Cylindrical battery, battery apparatus, electric apparatus, processing method, and necking device

Abstract

A cylindrical battery (102), a battery apparatus (100), an electric apparatus, a processing method, and a necking device (200), relating to the technical field of batteries. The cylindrical battery (102) comprises a housing (1) and an end cover (2). At least one end in the axial direction of the housing (1) is formed as an open end (1a); and the end cover (2) covers the open end (1a), the end cover (2) is connected to the housing (1) by means of a weld mark (3), the weld mark (3) surrounds the end cover (2) in the circumferential direction of the housing (1), and the weld mark (3) retracts inwards in the radial direction of the housing (1) within a cylindrical surface (S) where an outer peripheral surface (1c) of the housing (1) is located.

Description

Cylindrical batteries, battery devices, electrical devices, processing methods and necking equipment

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202510361445.0, filed on March 25, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a cylindrical battery, battery device, power supply device, processing method, and necking equipment. Background Technology

[0004] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. The development of battery technology requires consideration of multiple design factors simultaneously. For example, how to improve the energy density and reliability of cylindrical battery cells is one of the important research directions in the battery field. Summary of the Invention

[0005] This application provides a cylindrical battery, a battery device, an electrical device, a processing method, and a necking device, which helps to balance the reliability and energy density of the cylindrical batteries after assembly.

[0006] In a first aspect, embodiments of this application provide a cylindrical battery, including a housing and an end cap, wherein at least one end of the housing in the axial direction is formed as an open end; the end cap is disposed on the open end and is connected to the housing by a solder joint, the solder joint surrounds the end cap in the circumferential direction of the housing, and the solder joint is recessed in the radial direction of the housing within the cylindrical surface of the outer circumferential surface of the housing.

[0007] In the above technical solution, by setting the solder mark to be radially recessed within the cylindrical surface of the outer circumference of the casing, there is no outward protrusion at the connection between the casing and the end cap. This eliminates the need to reduce creepage risk by increasing the center-to-center distance between adjacent cylindrical cells, thus achieving a better balance between reliability and energy density after the cylindrical cells are assembled. Furthermore, it reduces the risk of external physical damage to the solder mark, improves the connection reliability between the casing and the end cap, and consequently enhances the reliability of the cylindrical cells. Moreover, a reserved space can be formed between the solder mark and the cylindrical surface, allowing for the accommodation of other material layers and reducing or eliminating the portion of these material layers protruding beyond the cylindrical surface, thus mitigating the problem of increased outer diameter caused by the addition of other material layers.

[0008] In some embodiments, the radial inward dimension of the solder mark relative to the cylindrical surface gradually increases along the direction from the housing to the end cap in the axial direction of the housing.

[0009] In the above technical solution, the inward shrinkage dimension gradually increases along the axial direction from the shell to the end cap, indicating that the outer diameter of the solder joint gradually decreases along the axial direction from the shell to the end cap. This makes the outer diameter of the solder joint relatively large at the connection position with the shell, thereby reducing or eliminating the steps and stress formed at the junction of the outer circumference of the shell and the solder joint due to the inward shrinkage of the solder joint, and thus improving the reliability of the connection between the shell and the end cap through the solder joint.

[0010] In some embodiments, the outer contour of the solder mark on the axial section of the cylindrical battery includes a curved segment.

[0011] In the above technical solution, by setting the outer contour line of the solder mark to include a curved segment, the solder mark can at least partially resist external pressure and vibration, reduce the risk of solder mark damage caused by stress concentration and other factors, thereby improving the connection strength between the end cap and the housing, and thus improving the reliability of the cylindrical battery and the battery assembly.

[0012] In some embodiments, on the axial section of the cylindrical battery, the outer contour line of the solder mark includes a slanted segment, one end of which is connected to the housing, and the other end is inclined toward the direction of the end cap along a direction that gradually approaches the central axis of the housing.

[0013] In the above technical solution, by setting the outer contour line of the solder mark to include the oblique line segment, the solder mark is easy to process and form, which facilitates the processing and manufacturing of cylindrical batteries.

[0014] In some embodiments, on the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The inner contour line of the solder mark includes a first contour segment connected between the shell connection point and the maximum melting point of the solder mark. The first contour segment is divided into a first segment and a second segment arranged sequentially from the shell connection point to the maximum melting point. The first segment convexes outward relative to the second segment.

[0015] In the above technical solution, since the first contour segment of the solder stamp is constructed in the form of a protrusion from the shell connection point to the maximum melting point, the connection between the solder stamp and the shell is more reliable, which helps to improve the reliability of the welding connection between the shell and the end cap.

[0016] In some embodiments, the connection point between the first segment and the second segment is located at the center of the length of the first contour segment.

[0017] In the above technical solution, by setting the connection between the first segment and the second segment at the center of the length of the first contour segment, it is shown that the lengths of the first segment and the second segment can be relatively close. This makes the connection between the solder and the shell more reliable and helps to improve the reliability of the welding connection between the shell and the end cap.

[0018] In some embodiments, on the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The point on the outer contour line of the solder mark that is radially opposite to the maximum melting point of the solder mark is the dividing point. The outer contour line includes a second contour segment connecting the cap connection point and the dividing point. In the axial direction of the housing along the direction from the housing to the end cap, the inward dimension of the second contour segment relative to the cylindrical surface along the radial direction of the housing gradually increases.

[0019] In the above technical solution, by processing the second contour segment of the solder mark into a radially increasing inner dimension relative to the cylindrical surface, it is beneficial to realize that the solder mark is processed into a form that is recessed within the cylindrical surface of the outer circumference of the shell.

[0020] In some embodiments, on the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The point on the outer contour line of the solder mark that is radially opposite to the maximum melting point of the solder mark is the dividing point. The outer contour line includes a third contour segment connecting the shell connection point and the dividing point. In the axial direction of the housing along the direction from the housing to the end cap, the inward dimension of the third contour segment relative to the cylindrical surface along the radial direction of the housing gradually increases.

[0021] In the above technical solution, by processing the third contour segment of the solder stamp into a radially increasing inner dimension relative to the cylindrical surface, a space can be reserved on the radially outer side of the third contour segment, namely the space between the third contour segment and the cylindrical surface. This reserved space can be used to accommodate other material layers, such as material layers with insulating, heat-insulating, and corrosion-resistant properties to protect the solder stamp. Since these material layers are at least partially housed in the reserved space, the portion of these material layers protruding beyond the cylindrical surface can be reduced, thereby improving the problem of increased outer diameter caused by the installation of these material layers.

[0022] In some embodiments, the radial indentation of the boundary point relative to the shell connection point is a first dimension D1, and the radial indentation of the cover connection point relative to the boundary point is a second dimension D2, where D2 > D1 ≥ 0 μm.

[0023] In the above technical solution, by setting D2>D1≥0μm, it is shown that the radial shrinkage dimension of the relative cylindrical surface of the third contour segment is relatively small, and the radial shrinkage dimension of the relative cylindrical surface of the second contour segment is relatively large. In this way, the connection reliability between the solder mark and the shell can be better guaranteed, and the connection strength between the shell and the end cap can be improved.

[0024] In some embodiments, the axial distance between the dividing point and the shell connection point is a first distance L1, and the axial distance between the dividing point and the cover connection point is a second distance L2, where L1 > L2.

[0025] In the above technical solution, by setting L1>L2, the connection reliability between the solder mark and the shell can be better guaranteed, and the connection strength between the shell and the end cap can be improved.

[0026] In some embodiments, the end cap includes an edge portion and a central portion, the edge portion overlapping the axial side of the opening end of the housing, the central portion extending into the opening end and having an interference fit with the opening end, and the housing and the edge portion forming a solder mark by side welding.

[0027] In the above technical solution, since the central part extends into the open end and is interference-fitted with the open end, the pre-assembly of the shell and the end cap is reliable, which is conducive to subsequent stable welding. In the subsequent side welding process, the two can be effectively welded together, resulting in a high yield rate and fewer defects such as cracks and shrinkage cavities in the weld. This improves the reliability of the connection between the end cap and the shell, forming a tighter seal. When gas or pressure changes occur inside the battery due to charging and discharging, this tight seal can more effectively prevent gas leakage or electrolyte leakage, maintaining the stability of the internal environment of the cylindrical battery.

