Welding head, welding device and welding system

Abstract

The invention 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 a battery cell tab and comprises a welding head body and a working face surrounding the rotating axis of the welding head, the working face comprises a welding face and a receding face which are connected, the welding face is in a circular arc shape, and the distance from other areas, except the end, of the receding face to the rotating axis is smaller than the radius of the welding face. Through the arrangement of the welding surface and the avoiding surface, the continuity and the operation efficiency of ultrasonic pre-welding of the battery cell tab are improved, the procedure beat of the whole battery production line is improved, the proportion of a welding print pseudo soldering area on the battery cell tab is reduced, and the welding quality is optimized.

Description

Technical Field

[0001] The present application belongs to the technical field of ultrasonic welding, and in particular relates to a welding head, a welding device and a welding system. Background Art

[0002] In the battery manufacturing process, welding of the cell tabs is one of the key steps. In the related art, the welding device uses a circular full-tooth welding head, and the cell tabs are sent to the rolling welding area for ultrasonic welding through a step-by-step feeding method. However, this method has the following shortcomings: First, the welding head needs to reciprocate to press down and lift up after welding, which limits the production line cycle; second, there are acceleration and deceleration intervals at the starting and end points of the weld mark, resulting in a virtual weld area in the weld mark, which seriously affects the welding quality. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a welding head, a welding device and a welding system to improve the process rhythm of the entire battery production line, reduce the proportion of weld marks and virtual weld areas on the battery cell tabs, and optimize the welding quality.

[0004] In a first aspect, the present application provides a welding head for welding a battery cell tab, 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 an avoidance surface, the welding surface is arc-shaped, and the distance from the avoidance surface to the rotation axis except the end is less than the radius of the welding surface.

[0006] According to the welding head of the present application, through the setting of the above-mentioned welding surface and avoidance surface, the welding head does not need to perform reciprocating movements of pressing down and lifting during the welding process, which directly reduces the mechanical movement cycle, and the welding head seamlessly transitions to the next welding point during continuous rotation without pausing or adjusting the position, thereby significantly improving the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tabs, thereby greatly improving the process rhythm of the entire battery production line, and at the same time, the acceleration and deceleration of the welding head and the synchronous emission of ultrasound can be performed before the arrival of the battery cell tabs, effectively avoiding the contact of the welding head with the battery cell tabs during the acceleration and deceleration process, greatly reducing the proportion of the weld mark virtual weld area on the battery cell tabs, maintaining the uniformity and consistency of the weld mark, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tabs, thereby greatly improving the qualified rate of the final product.

[0007] According to an embodiment of the present application, there are multiple welding surfaces and multiple avoidance surfaces, and the multiple welding surfaces and the multiple avoidance surfaces are staggered.

[0008] According to the welding head of the present application, through the structural design of the staggered arrangement of the above-mentioned multiple welding surfaces and multiple avoidance surfaces, the welding head can complete the welding work of multiple battery cell tabs within one rotation cycle, thereby improving production efficiency.

[0009] According to one embodiment of the present application, the welding surface is provided with texture.

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

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

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

[0013] According to an embodiment of the present application, the avoidance surface is in an arc shape.

[0014] In a second aspect, the present application provides a welding device for welding a battery cell tab, the welding device comprising:

[0015] A welding head as described in any one of the above.

[0016] According to the welding device of the present application, through the setting of the above-mentioned welding head, the welding head does not need to perform reciprocating movements of pressing down and lifting during the welding process, which directly reduces the mechanical movement cycle. The welding head seamlessly transitions to the next welding point during continuous rotation without pausing or adjusting the position, thereby significantly improving the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tabs, thereby greatly improving the process rhythm of the entire battery production line, and at the same time, the acceleration and deceleration of the welding head and the synchronous emission of ultrasound can be performed before the arrival of the battery cell tabs, effectively avoiding the contact between the welding head and the battery cell tabs during the acceleration and deceleration process, greatly reducing the proportion of the weld mark virtual weld area on the battery cell tabs, maintaining the uniformity and consistency of the weld mark, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tabs, thereby greatly improving the qualified rate of the final product.

