] The welding apparatus provided in this application embodiment, through the setting of the above-mentioned transmission device, transmits the battery cells 200 to be welded one by one to the welding station. By designing multiple transmission stations, a continuous production line can be formed, so that the welding process of the battery cells 200 can be automated and continuous, which greatly improves production efficiency. At the same time, it enables the welding head 100 to accurately align with the solder mark of the battery cell tab 210 without additional adjustment or positioning steps, thereby improving the welding accuracy and efficiency.

[0106] This application also discloses a welding system for welding the battery cell tabs 210.

[0107] In some embodiments, the welding system includes a control system and welding apparatus as described above.

[0108] In the case where the welding apparatus includes a conveying device, the control system is used to control the welding head 100 and the conveying device.

[0109] In actual implementation, such as Figure 10 As shown, the welding system may also include a cell 200 inspection system. The cell 200 inspection system may include, but is not limited to, an industrial CCD (Charge-Coupled Device) camera. The industrial CCD camera is used to perform high-resolution imaging of the appearance of the cell 200, and to detect whether there are defects on the surface of the cell 200, such as dents, scratches, contamination or other irregularities. At the same time, it detects the position and alignment of the cell tabs 210 to ensure correct positioning in subsequent welding or other processing. The cell 200 inspection system feeds the inspection results back to the control system. The control system can issue corresponding control commands based on the inspection results to determine whether to perform welding operations on the cell tabs 210.

[0110] The welding system provided in this application significantly improves the continuity and operational efficiency of ultrasonic pre-welding of the cell tab 210 through the setting of the above-mentioned welding device, thereby greatly increasing the cycle time of the entire battery production line. At the same time, it significantly reduces the proportion of poor solder areas on the cell tab 210, thereby optimizing the welding quality of ultrasonic pre-welding of the cell tab 210 and thus greatly improving the pass rate of the final product. In addition, the efficient welding device, combined with the precise control system, realizes high-precision and high-efficiency welding of the cell tab 210, realizes a high degree of automation of the welding system, and improves product quality and production efficiency.

[0111] In some embodiments, such as Figures 9-10 As shown, the control system is configured to adjust the rotational speed V0 of the welding head 100 when the offset ΔL between the actual position of the next battery cell 200 to be welded and the reference position is less than the target value; and to control the welding head 100 to decelerate to reset when the offset ΔL between the actual position of the next battery cell 200 to be welded and the reference position is not less than the target value, and to control the transmission device to transmit the next battery cell 200 to be welded to the waste removal station.

[0112] In actual implementation, such as Figures 9-10 As shown, after the battery cell 200 to be welded arrives at the loading position via the conveying device, the battery cell 200 detection system takes a picture of the battery cell 200 to be welded and determines whether the offset ΔL between the actual position of the battery cell 200 to be welded and the reference position is less than the target value based on the acquired image information. If the offset ΔL between the actual position of the battery cell 200 to be welded and the reference position is less than the target value, that is, the actual position of the battery cell 200 to be welded is within the correctable limit, the battery cell 200 detection system feeds back an OK signal (i.e., a pass signal) to the control system. The control system can calculate the speed adjustment value V1 according to the calculation formula. The welding head 100 is adjusted from the standard speed V0 to the speed V1 by acceleration a, and then continues to be adjusted back to the standard speed V0 by acceleration a. In this way, the welding head 100 makes up for the defect of offset ΔL, and finally the welding head 100 and the battery cell 200 to be welded can arrive at the welding station together. If the offset ΔL between the actual position of the cell to be welded 200 and the reference position is greater than or equal to the target value, that is, if the actual position of the cell to be welded 200 exceeds the correctable limit, the cell 200 detection system feeds back an NG signal (i.e., a non-pass signal) to the control system. The control system controls the welding head 100 to decelerate to a stop, and the cell to be welded 200 enters the waste removal station. When restarting, the position of the next cell to be welded 200 needs to be adjusted to the detection position. The end of the welding surface 111 of the welding head 100 returns to the welding endpoint of the previously welded cell tab 210, and then starts. The welding head 100 and the next cell to be welded 200 are both accelerated by acceleration a, and synchronously accelerated to the standard speed V0 at the welding station to achieve the matching of welding action and position.