[0028] In some embodiments, the maximum penetration depth of the solder mark along the radial direction of the shell is H, and the wall thickness of the shell is E, where 1.2E≥H≥0.7E; the wall thickness of the edge portion at the point of maximum penetration depth of the solder mark directly opposite the axial direction of the shell is L3, where 2E≥L3≥0.5E.

[0029] In the above technical solution, by limiting 1.2E≥H≥0.7E and 2E≥L3≥0.5E, the solder mark can effectively connect the shell and the end cap. Under the premise of meeting the welding requirements, the end cap will not occupy too much space in the axial direction of the shell, which is conducive to the miniaturization of the end cap and improves the energy density of the cylindrical battery pack.

[0030] In some embodiments, the cylindrical battery further includes a protective layer, the protective layer including a first covering portion covering the periphery of the solder mark, at least a portion of the first covering portion being radially recessed within the cylindrical surface.

[0031] In the above technical solution, by setting a protective layer, the solder marks can be protected from the periphery, thereby improving the connection reliability between the shell and the end cap.

[0032] In some embodiments, a portion of the first covering portion protrudes radially beyond the cylindrical surface, and the radial protrusion height does not exceed 150 micrometers.

[0033] In the above technical solution, the increase in diameter caused by the portion of the first covering part protruding outside the cylindrical surface has a negligible impact on the energy density of the cylindrical battery pack, thus better ensuring the energy density of the cylindrical battery pack. Moreover, when the thickness of the first covering part is fixed, by having a portion of the first covering part protrude outside the cylindrical surface, the inner shrinkage size of the solder can be reduced, thereby improving the reliability of connecting the shell and the end cap through the solder.

[0034] In some embodiments, the protective layer includes a second covering portion located axially on the side of the end cap away from the housing and covering the end cap and / or solder marks, the second covering portion being connected to the first covering portion.

[0035] In the above technical solution, by setting the protective layer to include both the second covering part and the first covering part, the protective layer has a larger coverage area, thereby reducing the positional accuracy when setting the protective layer, ensuring the protection effect on the solder stamp, reducing the processing difficulty of the protective layer, and improving the processing efficiency.

[0036] In some embodiments, the protective layer includes a third covering portion that covers the periphery of the housing and is connected to the first covering portion.

[0037] In the above technical solution, by setting the protective layer, a third covering part is also included. The third covering part can be used to form protection for at least part of the outer peripheral surface of the shell. Moreover, by setting the protective layer to include both the third covering part and the first covering part, the protective layer has a larger coverage area, thereby reducing the positional accuracy when setting the protective layer. While ensuring the protection effect on the solder stamp, the processing difficulty of the protective layer is reduced and the processing efficiency is improved.

[0038] In some embodiments, the cylindrical battery further includes a protective film, which is a pre-formed film and covers the periphery of the casing. The area covered by the protective film is called the encapsulation area, and the area covered by the protective layer is called the coating area. The coating area is located at one end of the encapsulation area along the axial direction of the casing.

[0039] In the above technical solution, the reliability of the cylindrical battery can be improved by setting a protective film to protect the outer peripheral surface of the casing.

[0040] In some embodiments, on the axial section of the cylindrical battery, the radial distance between the outer contour line of the protective film and the outer contour line of the protective layer in the casing does not exceed 150 micrometers.

[0041] The above technical solution can better control the outer diameter of the cylindrical battery, so as to ensure the energy density of the cylindrical battery pack.

[0042] In some embodiments, the housing is a nickel-plated housing, and the protective layer is a rust-proof layer.

[0043] In the above technical solution, by setting the protective layer as a rust-proof layer, the solder stamp can be protected against rust, thereby improving the reliability of the connection between the casing and the end cap through the solder stamp and enhancing the reliability of the cylindrical battery.

[0044] In some embodiments, the anti-rust layer is at least one of a UV adhesive printing layer, an ink coating layer, and a metal plating layer.

[0045] In the above technical solutions, the protective layer can be flexibly selected, is easy to process, and can achieve a good rust prevention effect.

[0046] In some embodiments, the diameter to height ratio of the cylindrical battery is: 46mm / 80mm; or 46mm / 95mm; or 46mm / 120mm.

[0047] Secondly, embodiments of this application also provide a battery device, including a cylindrical battery of any of the above-described schemes.

[0048] In the above technical solution, since the cylindrical battery of the present application embodiment is adopted, and the solder mark of the cylindrical battery of the present application is recessed radially inward along the shell within the cylindrical surface of the outer peripheral surface of the shell, the reliability and energy density of the cylindrical battery pack can be well balanced, thereby improving the performance of the battery device.

[0049] Thirdly, embodiments of this application also provide an electrical device, including a battery device according to any of the above-described solutions.

[0050] In the above technical solution, the improved performance of the battery device is beneficial to improving the power consumption performance of the electrical device.

[0051] Fourthly, embodiments of this application also provide a method for processing a cylindrical battery, used to process a cylindrical battery according to any of the above-mentioned schemes. The processing method includes the steps of: providing a housing and an end cap, wherein at least one end of the housing in the axial direction is formed as an open end; covering the open end with the end cap; welding the housing and the end cap from the side of the housing so that the housing and the end cap are connected by a weld mark around the end cap in the circumferential direction of the housing to form a housing unit; and performing a necking treatment on the axial end of the housing unit with the weld mark so that the weld mark is radially recessed within the cylindrical surface of the outer circumferential surface of the housing.

[0052] In the above technical solution, by reducing the diameter of the shaft end with the solder mark on the housing unit, the solder mark is radially recessed within the cylindrical surface of the outer circumference of the housing. On the one hand, this solves the problem of the outer diameter being too large at the solder mark, allowing for a better balance between reliability and energy density after the cylindrical battery pack is assembled. On the other hand, the reduction treatment targets the solder mark formed after the housing and end cap are welded together, meaning that the solder mark that causes the outer diameter to be too large is directly treated. This ensures more directly and effectively that the solder mark is radially recessed within the cylindrical surface of the outer circumference of the housing. Furthermore, since the housing and end cap are side-welded, the welding operation is convenient, and the connection strength and sealing of the weld are good, which helps to improve the overall reliability of the cylindrical battery.

[0053] In some embodiments, the step of reducing the diameter of the shaft end with solder marks on the housing unit specifically includes: pressing the shaft end with solder marks on the housing unit to reduce the diameter.

[0054] In the above technical solution, the narrowing is achieved by directly extruding the weld mark. The weld mark is only a physical change in shape, and there is no loss or change in the material of the weld mark. Therefore, the connection strength and sealing performance between the shell and the end cap can be well guaranteed.

[0055] In some embodiments, the step of extruding the shaft end of the housing unit with solder marks to perform a necking process specifically includes: simultaneously applying necking extrusion force to a plurality of locations spaced apart circumferentially along the housing at the shaft end, and causing the plurality of locations where the extrusion force is applied to move synchronously and in the same direction along the circumferential direction of the housing.

[0056] In the above technical solution, by simultaneously applying necking extrusion force at multiple circumferentially spaced positions along the shell end of the shaft, and ensuring that these multiple points of applied extrusion force are synchronously and in the same direction along the shell circumference, the uniformity of force distribution on the shaft end of the shell unit in the circumferential direction during the necking process is improved. This reduces the possibility of shaft end deformation or damage due to uneven local force distribution, thereby helping to maintain the structural reliability and sealing of the solder joint, and reducing problems such as electrolyte leakage caused by improper necking during the use of cylindrical batteries. Furthermore, since the necking process is performed simultaneously at multiple positions, the processing cycle can be shortened, and production costs can be reduced.

[0057] In some embodiments, the step of pressing the shaft end of the housing unit with a solder mark to perform a necking process specifically includes: providing a force-applying head with a force-applying surface; positioning the force-applying head with the force-applying surface facing the shaft end, and tilting the force-applying surface in a direction gradually away from the central axis of the housing along the direction from the end cap to the housing; and pushing the force-applying head axially along the housing to press the shaft end by the force-applying surface.