[0017] According to one embodiment of the present 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 device of the present application, through the structural design in which the working surfaces of the two welding heads arranged in pairs are arranged relative to each other, the mass distribution of the welding heads is uniform and the vibration form is 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 the present application, the welding device further includes:

[0020] The transmission device has multiple transmission stations for placing battery cells to be welded, and the distance between the weld 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 device of the present application, the battery cells to be welded are transmitted to the welding station one by one through the setting of 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 be accurately docked with the welding mark of the battery cell tab without the need for additional adjustment or positioning steps, thereby improving the welding accuracy and efficiency.

[0022] In a third aspect, the present application provides a welding system for welding a battery cell tab, the welding system comprising:

[0023] A welding device as described in any one of the above;

[0024] A control system, when the welding device includes a transmission device, the control system is used to control the welding head and the transmission device.

[0025] According to the welding system of the present application, through the setting of the above-mentioned welding device, the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tabs are significantly improved, thereby greatly improving the process rhythm of the entire battery production line, and at the same time greatly reducing the proportion of the weld mark and virtual weld area on the battery cell tabs, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tabs, thereby greatly improving the qualified rate of the final product. In addition, the efficient welding device cooperates with the precise control system to achieve high-precision and high-efficiency welding of the battery cell tabs, realize the high degree of automation of the welding system, and improve product quality and production efficiency.

[0026] According to one embodiment of the present application, 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; 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 reset, and control the transmission device to transmit the next battery cell to be welded to the waste discharge station.

[0027] According to the welding system of the present application, through the logical design of the correction function configured in the above-mentioned control system, 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 battery cell position deviation is small, which can effectively reduce the risk of empty welding or poor welding caused by poor incoming materials, thereby improving the accuracy and stability of welding, and automatically processing battery cells with excessive offset can reduce manual intervention and downtime, thereby improving the production efficiency of the entire welding system, and timely transmitting battery cells with excessive offset to the waste discharge station for processing can prevent unqualified products from entering subsequent processes, thereby reducing scrap rate and production costs.

[0028] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments 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 embodiment of the present application;

[0031] Figure 2 yes Figure 1 A magnified view of the structure at center A;

[0032] Figure 3 This is the second structural schematic diagram of the welding head provided in the embodiment of the present application;

[0033] Figure 4 It is a schematic diagram of the structure of the texture provided in the embodiment of the present application;

[0034] Figure 5 This is the third structural schematic diagram of the welding head provided in the embodiment of the present application;

[0035] Figure 6 This is one of the schematic diagrams of the state of the welding device provided in the embodiment of the present application during the welding process of the battery cell tab;

[0036] Figure 7 This is the second schematic diagram of the state of the welding device provided in the embodiment of the present application during the welding process of the battery cell tab;

[0037] Figure 8 This is the third state schematic diagram of the welding device provided in the embodiment of the present application during the welding process of the battery cell tab;

[0038] Fig. 9 It is a schematic diagram of the position status of the welded battery cell and the next battery cell to be welded;

[0039] Fig.10It is a control logic diagram of the control system provided in the embodiment of the present application.

[0040] Reference numerals:

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

[0042] The battery cell 200 and the battery cell tab 210 . DETAILED DESCRIPTION

[0043] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0044] The present application discloses a welding head 100 for welding a battery cell tab 210 .

[0045] In some embodiments, 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, and the working surface includes a connected welding surface 111 and an avoidance surface 113. The welding surface 111 is arc-shaped, and the distance from the avoidance surface 113 to the rotation axis except the end is less than the radius of the welding surface 111.

[0047] like Figure 1 and Figure 6 As shown, the welding head body 110 is the main part of the welding head 100 and is designed around a central axis to achieve rotational motion. 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, etc., which is not limited here.

[0049] For example, 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, and the working surface includes a welding surface 111 and an avoidance surface 113, wherein the welding surface 111 is the area on the working surface used for actual welding of the battery cell tab 210, and the center of the arc-shaped welding surface 111 is located on the rotation axis. By designing the welding surface 111 to be an arc, continuous contact points can be provided during the welding process, which helps to achieve a uniform welding effect. The avoidance surface 113 is the area on the working surface other than the welding surface 111. Based on the fact that the distance from the other areas of the avoidance surface 113 except the end to the rotation axis is less than the radius of the welding surface 111, the end is the connection position of the avoidance surface 113 and the welding surface 111. The design of the avoidance surface 113 allows the two welding heads 100 to avoid direct contact with each other when there is no battery cell tab 210 at the welding station, thereby reducing damage and wear.