[0113] Specifically, when the actual position of the cell to be welded 200 is closer to the previous cell 200 than the reference position, the speed adjustment value V1 is less than V0; when the actual position of the cell to be welded 200 is farther from the previous cell 200 than the reference position, the speed adjustment value V1 is greater than V0.

[0114] It should be noted that the 200 cells to be welded at the waste discharge station need to be re-injected regularly, that is, the above-mentioned material loading and inspection steps need to be repeated, which will not be repeated here.

[0115] The welding system provided in this application embodiment, through the logic design of the above-mentioned control system with correction function, monitors and dynamically adjusts the rotation speed of the welding head 100 in real time, so that the welding process is carried out when the position deviation of the battery cell 200 is small. This can effectively reduce the risk of blank welding or poor welding caused by defective incoming materials, thereby improving the accuracy and stability of welding. The automated processing of battery cells 200 with excessive offset can reduce manual intervention and downtime, thereby improving the production efficiency of the entire welding system. The timely transmission of battery cells 200 with excessive offset to the waste removal station for processing can prevent unqualified products from entering subsequent processes, thereby reducing scrap rate and production costs.

[0116] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0117] In the description of this application, 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", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0118] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0119] In the description of this application, "multiple" means two or more.

[0120] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0121] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0122] Other configurations of the embodiments of this application, such as ... and ..., and operations, are known to those skilled in the art and will not be described in detail here.

[0123] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A welding system for welding battery cell tabs, characterized in that, include: Welding equipment; The welding apparatus includes a welding head and a transfer device; The welding head includes: The welding head body has a working surface surrounding the rotation axis of the welding head. The working surface includes a connected welding surface and a clearance surface. The welding surface is arc-shaped, and the distance from the rotation axis to the clearance surface, except for the end, is less than the radius of the welding surface. The transmission device has multiple transmission stations for placing the battery cells to be welded, and the distance between the solder marks of the battery cells on two adjacent transmission stations is equal to the arc length of the virtual arc between the two ends of the clearance surface when the welding head rotates. The center of the virtual arc is located on the rotation axis of the welding head. A control system, in the case where the welding apparatus includes a conveying device, is used to control the welding head and the conveying device; The control system is configured to, when it is determined that the offset between the actual position of the next battery cell to be welded and the reference position is less than the target value, adjust the rotation speed of the welding head. The welding head is adjusted from the standard speed V0 to the speed V1 by acceleration, and then adjusted back to the standard speed V0 by acceleration to compensate for the offset defect, so that the welding head and the battery cell to be welded arrive at the welding station together; when it is determined that the offset between the actual position of the next battery cell to be welded and the reference position is not less than the target value, control the welding head to decelerate to the reset position, and control the transmission device to transmit the next battery cell to be welded to the waste removal station. There are multiple welding surfaces and multiple avoidance surfaces, and the multiple welding surfaces and multiple avoidance surfaces are arranged alternately; The welding surface protrudes radially outward relative to the clearance surface, so that the clearance surface does not participate in the welding process when the welding head rotates; The welding heads are arranged in pairs, and the working surfaces of the two welding heads in the pair are arranged opposite each other.

2. The welding system according to claim 1, characterized in that, The welding surface has textured patterns.

3. The welding system according to claim 1, characterized in that, The welding head also includes: A connecting shaft is provided, and the welding head body is connected to the connecting shaft.

4. The welding system according to any one of claims 1-3, characterized in that, The avoidance surface is planar.

5. The welding system according to any one of claims 1-3, characterized in that, The avoidance surface is arc-shaped.

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