[0058] In the above technical solution, by driving the force-applying head with the aforementioned inclined force-applying surface to feed axially along the housing unit, the necking extrusion pressure can be applied evenly, continuously, and smoothly to the weld. The weld undergoes uniform and continuous plastic deformation under the extrusion pressure, thereby reducing the possibility of weld damage due to unstable extrusion pressure, ensuring the structural strength of the weld after necking, and guaranteeing the reliability of the connection between the housing and the end cap. Furthermore, by controlling the inclination angle of the force-applying surface, the degree and shape of the necking can be precisely controlled, and by adjusting the inclination angle, different necking effects can be achieved for products of different sizes, thus meeting different processing requirements and improving processing flexibility.

[0059] In some embodiments, prior to the step of narrowing the welded shaft end of the housing unit, the method further includes: applying radial clamping forces at a plurality of circumferentially spaced locations on the outer periphery of the housing unit, the radial clamping forces pointing radially toward the interior of the housing; and applying an axial support force to the axial end of the housing unit away from the end cap, the axial support force pointing axially toward the end cap.

[0060] In the above technical solution, by applying radial clamping forces at multiple circumferentially spaced positions on the outer periphery of the housing unit, the outer periphery of the housing unit is stably clamped during the necking process to prevent the housing unit from rotating or radially displacing during the necking process. Furthermore, by applying axial support force to the end of the housing unit away from the end cap in the axial direction, stable axial support is provided for the housing unit during the necking process to prevent axial displacement of the housing unit due to the necking extrusion force, thereby ensuring that the necking process can be carried out smoothly and reliably.

[0061] In some embodiments, after the step of narrowing the shaft end with solder marks on the housing unit, the method further includes: covering the housing unit with a protective layer such that the protective layer at least covers the solder marks.

[0062] In the above technical solution, by covering the outer casing unit with a protective layer, the protective layer can at least cover the solder marks, which can effectively protect the solder marks, thereby extending the connection reliability and sealing performance of the solder marks, and thus improving the reliability of the cylindrical battery.

[0063] In some embodiments, the step of coating the housing unit with a protective layer specifically involves coating the housing unit with a protective layer by UV adhesive printing.

[0064] In the above technical solution, the protective layer can be a UV adhesive printing layer, which has a rust-proof protective function, thereby extending the reliability and sealing of the solder joint, and thus improving the reliability of the cylindrical battery. The UV adhesive printing layer has a long service life and is easy to process.

[0065] In some embodiments, a protective layer is applied to the outside of the housing unit, such that the protective layer covers the solder marks and also covers at least the edge position of the shaft end on the axial side away from the housing.

[0066] The aforementioned technical solution allows for a larger coverage area of ​​the protective layer, thereby reducing the positional accuracy required when setting it. This ensures effective protection of the solder joints while reducing the processing difficulty and improving efficiency. Furthermore, extending the protective layer to the edge of the shaft end away from the housing effectively protects these vulnerable areas. These edge locations are susceptible to external forces such as friction and impact during the use and installation of cylindrical batteries; therefore, the additional protective layer provides protection, extends the lifespan of the cylindrical battery, and improves its reliability.

[0067] In some embodiments, a protective layer is applied to the outer surface of the housing unit, such that the protective layer covers the solder marks and also covers the outer peripheral surface of the housing.

[0068] The above technical solution allows the protective layer to have a large coverage area, thereby reducing the positional accuracy required when setting the protective layer. This ensures effective protection of the solder joints while reducing the processing difficulty and improving efficiency. Furthermore, extending the protective layer to the outer circumference of the casing enhances the overall protective capability of the cylindrical battery. As a key structural component of the cylindrical battery, the outer circumference of the casing is susceptible to various external factors during use, transportation, and storage, such as scratches, impacts, and corrosion. The protective layer effectively reduces these damages, extends the battery's lifespan, and thus improves its reliability and safety.

[0069] In some embodiments, a protective film is applied to the outer periphery of the housing. The protective film is a pre-formed film, and the area covered by the protective film is called the coating area. The area covered by the protective layer is called the coating area. The coating area is located at one end of the coating area along the axial direction of the housing.

[0070] In the above technical solution, by covering the casing unit with a protective film and a protective layer, multiple protections are achieved for the casing unit, improving the reliability of the cylindrical battery. Moreover, by using a protective film to cover the outer periphery of the casing, it is not necessary to cover the outer periphery of the casing with the protective layer at the same time as the solder joint, thereby saving material for the protective layer and improving the processing efficiency of the protective layer.

[0071] In some embodiments, the end cap includes an edge portion and a central portion, and the step of placing the end cap on the open end specifically includes: overlapping the edge portion with the axial side of the open end of the housing; and extending the central portion into the open end and interfering with the open end.

[0072] In the above technical solution, since the central part extends into the open end and is interference-fitted with the open end, the pre-assembly of the shell and the end cap is reliable, which is conducive to subsequent stable welding. In the subsequent side welding process, the two can be effectively welded together, resulting in a high yield rate and fewer defects such as cracks and shrinkage cavities in the weld. This improves the reliability of the connection between the end cap and the shell, forming a tighter seal. When gas or pressure changes occur inside the battery due to charging and discharging, this tight seal can more effectively prevent gas leakage or electrolyte leakage, maintaining the stability of the internal environment of the cylindrical battery.

[0073] Fifthly, this application also provides a necking device for necking the shaft end of a cylindrical workpiece. The necking device includes: a clamping device, a necking device, a feed drive device, and a rotary drive device. The clamping device is used to clamp the workpiece, and the space occupied by the workpiece clamped by the clamping device is the workpiece space. The two axial sides of the workpiece space are a first side and a second side, respectively, and the central axis of the workpiece space is a reference line. The necking device includes a force-applying head, which is located on the first side and includes a force-applying surface for necking the shaft end of the workpiece. The distance between the force-applying surface and the reference line gradually increases along the direction from the first side to the second side. The feed drive device drives at least one of the force-applying head and the clamping device to perform a feed movement along the extension direction of the reference line, so that the force-applying surface squeezes the shaft end of the workpiece to achieve necking. The rotary drive device drives at least one of the force-applying head and the clamping device to rotate around the reference line.

[0074] In the above technical solution, when the workpiece is clamped by the clamping device, the feed drive device and the rotary drive device can perform driving operations respectively, so that the shaft end of the workpiece can be gradually squeezed by the force-applying surface. Under the squeezing action of the force-applying surface, the shaft end of the workpiece can gradually shrink in diameter along the extension direction of the reference line. That is, the outer diameter of the shaft end of the workpiece gradually shrinks along the extension direction of the reference line, or in other words, the radial shrinkage of the shaft end of the workpiece gradually increases from the second side to the first side, without any sudden step-like shrinkage. This makes the structural strength of the shrinkage part of the workpiece reliable, and the shrinkage degree of the workpiece is uniform throughout the entire circumference, which is conducive to further improving the shrinkage quality. Furthermore, by setting a rotary drive device to drive at least one of the force-applying head and clamping device to rotate around a reference line, axial feeding can be performed while rotating, so that the extrusion force can be gradually applied to the shaft end of the workpiece, and the amount of retraction applied to the shaft end of the workpiece can also gradually increase. This avoids the workpiece being damaged by a large amount of retraction acting directly on the shaft end of the workpiece. It can also avoid the problem of ineffective retraction due to the hardness of the workpiece end, such as the large wall thickness of the opening end of the shell, or the end cap being welded to the shell. This can improve the applicability of the retraction process.

[0075] In some embodiments, the rotary drive device includes: a rotating base and a rotary drive mechanism, wherein a force-applying head is disposed on the rotating base to rotate synchronously with the rotating base around a reference line, and the rotary drive mechanism is connected to the rotating base to drive the rotating base to rotate around the reference line.

[0076] In the above technical solution, the rotary drive device can drive the force-applying head to rotate around the reference line through the rotating seat and the rotary drive mechanism. During the workpiece is narrowed, it is not necessary for the workpiece to rotate around the reference line, thereby simplifying the clamping device.

[0077] In some embodiments, there are multiple force-applying heads, which are spaced apart along the direction surrounding the reference line. When the rotating seat rotates, it drives the multiple force-applying heads to rotate synchronously and in the same direction around the reference line.