[0051] In the related art, the upper and lower molds of the current welding device both use a circular full-tooth welding head. During the welding process, the battery cell is sent to the rolling welding area by a step-by-step feeding method. The upper mold welding head presses down to contact the battery cell, and the welding head begins to accelerate and rotate and simultaneously emits ultrasound for welding. After the welding is completed, the welding head slows down and lifts up, and the battery cell is sent to the next station by the stepping mechanism. However, the above scheme has many disadvantages in actual application. First, in order to prevent the upper and lower mold welding heads from colliding with each other, each time a battery cell tab is welded, it is necessary to repeat the steps of pressing down first and then lifting up, which significantly reduces the production efficiency. In this case, the welding head needs to accelerate the speed from 0 to the target speed when it just contacts the battery cell tab. Similarly, the welding head needs to decelerate the speed from the target speed to 0 when it is about to leave the battery cell tab. Therefore, under the influence of the acceleration zone of the welding head, a cold welding area will appear at the head end of the battery cell tab, and under the influence of the deceleration zone of the welding head, a cold welding area will also appear at the end of the battery cell tab, which seriously affects the welding quality, thereby reducing the qualified rate of the final product.

[0052] It can be understood that, taking the welding device as an ultrasonic welding device as an example, during the working process of the welding head 100, after the welding surface 111 completes the ultrasonic welding of the battery cell pole ear 210 of one of the battery cells 200, the battery cell 200 leaves the welding station, and there is a period of material change time before the next battery cell 200 arrives at the welding station. During the material change time, the welding station is in an idle state, and the welding head 100 rotates until the avoidance surface 113 is facing the welding station in the idle state. Based on the fact that the distance from the avoidance surface 113 to the rotation axis except the end is less than the distance from the welding surface 111 to the rotation axis, in other words, the welding surface 111 protrudes radially outward compared to the avoidance surface 113, and the avoidance surface 113 will not participate in the welding process when the welding head 100 rotates. After the welding head 100 completes ultrasonic welding of a single-core pole ear, there is no need Lifting up, it can continue to rotate at a high speed as normal and emit ultrasonic waves simultaneously. During the material changing time, the avoidance surface 113 of the welding head 100 of the upper and lower molds is inwardly contracted compared to the welding surface 111, so that no direct contact or even collision will occur, so as to reduce the damage of the welding head 100 when there is no battery cell tab 210 at the welding station. During the material changing time, the welding head 100 can take the opportunity to adjust its own rotation speed, that is, the acceleration and deceleration of the welding head 100 are completed between two adjacent battery cells 200. In this way, when the welding head 100 arrives at the next battery cell tab 210 to be welded, the speed of the welding head 100 has been adjusted to the target speed. When leaving the battery cell tab 210, the speed of the welding head 100 can still be maintained at the target speed, so that there is no cold solder joint area at the beginning and end of the battery cell tab 210, thereby greatly improving the welding quality.

[0053] The welding head 100 provided in the embodiment of the present application, through the arrangement of the above-mentioned welding surface 111 and the avoidance surface 113, does not need to perform the reciprocating action of pressing down and lifting during the welding process of the welding head 100, which directly reduces the mechanical movement cycle, and the welding head 100 seamlessly transitions to the next welding point during continuous rotation without pausing or adjusting the position, thereby significantly improving the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tab 210, thereby greatly improving the process rhythm of the entire battery production line, and at the same time, the acceleration and deceleration of the welding head 100 and the synchronous emission of ultrasound can be performed before the arrival of the battery cell tab 210, effectively avoiding the contact between the welding head 100 and the battery cell tab 210 during the acceleration and deceleration process, greatly reducing the proportion of the weld mark virtual weld area on the battery cell tab 210, maintaining the uniformity and consistency of the weld mark, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tab 210, thereby greatly improving the qualified rate of the final product.

[0054] In some embodiments, 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 the multiple avoidance surfaces 113 are arranged alternately.

[0055] like Figure 1 and Figure 3 As shown, the welding head 100 is designed in an irregular symmetrical manner as a whole, and the number of welding surfaces 111 is the same as the number of avoidance surfaces 113, wherein "multiple" means more than two or more than two. In some embodiments, the number N of welding surfaces 111 / avoidance surfaces 113 satisfies: 2≤N≤9.

[0056] For example, in some embodiments, Figure 1 and Figure 3 As shown, there are three welding surfaces 111 and three avoidance surfaces 113 , and the three welding surfaces 111 and the three avoidance surfaces 113 are arranged alternately, so that the welding work of three battery cell tabs 210 can be completed by rotating the welding head 100 one circle.

[0057] For example, in some other embodiments, Figure 5 As shown, there are two welding surfaces 111 and two avoidance surfaces 113 , and the two welding surfaces 111 and the two avoidance surfaces 113 are alternately arranged, so that the welding work of two battery cell tabs 210 can be completed by rotating the welding head 100 one circle.

[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 the four avoidance surfaces 113 are alternately arranged, so that the welding work of four battery cell tabs 210 can be completed by rotating the welding head 100 one circle.

[0059] The welding head 100 provided in the embodiment of the present application, through the structural design of the staggered arrangement of the above-mentioned multiple welding surfaces 111 and the multiple avoidance surfaces 113, can achieve that the welding head 100 can complete the welding work of multiple battery cell tabs 210 within one rotation cycle, thereby improving production efficiency.

[0060] In some embodiments, Figure 1-Figure 2 As shown, the welding surface 111 is provided with textures 112 .

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

[0062] The pattern 112 may include, but is not limited to, trapezoidal block patterns, straight line patterns, mesh pattern, spiral pattern, wavy pattern, dot pattern or other irregular patterns, etc., which are not limited here.

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

[0064] Among them, Figure 4As shown, taking the pattern 112 designed as a 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 the embodiment of the present application can increase the actual contact area between the welding surface 111 and the battery cell tab 210 through the design of the above-mentioned texture 112, which helps to transfer heat and pressure more evenly, promote the melting and flow of the battery cell tab 210 material on the welding surface 111, improve the fusion effect and welding strength, and thus further improve the welding quality.

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

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

[0068] like Figure 1 and Figure 5-Figure 6 As shown, the connecting shaft 120 is connected between the driving mechanism of the welding device and the welding head body 110 as a transmission mechanism. In other words, the driving mechanism of the welding device is dynamically connected to the connecting shaft 120, and the driving mechanism drives the connecting shaft 120 to rotate around the axial direction, thereby driving the welding head body 110 to rotate around the rotation axis. The axial direction of the connecting shaft 120 is colinear 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, a pin hole, etc. One end of the connecting shaft 120 is designed to be a shape that matches the connection interface of the welding head body 110, such as a thread, a pin, etc. The connecting shaft 120 is tightly connected to the welding head body 110 by rotation or insertion, and the other end of the connecting shaft 120 is connected to the driving 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 made into one piece through casting, forging or precision machining. Specifically, part of the connecting shaft 120 is directly embedded in the design of the welding head body 110 and becomes an integral part thereof. The integrated connecting shaft 120 is connected to the driving 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 elastic material, such as spring steel, rubber, etc. One end of the connecting shaft 120 is fixedly connected to the welding head body 110, and the other end is connected to the driving mechanism of the welding device through an elastic element (such as a spring, rubber pad, etc.). The elastic connecting shaft 120 can absorb and alleviate the impact and vibration generated during the welding process.

[0072] In other embodiments, the connecting shaft 120 can also be designed as a structure with adjustable angle, such as realizing multi-degree-of-freedom adjustment through a universal joint, a ball joint, etc. 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, and the adjustment mechanism can be controlled manually or automatically.

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

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

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

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

[0077] The welding head 100 provided in the embodiment of the present application is designed with the avoidance surface 113 being a plane shape. When there is no battery cell tab 210 at the welding station during the material change time, the plane avoidance surface 113 can reduce the contact with other parts of the welding head 100 or the machine frame to avoid unnecessary wear. At the same time, the design of the plane avoidance surface 113 is relatively simple, easy to process and manufacture, and can meet the welding requirements of battery cell tabs 210 of different specifications and shapes. By adjusting the width and position of the avoidance surface 113, various welding conditions can be flexibly responded to.