[0078] In the above technical solution, during the necking process, multiple force-applying heads can rotate synchronously with the rotating seat. At this time, the multiple force-applying heads can synchronously and in the same direction along the circumference of the workpiece to simultaneously squeeze the axial end of the workpiece. This improves the uniformity of force on the workpiece during the necking process, helps reduce circumferential torsional deformation of the workpiece during necking, and thus improves the necking quality. Furthermore, since multiple circumferential points are squeezed simultaneously, the necking efficiency is improved. In addition, by setting multiple force-applying heads, the axial end of the workpiece being necked can be radially limited. Simultaneously, since the force-applying surface is inclined to the reference line, the multiple force-applying heads can also axially limit the axial end of the workpiece being necked, thus eliminating the need for mechanisms to apply radial and axial clamping forces at that end, thereby simplifying the necking equipment.

[0079] In some embodiments, the necking device includes: a roller base, a force-applying head being a rotating roller and rotatably mounted on the roller base, the outer peripheral surface of the rotating roller forming the force-applying surface.

[0080] In the above technical solution, by setting the force-applying head as a rotating roller, and the friction between the rotating roller and the workpiece being rolling friction, the frictional force generated during the necking process is reduced, thereby reducing wear between the rotating roller and the workpiece, extending the service life of the rotating roller, improving the structural reliability of the workpiece at the necking point, and reducing the cutting action of the force-applying head on the workpiece, reducing chip generation, and mitigating problems such as product short circuits caused by chip generation, thus improving product reliability. Furthermore, because a rotary drive device is provided and the force-applying head is a self-rotating roller, there are two relative motions between the roller and the workpiece: revolution and rotation. This method of necking, driven by the combined revolution and rotation, using an inclined force-applying surface to press against the area to be necked, effectively achieves necking regardless of the hardness of the area to be necked.

[0081] In some embodiments, the rotating roller is in the shape of a cone.

[0082] In the above technical solution, since the rotating roller is in the shape of a cone, when the axis of the rotating roller is parallel to the central axis of the workpiece space, the distance between the force application surface and the reference line can be gradually increased in the direction of the extension of the reference line from the force application head to the clamping part. Therefore, when setting the rotating roller, it is not necessary to adjust the angle between the axis of the rotating roller and the central axis of the workpiece space to control the tilt angle of the force application surface, thereby reducing the installation difficulty of the rotating roller.

[0083] In some embodiments, the rotating roller is cylindrical.

[0084] In the above technical solution, since the self-rotating roller is cylindrical, its structure is simple and easy to process, its production cost is low, and its installation is foolproof.

[0085] In some embodiments, the rotating roller is detachably mounted on the roller base.

[0086] In the above technical solution, the necking requirements of different workpieces can be adapted by replacing the rotating roller, thereby expanding the applicability of the necking equipment. Furthermore, as a consumable component in the necking process, the rotating roller frequently comes into contact with the workpiece and bears pressure and wear. By making the rotating roller detachably mounted on the roller base, it is easy to inspect, clean, repair, or replace it, thereby extending the service life of the necking equipment and reducing maintenance costs.

[0087] In some embodiments, the narrowing device includes a first adjustment mechanism connected to the roller base for adjusting the tilt angle of the axis of the rotating roller relative to the reference line.

[0088] In the above technical solution, by adjusting the angle of the roller base through the first adjustment mechanism, the tilt angle of the force application surface of the rotating roller can be adjusted. Thus, the tilt angle of the axis of the rotating roller relative to the baseline can be flexibly adjusted according to the different shrinking requirements of the workpiece, so that the shrinking equipment can perform shrinking processing on different workpieces, meet different shrinking requirements, and improve the applicability of the shrinking equipment.

[0089] In some embodiments, the first adjustment mechanism includes an adjustment seat, a connecting shaft, and a locking member. The roller base is rotatably mounted on the adjustment seat via the connecting shaft. The locking member is used to lock the relative angle between the roller base and the adjustment seat. The axis of the connecting shaft intersects with a reference line.

[0090] In the above technical solution, by unlocking the locking element, the relative angle between the roller base and the adjusting seat can be adjusted. This allows for adjustment of the tilt angle of the rotating roller's axis according to different necking requirements, thereby expanding the applicability of the necking equipment. Locking the locking element ensures that the adjusted relative angle between the roller base and the adjusting seat remains stable, reducing the possibility of angle changes due to vibration or external interference during operation, thus improving the working stability of the necking equipment. Furthermore, the first adjusting mechanism in the above structural form is simple in structure, low in cost, and only mechanically adjustable, making the adjustment operation simple and easily meeting adjustment requirements.

[0091] In some embodiments, the rotary drive device includes: a rotating seat and a rotary drive mechanism, wherein the roller base is disposed on the rotating seat to rotate synchronously with the rotating seat around a reference line, and the rotary drive mechanism is connected to the rotating seat to drive the rotating seat to rotate around the reference line.

[0092] In the above technical solution, the rotary drive device can drive the force-applying head to rotate around the reference line through the rotating seat and the rotary drive mechanism. During the workpiece is narrowed, it is not necessary for the workpiece to rotate around the reference line, thereby simplifying the clamping device.

[0093] In some embodiments, the narrowing device includes a second adjustment mechanism connected between the rotating seat and the roller base for adjusting the position of the roller base relative to the rotating seat along a reference line.

[0094] In the above technical solution, by setting a second adjustment mechanism, the radial position of the force-applying head can be adjusted, thereby enabling the necking process for workpieces with different outer diameters, thus increasing the applicability of the necking equipment.

[0095] In some embodiments, the force-applying head is a wedge-shaped block, and the inclined surface of the wedge-shaped block constitutes the force-applying surface.

[0096] In the above technical solution, by setting wedge blocks, which do not need to rotate relative to the rotating roller, the overall structure of the necking device can be simplified, reducing production costs. Furthermore, all surfaces of the wedge blocks, except for the force-applying surface, can be constructed as flat surfaces, facilitating fixation and improving the stability and reliability of the necking process. Moreover, the multiple wedge blocks spaced apart along the direction surrounding the reference line allow multiple force-applying heads to rotate synchronously and in the same direction around the reference line when the rotating seat rotates. This also enables radial and axial positioning of the workpiece shaft end and improves the problem of workpiece torsional deformation.

[0097] In some embodiments, the force-applying head is a constricted ring, which is coaxially arranged with the baseline, and the inner circumferential surface of the constricted ring is the force-applying surface.

[0098] In the above technical solution, the necking ring is coaxially set with the baseline, allowing it to surround the axial end of the workpiece to be necked. This enables the necking ring to apply uniform extrusion force across the entire circumference of the workpiece during the necking process, thereby improving the stability and stress uniformity of the workpiece and reducing the risk of workpiece deformation due to uneven force application, thus increasing the necking yield. Furthermore, since the force application head is a necking ring, compared to multiple rotating rollers, only one necking ring is needed to complete the necking process. This simplifies installation and debugging, and facilitates disassembly and replacement, helping to reduce operational difficulty and manufacturing costs.

[0099] In some embodiments, the feed drive device includes a radial feed drive mechanism for driving the force-applying head to feed in a direction perpendicular to the reference line.

[0100] In the above technical solution, by setting a radial feed drive mechanism, the force application head is driven to feed in a direction perpendicular to the baseline, so that the feed direction of the force application head includes the radial direction along the workpiece. This makes the drive control of the necking more flexible and can meet more necking requirements.

[0101] In some embodiments, the feed drive device includes an axial feed drive mechanism for driving the force-applying head to feed along the extension direction of the reference line.

[0102] In the above technical solution, the axial feed drive mechanism drives the force application head to move axially. During the workpiece narrowing process, the workpiece does not need to move axially, which simplifies the clamping device.

[0103] In some embodiments, the rotary drive device includes: a rotating seat, with a force-applying head disposed on the rotating seat to rotate synchronously with the rotating seat around a reference line; and an axial feed drive mechanism including a first feed drive mechanism disposed between the rotating seat and the force-applying head to drive the force-applying head to feed relative to the rotating seat along the extension direction of the reference line.

[0104] In the above technical solution, since the first feed drive mechanism is located between the rotating seat and the force-applying head, it drives the force-applying head to feed relative to the rotating seat along the extension direction of the reference line, so that the entire rotating seat does not need to be fed along the axial direction, thereby reducing the driving force.

[0105] In some embodiments, the rotary drive device includes: a rotating seat, with a force-applying head disposed on the rotating seat to rotate synchronously with the rotating seat around a reference line; and an axial feed drive mechanism including a second feed drive mechanism connected to the rotating seat to drive the rotating seat and the force-applying head to feed synchronously along the extension direction of the reference line.