[0078] In some embodiments, Figure 5 As shown, the avoidance surface 113 is in an arc shape.

[0079] In this embodiment, if Figure 5 As shown, the avoidance surface 113 may include a main surface 1131 and a connecting surface 1132, the connecting surface 1132 is connected between the main surface 1131 and the welding surface 111, the main surface 1131 and the connecting surface 1132 are both arc surfaces, the center of curvature of the main surface 1131 and the center of curvature of the connecting surface 1132 are respectively located on both sides of the entire avoidance 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 only include a continuous arc surface.

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

[0082] For example, in some embodiments, 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 the embodiment of the present application is designed with the avoidance surface 113 being in an arc shape, so that the arc-shaped avoidance surface 113 corresponds to the arc-shaped welding surface 111, forming a continuous and smooth transition, which can also provide greater convenience during maintenance and cleaning. At the same time, during the rotation process of the welding head 100, it can smoothly bypass the battery cell tab 210 that has been welded or to be welded, reducing direct collision and interference with the battery cell tab 210. This helps to reduce damage to the welding head 100 and deformation of the battery cell tab 210, and improves the stability and reliability of welding.

[0084] It should be noted that, in addition to the above-mentioned plane shape and arc shape, the avoidance surface 113 can also be other types of surfaces, such as a sawtooth shape, a wave shape or any irregular shape, which is not limited here.

[0085] The present application also discloses a welding device for welding a battery cell tab 210 .

[0086] In some embodiments, Figure 6-Figure 8 As shown, the welding device comprises: a welding head 100 as any one of the above-mentioned ones.

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

[0088] It should be noted that the welding device is not limited to the above-mentioned ultrasonic flying roll welding device, but can also include an ultrasonic horizontal welder, an ultrasonic wedge rod welder, a laser welder, a laser welder, a cast welder or a tongue-type battery cell tab 210 welding device, etc., which is not limited here.

[0089] The welding device provided in the embodiment of the present application, through the setting of the above-mentioned welding head 100, does not need to perform the reciprocating action of pressing down and lifting during the welding process, which directly reduces the mechanical movement cycle, and the welding head 100 seamlessly transitions to the next welding point during continuous rotation without pausing or adjusting the position, thereby significantly improving the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tab 210, thereby greatly improving the process rhythm of the entire battery production line, and at the same time, the acceleration and deceleration of the welding head 100 and the synchronous emission of ultrasound can be performed before the arrival of the battery cell tab 210, effectively avoiding the contact between the welding head 100 and the battery cell tab 210 during the acceleration and deceleration process, greatly reducing the proportion of the weld mark virtual weld area on the battery cell tab 210, maintaining the uniformity and consistency of the weld mark, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tab 210, thereby greatly improving the qualified rate of the final product.

[0090] In some embodiments, Figure 6-Figure 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 arranged opposite to each other.

[0091] In this embodiment, if Figure 6-Figure 8As shown, each pair of welding heads 100 may include two welding heads 100 arranged against each other. During welding, the battery cell tab 210 may 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 may 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 may correspond one to one, and the multiple avoidance surfaces 113 of the two welding heads 100 may correspond one to one.

[0092] The welding device provided in the embodiment of the present application has a structural design in which the working surfaces of the two welding heads 100 arranged in pairs are arranged relative to each other, so that the mass distribution of the welding heads 100 is uniform and the vibration form is better, which is beneficial 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 device further includes: a transmission device.

[0094] like Figure 3 and Fig. 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 weld 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 avoidance surface 113 when the welding head 100 rotates, and 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 linear or curved. Specifically, the transmission device can include but is not limited to a conveyor belt, a chain conveyor system, a robotic arm, a slide rail system, a turntable conveyor, a roller conveyor system, a lifting platform, an AGV (Automated Guided Vehicle) or a RGV (Rail Guided Vehicle), etc., and is not limited here.