[0106] In the above technical solution, since the second feed drive mechanism is connected to the rotating seat and is not located between the rotating seat and the force-applying head, the connection between the rotating seat and the force-applying head can be simplified, and it is convenient to set an adjustment mechanism between the rotating seat and the force-applying head to adjust the position or angle of the force-applying head. It also facilitates the routing of the second feed drive mechanism.

[0107] In some embodiments, the force-applying surface extends in a straight line in the direction from the first side and the second side.

[0108] In the above technical solution, since the force-applying surface extends in a straight line from the first side and the second side, the processing of the force-applying surface can be simplified, the structural complexity of the force-applying head can be reduced, and the installation position of the force-applying head can be easily positioned when installing the force-applying head, thereby improving assembly efficiency.

[0109] In some embodiments, the angle γ between the force-applying surface and the reference line is 1°-30°.

[0110] In the above technical solution, since the angle between the force-applying surface and the reference line is greater than or equal to 1°, it is convenient for the force-applying surface to squeeze the end of the workpiece to reduce the opening during axial feeding. Furthermore, since the angle between the force-applying surface and the reference line is less than or equal to 30°, and the angle between the force-applying surface and the central axis is small, it is beneficial to make the transition between the reduced opening part and the unreduced opening part of the workpiece smooth, thus ensuring the structural strength of the reduced opening part.

[0111] In some embodiments, the dimension W of the force-applying surface in the extension direction of the baseline is 5mm-30mm.

[0112] In the above technical solution, since the size of the force-applying surface in the extension direction of the baseline is greater than or equal to 5mm, the size of the force-applying surface in the extension direction of the baseline will not be too small, which is conducive to the cooperation with the workpiece and has a sufficient area to squeeze and compress the workpiece, which is conducive to adapting to various shrinking requirements. Furthermore, since the size of the force-applying surface in the extension direction of the baseline is less than or equal to 30mm, the size of the force-applying surface in the extension direction of the baseline will not be too large, thereby reducing the manufacturing cost of the force-applying head, reducing the cost of the shrinking equipment, and saving the space occupied by the force-applying head, which is conducive to the compact and miniaturized design of the shrinking equipment.

[0113] In some embodiments, the clamping device includes an end face clamping mechanism, the end face clamping mechanism including a first clamping member, the first clamping member being disposed on a second side, the abutting surface of the first clamping member being perpendicular to the reference line for abutting the axial end face of the workpiece away from the force-applying head along the axial direction.

[0114] In the above technical solution, the end of the shaft, far from the force-applying head, is held only by the end face along the axial direction, which reduces the concentricity requirement and facilitates quick clamping. Moreover, the end face holding the workpiece can counteract the axial force applied by the force-applying head, thereby preventing the workpiece from falling out of the clamping position and ensuring that the necking process can be carried out smoothly.

[0115] In some embodiments, the end face clamping mechanism further includes a first clamping drive mechanism, which is connected to the first clamping member to drive the end face clamping device to move along the extension direction of the reference line.

[0116] In the above technical solution, after clamping, the first clamping drive mechanism can be used to push the first clamping member to move the workpiece along the extension direction of the baseline to approach the narrowing device. Conversely, when clamping the workpiece, the first clamping drive mechanism can be used to push the first clamping member away from the narrowing device along the extension direction of the baseline, thus providing more space for workpiece clamping operations. Furthermore, in some embodiments, the first clamping drive mechanism can be used instead of the axial feed drive mechanism.

[0117] In some embodiments, the clamping device includes: a foolproof protection mechanism, which is arranged along a reference line with the end face clamping mechanism and is used to limit the end face clamping mechanism in the extension direction along the reference line.

[0118] In the above technical solution, the risk of collision between the workpiece and the narrowing device can be avoided when the first clamping drive mechanism drives the first clamping member to move beyond the preset value, thereby protecting the workpiece.

[0119] In some embodiments, the clamping device includes a radial clamping mechanism, which includes a second clamping member. The second clamping members are multiple and spaced apart on the periphery of the workpiece space in a direction surrounding a reference line. The abutting surface of the second clamping member is parallel to the reference line and is used to abut the outer peripheral surface of the workpiece radially.

[0120] In the above technical solution, the second clamping member applies radial clamping force to multiple circumferentially spaced positions on the outer periphery of the workpiece, thereby firmly clamping the outer periphery of the workpiece during the necking process to prevent the workpiece from rotating or radially displacing during the necking process, ensuring that the necking process can be carried out smoothly and improving the necking quality.

[0121] In some embodiments, the radial clamping mechanism includes a second clamping drive mechanism connected to a second clamping member for driving the second clamping member to move radially along the workpiece space.

[0122] In the above technical solution, the second clamping member can be driven by the second clamping drive mechanism to achieve automatic clamping, and it can adapt to clamping workpieces with different outer diameters.

[0123] In some embodiments, the clamping device and the narrowing device are arranged in a horizontal direction perpendicular to the direction of gravity, so that the central axis of the workpiece space is perpendicular to the direction of gravity.

[0124] The above technical solution can avoid the risk of damage to the device below if the upper device is not supported stably, and can avoid the arrangement of the necking device and the clamping device along the direction of gravity. It also facilitates assembly and debugging. Attached Figure Description

[0125] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0126] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0127] Figure 2 is an exploded view of a battery device provided in some embodiments of this application;

[0128] Figure 3 is a schematic diagram of the structure of a cylindrical battery provided in some embodiments of this application;

[0129] Figure 4 is an exploded view of the cylindrical battery structure provided in some embodiments of this application;

[0130] Figure 5 is a partial cross-sectional view of a cylindrical battery provided in some embodiments of this application;

[0131] Figure 6 is a partial enlarged view of a cylindrical battery provided in some embodiments of this application;

[0132] Figure 7 is a partially enlarged metallographic view of the axial section of a cylindrical battery provided in some embodiments of this application;

[0133] Figure 8 is an enlarged schematic diagram of the solder marks shown in Figure 6;

[0134] Figure 9 is a partially enlarged view of the axial cross-section of a cylindrical battery provided in some embodiments of this application;

[0135] Figure 10 is a partially enlarged view of the axial cross-section of a cylindrical battery provided in some other embodiments of this application;

[0136] Figure 11 is a partially enlarged view of the axial section of a cylindrical battery provided in some embodiments of this application;

[0137] Figure 12 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0138] Figure 13 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0139] Figure 14 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0140] Figure 15 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0141] Figure 16 is a schematic diagram of some embodiments of this application using a force-applying head to compress the orifice;

[0142] Figure 17 is a schematic diagram of another embodiment of this application using a force-applying head to compress the orifice;

[0143] Figure 18 is a schematic diagram of a force-applying head extruding a compression port in some embodiments of this application;

[0144] Figure 19 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0145] Figure 20 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0146] Figure 21 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0147] Figure 22 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application;

[0148] Figure 23 is a schematic diagram of the structure of a necking device provided in some embodiments of this application;

[0149] Figure 24 is an enlarged view of point B of the necking device shown in Figure 23;

[0150] Figure 25 is a schematic diagram of a necking device provided in some embodiments of this application;

[0151] Figure 26 is a partial structural schematic diagram of a necking device provided in some embodiments of this application;

[0152] Figure 27 is an enlarged view of point C of the necking device shown in Figure 26;

[0153] Figure 28 is a schematic diagram of a necking device provided in some embodiments of this application;

[0154] Figure 29 is a schematic diagram of the structure of the self-rotating roller shown in Figure 28;

[0155] Figure 30 is a schematic diagram of a necking device provided in some embodiments of this application;

[0156] Figure 31 is a schematic diagram of the structure of the self-rotating roller shown in Figure 30;

[0157] Figure 32 is a schematic diagram of a necking device provided in some embodiments of this application;

[0158] Figure 33 is a schematic diagram of a necking device provided in some embodiments of this application;

[0159] Figure 34 is a schematic diagram of a necking device provided in some embodiments of this application;

[0160] Figure 35 is a schematic diagram of a necking device provided in some embodiments of this application;

[0161] Figure 36 is a schematic diagram of a necking device provided in some embodiments of this application;

[0162] Figure 37 is a schematic diagram of a necking device provided in some embodiments of this application.