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

[0097] In actual implementation, Figure 3 , Figure 7 and Fig. 9 For example, the transmission route of the transmission device is linear transmission, and the transmission direction of the transmission device is Figure 6The processing direction of the middle battery cell 200 and the rotation direction of the welding head 100 are designed to match the processing direction of the battery cell 200. The rotation direction of the welding head 100 of the upper mold is opposite to the rotation direction of the welding head 100 of the lower mold. The radius R2 of the virtual arc between the two ends of the avoidance 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 at a standard rotation speed V0, and the ultrasonic generator is activated at the same time, and ultrasonic energy is transmitted to the contact surface of the battery cell tab 210 through the welding head 100. Specifically, the head end of the welding surface 111 first contacts the welding starting point of the battery cell tab 210, and after the welding head 100 rotates to the center angle corresponding to the arc with the weld mark length H as the arc length and the radius R1 of the welding surface 111 as the radius, the battery cell tab 210 completes ultrasonic welding. At this time, the end of the welding surface 111 contacts the welding end point of the battery cell tab 210, and the welding head 100 continues to rotate. After the welding head 100 rotates to the center angle corresponding to the arc with the distance W between the weld marks of the battery cell 200 as the arc length and the radius R2 of the avoidance surface 113 as the radius, the head end of the next welding surface 111 contacts the welding starting point of the next battery cell tab 210, and the subsequent stroke of the welding head 100 repeats the aforementioned actions, which will not be repeated here.

[0098] Welding beat Radius R1 of welding surface 111 = radius of virtual arc

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

[0100] The weld mark length H satisfies: 20mm≤H≤200mm, and the distance W between weld marks satisfies: 20mm≤W≤200mm.

[0101] Specifically, the weld mark length H can be 20 mm, 65.78 mm, 100 mm, 125.4 mm, 188.786 mm, 200 mm or other values ​​between 20 mm and 200 mm, which is not limited here.

[0102] The distance W between the weld marks may be 20 mm, 86.32 mm, 100 mm, 138.5 mm, 192.183 mm, 200 mm or other values ​​between 20 mm and 200 mm, and is not limited here.

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

[0104] Specifically, the radius R1 of the welding surface 111 may be 15 mm, 31.63 mm, 60 mm, 83.1 mm, 92.854 mm, 100 mm or other values ​​between 15 mm and 100 mm, which is not limited here.

[0105] The welding device provided in the embodiment of the present application, through the setting of the above-mentioned transmission device, transmits the battery cells 200 to be welded to the welding station one by one. 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 the production efficiency. At the same time, the welding head 100 can be accurately docked with the welding mark of the battery cell tab 210 without the need for additional adjustment or positioning steps, thereby improving the welding accuracy and efficiency.

[0106] The present application also discloses a welding system for welding a battery cell tab 210 .

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

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

[0109] In actual implementation, Fig.10 As shown, the welding system may also include a battery cell 200 detection system, which 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 battery cell 200 to detect whether there are defects on the surface of the battery cell 200, such as dents, scratches, contamination or other irregularities. At the same time, the position and alignment of the battery cell tab 210 are detected to ensure correct positioning during subsequent welding or other processing. The battery cell 200 detection system feeds back the detection results to the control system, and the control system can issue corresponding control instructions based on the detection results to decide whether to perform welding operations on the battery cell tab 210.

[0110] The welding system provided in the embodiment of the present application significantly improves the continuity and operating efficiency of the ultrasonic pre-welding of the battery cell tab 210 through the setting of the above-mentioned welding device, thereby greatly improving the process rhythm of the entire battery production line, and at the same time greatly reduces the proportion of the weld mark and the virtual weld area on the battery cell tab 210, thereby optimizing the welding quality of the ultrasonic pre-welding of the battery cell tab 210, thereby greatly improving the qualified rate of the final product. In addition, the efficient welding device cooperates with the precise control system to achieve high-precision and high-efficiency welding of the battery cell tab 210, realize the high degree of automation of the welding system, and improve product quality and production efficiency.

[0111] In some embodiments, Figure 9-10 As shown, the control system is configured to, when it is determined that the offset △L between the actual position of the next battery cell 200 to be welded and the reference position is less than the target value, adjust the rotation speed V0 of the welding head 100; when it is determined that the offset △L between the actual position of the next battery cell 200 to be welded and the reference position is not less than the target value, control the welding head 100 to decelerate to reset, and control the transmission device to transmit the next battery cell 200 to be welded to the waste discharge station.