[0163] Reference numerals: Vehicle 1000; Battery assembly 100; Housing 101; First housing section 1011; Second housing section 1012; Cylindrical battery 102; Casing component 1021; Casing unit Q; Electrode component 1022; Terminal component 1023; Casing 1; First direction F1; Second direction F2; Central axis L; Open end 1a; Closed end 1b; Outer peripheral surface 1c; Cylindrical surface S; End cap 2; Edge portion 21; Central portion 22; Weld mark 3; Outer contour line of weld mark 31; Oblique line segment 31b; Curved segment 31a; Casing connection point P1; Cover connection point P2; Maximum melt depth point P3; Dividing point P4; Second contour segment 311; Third contour segment 312; Inner contour line 32; First contour segment 321; First segment 3211; Second segment 3212; Connection 321; Protective layer 4; Outer contour line of protective layer 45; First covering part 41; Second covering part 42; Third covering part 43; Protective film 5; Outer contour line of protective film 55; Narrowing device 200; Clamping device 6; End face clamping mechanism 61; First clamping member 611; First clamping drive mechanism 612; Stop member 613; Foolproof protection mechanism 62; Radial clamping mechanism 63; Second clamping member 631; Second clamping drive mechanism 632; Workpiece space 65; First side 651; Second side 652; Narrowing device 7; Force applying head 71; Force applying surface 711; Rotating roller 71a; Axis of rotating roller L3; Wedge block 71b; Narrowing ring 71c; Roller base 72; First adjusting mechanism 73; Adjusting seat 731; Connecting shaft 732; Axis of connecting shaft L4; Locking member 733; Second adjusting mechanism 74; Angle adjusting mechanism 75; Radial adjusting mechanism 76; Feed drive device 8; Axial feed drive mechanism 81; First feed drive mechanism 81a; Second feed drive mechanism 81b; Radial feed drive mechanism 82; Rotary drive device 9; Reference line L5; Rotary seat 91; Rotary drive mechanism 92; Workpiece 300; Center axis of workpiece L2; Controller 400; Motor 500. Detailed Implementation

[0164] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0165] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0166] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0167] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to direct connection or indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0168] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0169] It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative examples and should not constitute any limitation on this application.

[0170] In this application, "multiple" means two or more, including two.

[0171] In this application, the cylindrical battery may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, or solid-state batteries, etc., and the embodiments of this application are not limited to this.

[0172] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more cylindrical batteries to provide higher voltage and capacity. Exemplarily, the battery device may include a housing for encapsulating one or more cylindrical batteries, or one or more battery modules, the housing preventing liquids or other foreign matter from affecting the charging or discharging of the cylindrical batteries.

[0173] A cylindrical battery includes a casing, electrode components, and an electrolyte (which may be a solid electrolyte layer located between the positive and negative electrodes in a solid-state battery). The electrode components include at least one electrode assembly, which, along with the electrolyte, is housed within the casing. The electrode assembly includes a positive electrode, a negative electrode, and a separator (this structure may be omitted in solid-state batteries). Cylindrical batteries primarily function by the movement of metal ions between the positive and negative electrodes.

[0174] The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the positive current collector without the positive active material layer protrudes from the positive current collector with the positive active material layer. The positive current collector without the positive active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0175] The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the negative current collector without the negative active material layer protrudes from the negative current collector with the negative active material layer. The negative current collector without the negative active material layer serves as the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc.

[0176] The separator can be made of PP, polypropylene, PE, polyethylene, etc. The electrode assembly mentioned in the embodiments of this application has a wound or stacked structure.

[0177] The materials used for the housing components include, but are not limited to, aluminum, steel, composite metal, or other materials resistant to electrolyte corrosion.

[0178] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. The development of battery technology requires consideration of multiple design factors simultaneously. For example, improving the energy density and reliability of cylindrical battery cells is an important research direction in the battery field.

[0179] In the production of cylindrical batteries, there are generally two sealing methods: grooved sealing and laser welding sealing. Laser welding sealing has a higher volumetric energy density than grooved sealing for the same formulation, so it is usually chosen. However, laser welding requires no gap between the end cap and the casing, and the weld reinforcement formed during the cooling of the molten pool results in the diameter of the finished cylindrical battery at the weld being larger than the design requirement. When multiple cylindrical batteries are assembled, the larger diameter at the weld causes the spacing between adjacent cylindrical batteries to be less than the minimum safe creepage distance, leading to reliability issues. To solve this problem, the center-to-center spacing between adjacent cylindrical batteries needs to be increased. However, this reduces the total number of cylindrical batteries that can be accommodated per unit space, resulting in a decrease in the energy density of the battery pack. Therefore, it is currently difficult to simultaneously achieve both reliability and energy density after cylindrical battery assembly.

[0180] In view of this, this application proposes a cylindrical battery. The cylindrical battery casing includes a housing and an end cap. At least one end of the housing is formed as an open end in the axial direction. The end cap is disposed on the open end and connected to the housing by a solder joint, that is, the housing and the end cap are connected by welding. Thus, a solder joint is formed at the connection between the housing and the end cap. The solder joint surrounds the end cap circumferentially along the housing and is radially recessed within the cylindrical surface of the outer circumference of the housing. Therefore, by setting the solder joint to be recessed within the cylindrical surface of the outer circumference of the housing, there is no outward protrusion problem at the connection between the housing and the end cap. This reduces the risk of creepage while ensuring energy density, and allows for a better balance between reliability and energy density after the cylindrical battery pack is assembled.

[0181] The technical solutions described in the embodiments of this application are applicable to cylindrical batteries, battery devices containing cylindrical batteries, and electrical devices using battery devices.

[0182] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0183] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0184] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 is equipped with a battery device 100, which can be located at the bottom, head, or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0185] The vehicle 1000 may also include a controller 400 and a motor 500. The controller 400 is used to control the battery device 100 to supply power to the motor 500, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0186] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0187] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a cylindrical battery 102 and a housing 101 for housing the cylindrical battery 102. The housing 101 can have various shapes, such as a cylindrical housing, a cuboid housing, etc. However, this application is not limited to this. In some other embodiments of this application, the battery device 100 may not include the housing 101.

[0188] The housing 101 can have various structural forms. For example, referring to FIG2, in some embodiments, the housing 101 may include a first housing portion 1011 and a second housing portion 1012, which overlap each other, and together define a receiving space for accommodating the cylindrical battery 102. A sealing material may also be provided at the connection point between the first housing portion 1011 and the second housing portion 1012 to achieve a sealed connection between them.

[0189] For example, referring to Figure 2, the second box portion 1012 can be a hollow structure with an opening on one side, and the first box portion 1011 is in the form of a lid that can be closed onto the opening side of the second box portion 1012. Alternatively, both the first box portion 1011 and the second box portion 1012 can be hollow structures with an opening on one side, with the opening side of the first box portion 1011 closing onto the opening side of the second box portion 1012, thus forming a box 101 with a accommodating space.

[0190] In the battery device 100, there are multiple cylindrical batteries 102. These cylindrical batteries 102 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that some of the cylindrical batteries 102 are connected in series while others are connected in parallel. The multiple cylindrical batteries 102 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple cylindrical batteries 102 is housed within the housing 101. Alternatively, the multiple cylindrical batteries 102 can first be connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 101. In some embodiments, the multiple cylindrical batteries 102 can be electrically connected through a busbar component to achieve parallel, series, or mixed configurations.

[0191] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the structure of a cylindrical battery 102 provided in some embodiments of this application, and Figure 4 is an exploded view of the structure of a cylindrical battery 102 provided in some embodiments of this application. The cylindrical battery 102 includes a housing component 1021, an electrode component 1022, and a terminal component 1023. The electrode component 1022 and the electrolyte are both disposed within the housing component 1021. The housing component 1021 is cylindrical in shape, and the terminal component 1023 is disposed at at least one of the two axial ends of the housing component 1021.

[0192] For example, the housing component 1021 is insulated from the electrode component 1023, and only one electrode component 1023 is provided on the housing component 1021. In this case, the positive output terminal of the electrode component 1022 can be electrically connected to the electrode component 1023, and the negative output terminal of the electrode component 1022 can be electrically connected to the housing component 1021; or, the negative output terminal of the electrode component 1022 can be electrically connected to the electrode component 1023, and the positive output terminal of the electrode component 1022 can be electrically connected to the housing component 1021.