[0112] In actual implementation, Figure 9-10 As shown, after the battery cell 200 to be welded arrives at the loading position through the conveying device, the battery cell 200 detection system takes a photo of the battery cell 200 to be welded, and determines whether the offset △L 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. In the case where the offset △L 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, and the control system can derive the speed adjustment value V1 according to the calculation formula, and the welding head 100 adjusts from the standard speed V0 to the speed V1 through the acceleration a, and then continues to adjust back to the standard speed V0 through the acceleration a, thereby the welding head 100 makes up for the defect of the offset △L, and finally the welding head 100 can arrive at the welding station together with the battery cell 200 to be welded. When the offset △L between the actual position of the battery cell 200 to be welded and the reference position is greater than or equal to the target value, that is, the actual position of the battery cell 200 to be welded exceeds the correctable limit, the battery cell 200 detection system feeds back an NG signal (i.e., a fail signal) to the control system, and the control system controls the welding head 100 to decelerate to stop, and at the same time, the battery cell 200 to be welded enters the waste discharge station. When the machine is shut down and restarted, the position of the next battery cell 200 to be welded needs to be adjusted to the detection position, and the end of the welding surface 111 of the welding head 100 returns to the welding end point of the last battery cell pole ear 210 that has been welded, and then starts. The welding head 100 and the next battery cell 200 to be welded are both accelerated at an acceleration a, and are simultaneously accelerated to a standard speed V0 at the welding station to achieve matching of welding action and position.

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

[0114] It should be noted that the battery cells 200 to be welded at the waste discharge station need to be periodically reloaded, that is, the above-mentioned loading and testing steps need to be repeated, which will not be repeated here.

[0115] The welding system provided in the embodiment of the present application, through the logic design of the correction function configured in the above-mentioned control system, 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, which can effectively reduce the risk of empty welding or poor welding caused by poor incoming materials, thereby improving the accuracy and stability of welding, and automatically processing battery cells 200 with excessive offsets can reduce manual intervention and downtime, thereby improving the production efficiency of the entire welding system, and timely transmitting battery cells 200 with excessive offsets to the waste discharge station for processing can prevent unqualified products from entering subsequent processes, thereby reducing scrap rate and production costs.

[0116] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0117] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

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

[0119] In the description of the present application, “plurality” means two or more.

[0120] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0121] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0122] Other structures of ... according to the embodiments of the present application, such as ... and ..., and operations are known to ordinary technicians in the field and will not be described in detail here.

[0123] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

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

Claims

1. A welding head for welding a battery cell tab, characterized in that: include: 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 an avoidance surface, the welding surface is arc-shaped, and the distance from the avoidance surface to the rotation axis except the end is less than the radius of the welding surface.

2. The welding head according to claim 1, characterized in that: There are multiple welding surfaces and multiple avoidance surfaces, and the multiple welding surfaces and the multiple avoidance surfaces are staggered.

3. The welding head according to claim 1, characterized in that: The welding surface is provided with textures.

4. The welding head according to claim 1, characterized in that: Also includes: A connecting shaft, the welding head body is connected to the connecting shaft.

5. The welding head according to any one of claims 1 to 4, characterized in that: The avoidance surface is a plane type.

6. The welding head according to any one of claims 1 to 4, characterized in that: The avoidance surface is in an arc shape.

7. A welding device for welding a battery cell tab, characterized in that: include: A welding head as claimed in any one of claims 1 to 6.

8. The welding device according to claim 7, characterized in that: 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.

9. The welding device according to claim 7 or 8, characterized in that: Also includes: The transmission device has multiple transmission stations for placing battery cells to be welded, and the distance between the weld 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.

10. A welding system for welding a battery cell tab, characterized in that: include: The welding device according to any one of claims 7 to 9; A control system, when the welding device includes a transmission device, the control system is used to control the welding head and the transmission device.

11. The welding system according to claim 10, characterized in that 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; 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 reset, and control the transmission device to transmit the next battery cell to be welded to the waste discharge station.

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