[0193] For example, the housing component 1021 is insulated from the pole component 1023, and two pole components 1023 are provided on the housing component 1021. In this case, the positive output terminal of the electrode component 1022 can be electrically connected to one pole component 1023, and the negative output terminal of the electrode component 1022 can be electrically connected to the other pole component 1023.

[0194] Please refer again to Figures 3 and 4. The housing component 1021 includes a housing 1 and an end cap 2. At least one axial end of the housing 1 is formed as an open end 1a, and the end cap 2 is disposed on the open end 1a. That is, the housing 1 is cylindrical and is open at one or both axial ends, and the end cap 2 is disposed on the open axial end of the housing 1 to seal the open axial end of the housing 1. For example, in some embodiments, the end cap 2 can partially extend into the open end 1a, thereby improving the stability and reliability of the fit between the two and improving the sealing performance after the connection. In this case, the fit between the housing 1 and the end cap 2 is not limited, and may include, but is not limited to, interference fit, transition fit, clearance fit, etc.

[0195] Wherein, the central axis L of the housing 1 serves as the central axis of the housing component 1021, the central axis of the housing component 1021 serves as the central axis of the cylindrical battery 102, the central axis L of the housing 1 extends along the first direction F1, the first direction F1 is the axial direction of the housing 1, and at least one of the two ends of the housing 1 in the first direction F1 is open to form an opening end 1a.

[0196] For example, when one axial end of the housing 1 is open to form an open end 1a and the other axial end is closed to form a closed end 1b, only one end cap 2 is needed and it covers the open end 1a of the housing 1. In this case, the electrode post 1023 can be disposed on the closed end 1b of the housing 1 or it can be disposed on the end cap 2. Exemplarily, when the electrode post 1023 is disposed on the closed end 1b of the housing 1, the positive output terminal (or negative output terminal) of the electrode post 1022 is electrically connected to the electrode post 1023, and the negative output terminal (or positive output terminal) of the electrode post 1022 is electrically connected to the end cap 2.

[0197] For example, when both axial ends of the housing 1 are open, forming open ends 1a at both axial ends of the housing 1, two end caps 2 are required, each covering one of the two open ends 1a on the axial sides of the housing 1. In this case, if there is one pole post component 1023, it can be disposed on one of the end caps 2; if there are two pole post components 1023, they can be disposed on the same end cap 2, or they can be disposed on the two end caps 2 on opposite sides, that is, one pole post component 1023 is disposed on each end cap 2.

[0198] Furthermore, it is worth noting that the number of electrode components 1022 is not limited to this. For example, there may be two or more electrode components 1022, and the electrode output terminals (such as positive or negative output terminals) of the electrode components 1022 may be connected to at least two electrode components 1022. In addition, the placement of the electrode components 1022 is not limited to this; the electrical connection position between the electrode output terminals of the electrode components 1022 and the housing component 1021 is also not limited to this.

[0199] Please refer to Figures 5 and 6. Figure 5 is a partial cross-sectional view of a cylindrical battery 102 provided in some embodiments of this application, and Figure 6 is a partial enlarged view of a cylindrical battery 102 provided in some embodiments of this application. The cylindrical battery 102 can have numerous axial sections and numerous cross sections. A cross section refers to the section obtained by cutting the cylindrical battery 102 with a plane perpendicular to the axial direction of the housing 1, and an axial section refers to the section obtained by cutting the cylindrical battery 102 with a plane passing through the central axis L of the housing 1 (i.e., the central axis L of the housing 1 lies within this plane). Therefore, Figure 5 is a partial view of the axial section schematic diagram of the cylindrical battery 102, and Figure 6 is a partial enlarged view of the connection position between the end cap 2 and the housing 1 in the axial section schematic diagram of the cylindrical battery 102 (for example, corresponding to point A circled in Figure 5).

[0200] Referring to Figures 5 and 6, the end cap 2 is connected to the housing 1 via a weld mark 3. That is, the end cap 2 is welded to the housing 1. The welding method between the end cap 2 and the housing 1 is not limited, and may include, but is not limited to, laser welding, ultrasonic welding, a combination of ultrasonic pre-welding and laser welding, resistance welding, pressure welding, brazing, etc. For simplicity, laser welding will be used as an example in the following description.

[0201] The weld mark 3 surrounds the end cap 2 along the circumference of the housing 1. That is, at least a portion of the weld mark 3 is located in the outer peripheral area of ​​the end cap 2 and presents a form surrounding the end cap 2. The phrase "presents a form surrounding the end cap 2" should be understood as continuously surrounding the entire circumference of the housing 1, thereby ensuring a complete connection and seal between the end cap 2 and the housing 1.

[0202] For example, during the processing of the cylindrical battery 102, after the end cap 2 is assembled to the open end 1a of the housing 1, the housing 1 and the end cap 2 can be welded around the circumference of the housing 1 to connect the end cap 2 and the housing 1. The weld marks 3 are formed at the weld joint and surround the end cap 2 around the circumference of the housing 1.

[0203] In related technologies, during the processing of cylindrical batteries, the welding of the casing and end cap can typically be done using either side welding or end welding. Side welding involves welding from the circumference of the casing, where the laser beam can be incident roughly radially. In this case, the weld mark formed by the welding of the casing and end cap is mainly located on the circumference of the casing, meaning at least most of the weld mark can be located in the outer circumference of the end cap and appear to surround it. End welding, on the other hand, involves welding from the axial side of the casing, where the laser beam can be incident roughly axially. In this case, the weld mark formed by the welding of the casing and end cap is mainly located on the axial side of the casing. However, if welding is performed closer to the edge of the end cap, there is also a possibility that a portion of the weld mark may be located in the outer circumference of the end cap and appear to surround it. Therefore, both side welding and end welding can potentially achieve a configuration where "end cap 2 and casing 1 are connected by weld mark 3, with weld mark 3 surrounding end cap 2 circumferentially around casing 1." For simplicity, side welding will be used as an example in the following explanation.

[0204] Please refer again to Figures 5 and 6, and in conjunction with Figure 7, which is a partially enlarged metallographic view of the axial section of a cylindrical battery provided in some embodiments of this application. The solder mark 3 is radially recessed within the cylindrical surface S containing the outer circumferential surface 1c of the housing 1. As described above, the housing 1 is cylindrical; therefore, the outer circumferential surface 1c of the housing 1 can be infinitely extended along the axial direction of the housing 1 (e.g., the first direction F1 shown in Figure 6) to obtain the cylindrical surface S containing the outer circumferential surface 1c of the housing 1, where the cylindrical surface S is a virtual cylindrical surface. Furthermore, the radial directions of the housing 1 can be infinitely numerous, and all are perpendicular to the axial direction of the housing 1 (e.g., the second direction F2 shown in Figure 6 is one of these radial directions).

[0205] The phrase "the solder mark 3 is radially recessed within the cylindrical surface S of the outer circumferential surface 1c of the housing 1" means that the solder mark 3 is located within the area defined by the cylindrical surface S, and there is a gap between the outer contour line 31 of the solder mark 3 and the cylindrical surface S. Thus, in any radial direction of the housing 1, the solder mark 3 will not protrude beyond the cylindrical surface S of the outer circumferential surface 1c of the housing 1. Alternatively, on the axial section of the cylindrical battery 102, the outer contour line 31 of the solder mark 3 does not protrude beyond the side of the cylindrical surface S away from the central axis L of the housing 1. Or, taking the plane containing the cross-section of the cylindrical battery 102 as the projection plane, the outline of the orthographic projection of the cylindrical surface S within this projection plane defines a circular region, and the orthographic projection of the solder mark 3 within this projection plane does not extend beyond this circular region.

[0206] Specifically, when the molten pool formed by welding the casing and end cap cools, it creates weld reinforcement. If the outer diameter of the opening end of the casing matches the outer diameter of the cylindrical surface before welding, the weld mark is prone to protruding beyond the cylindrical surface, resulting in a larger outer diameter at the weld mark. Furthermore, when the casing and end cap are interference-fitted, a portion of the end cap extends into the opening end of the casing, causing outward compression. This results in an increase in the outer diameter of the opening end after assembly, meaning the opening end undergoes expansion deformation. Thus, the outer diameter of the opening end is larger than the outer diameter of the cylindrical surface before welding. Even without weld reinforcement, the weld mark formed after welding will protrude beyond the cylindrical surface, resulting in a larger outer diameter at the weld mark. Because of this larger weld mark diameter, when multiple cylindrical batteries are grouped together, the distance between adjacent cylindrical batteries at the weld will be less than the minimum safe creepage distance. To increase the creepage distance, the center-to-center distance between adjacent cylindrical batteries needs to be increased, but this will reduce the energy density of the assembled cylindrical battery pack.

[0207] In this embodiment, the solder mark 3 is recessed radially inward along the shell 1 within the cylindrical surface S of the outer circumferential surface 1c of the shell 1, so that the solder mark 3 at the connection between the shell 1 and the end cap 2 does not have the problem of outward protrusion, thereby solving the problem of the outer diameter of the solder mark 3 being too large. In this way, it is not necessary to increase the center distance between adjacent cylindrical batteries 102, and the creepage risk at the solder mark 3 can be effectively avoided. Thus, the energy density of the cylindrical batteries 102 after assembly can be improved while ensuring the reliability of the assembled cylindrical batteries 102.

[0208] Furthermore, by setting the solder mark 3 to be radially recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1, a gap is formed between the outer contour line 31 of the solder mark 3 and the cylindrical surface S, thereby creating a reserved space between the solder mark 3 and the cylindrical surface S. This reserved space can accommodate other material layers, such as material layers with rust prevention, insulation, heat insulation, corrosion prevention, and impact resistance, to protect the solder mark 3. Since these material layers are at least partially housed within the reserved space, the portion of these material layers protruding beyond the cylindrical surface S can be reduced or eliminated, thereby improving the problem of increased outer diameter caused by the installation of these material layers.

[0209] For example, when one axial end of the housing 1 is open to form an open end 1a and the other axial end is closed to form a closed end 1b, only one end cap 2 is needed and it covers the open end 1a of the housing 1. At this time, one axial end of the housing 1 has a weld mark 3, which is radially recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1. However, when both axial ends of the housing 1 are open, so that both axial ends of the housing 1 are formed as open ends 1a, two end caps 2 are needed and they cover the two open ends 1a on both sides of the axial direction of the housing 1. At this time, each axial end of the housing 1 has a weld mark 3, and the weld mark 3 at each end is radially recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1.

[0210] In the above technical solution, "inward" is only intended to indicate that the relative positional relationship between the solder mark 3 and the cylindrical surface S is that the solder mark 3 does not protrude from the cylindrical surface S, rather than implying a specific process method. In the embodiments of this application, the method of setting the weld mark 3 to be radially recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1 is not limited. For example, after welding the housing 1 and the end cap 2, the weld mark 3 can be subjected to a necking process, such as by extrusion, to make the weld mark 3 move closer to the central axis L of the housing 1, so that the weld mark 3 after the necking process does not protrude from the cylindrical surface S, thereby solving the problem of the outer diameter of the weld mark 3 being too large. Alternatively, for example, before welding the housing 1 and the end cap 2, the opening end 1a of the housing 1 can be set to have an outer diameter smaller than the outer diameter of the cylindrical surface S, and the outer diameter of the end cap 2 can be set to match the opening end 1a of the housing 1. This provides a space for the weld reinforcement and / or the expansion deformation of the opening end 1a (i.e., the difference between the outer diameter of the cylindrical surface S and the outer diameter of the opening end 1a), so that the weld mark 3 formed after welding the end cap and the housing 1 does not protrude from the cylindrical surface S, thereby solving the problem of the outer diameter of the weld mark 3 being too large.

[0211] In summary, by setting the solder mark 3 to be radially recessed within the cylindrical surface S of the outer circumferential surface 1c of the housing 1, the solder mark 3 at the connection between the housing 1 and the end cap 2 does not bulge outwards, thus solving the problem of excessively large outer diameter at the solder mark 3. This allows for a better balance between reliability and energy density after the cylindrical battery 102 is assembled. Furthermore, a reserved space can be formed between the solder mark 3 and the cylindrical surface S, which can accommodate other material layers, reducing or eliminating the portion of these material layers protruding beyond the cylindrical surface S, thus mitigating the problem of increased outer diameter caused by the addition of other material layers. In addition, since the solder mark 3 is recessed within the cylindrical surface S of the outer circumferential surface 1c of the housing 1, the risk of external physical damage to the solder mark 3 can be reduced. During the installation or transportation of the battery device 100, even if it encounters vibration or slight collision and scratch, the possibility of damage to the solder mark 3 can be reduced because the solder mark 3 is recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1. This ensures the reliability of the connection between the housing 1 and the end cap 2, thereby improving the reliability of the cylindrical battery 102.

[0212] Referring again to Figure 6, in some embodiments, along the direction from the housing 1 to the end cap 2 in the axial direction of the housing 1 (e.g., the first direction F1 shown in Figure 6), the inward dimension T of the solder mark 3 relative to the cylindrical surface S in the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 6) gradually increases. Here, the inward dimension T refers to the distance between the outer contour line of the solder mark 3 and the cylindrical surface S in the radial direction of the housing 1.

[0213] In the above technical solution, the inward dimension T gradually increases along the axial direction of the housing 1 from the housing 1 to the end cover 2, indicating that the outer diameter of the solder mark 3 gradually decreases along the axial direction of the housing 1 from the housing 1 to the end cover 2. This makes the outer diameter of the solder mark 3 relatively large at the connection position with the housing 1, thereby reducing or eliminating the step and stress formed at the junction of the outer peripheral surface 1c of the housing 1 and the solder mark 3 due to the inward shrinkage of the solder mark 3, and thus improving the reliability of connecting the housing 1 and the end cover 2 through the solder mark 3.

[0214] In some embodiments, referring to FIG6, on the axial section of the cylindrical battery 102, the outer contour line 31 of the solder mark 3 may include a curved segment 31a. That is, the outer contour line 31 of the solder mark 3 may be constructed as a curved segment 31a as a whole, or only partially constructed as a curved segment 31a. The curved segment 31a may have a certain curvature or arc, which may be continuous and smooth, or segmented and have a specific shape.

[0215] In the above technical solution, by setting the outer contour line 31 of the solder mark 3 to include the curved segment 31a, the solder mark 3 can at least partially resist external pressure and vibration, reduce the risk of damage to the solder mark 3 due to stress concentration and other factors, thereby improving the connection strength between the end cover 2 and the housing 1, and thus improving the reliability of the cylindrical battery 102 and the battery assembly 100.

[0216] For example, the opening end 1a of the housing 1 can be narrowed before welding the housing 1 and the end cap 2. This way, the weld mark 3 formed after welding can automatically meet the requirement of being narrowed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1, and the outer contour line 31 of the naturally formed weld mark 3 may be at least partially a curved segment 31a. Alternatively, for example, the weld mark 3 can also be narrowed after welding the housing 1 and the end cap 2. This way, by setting the narrowing equipment, at least part of the outer contour line 31 of the weld mark 3 can be processed into a curved segment 31a.

[0217] In some embodiments, referring to Figures 5 and 6, the outer contour line 31 of the solder mark 3 on the axial section of the cylindrical battery 102 may also include a slanted line segment 31b. That is, the outer contour line 31 of the solder mark 3 may be constructed as a slanted line segment 31b as a whole, or the outer contour line 31 of the solder mark 3 may only be partially constructed as a slanted line segment 31b. The slanted line segment 31b is constructed as a straight line that intersects the central axis L of the housing 1 at a certain angle. Specifically, on the axial section of the cylindrical battery 102, one end of the slanted line segment 31b is connected to the housing 1, and the other end of the slanted line segment 31b is inclined towards the end cap 2 along the direction that gradually approaches the central axis L of the housing 1.

[0218] Therefore, by setting the outer contour line 31 of the solder mark 3 to include the aforementioned oblique line segment 31b, the solder mark 31 is easy to process and form, which can reduce the processing difficulty of shrinking the solder mark 3 within the cylindrical surface S of the outer peripheral surface 1c of the housing 1, and also facilitates meeting the requirement that the shrinkage dimension T of the solder mark 3 relative to the cylindrical surface S gradually increases along the radial direction of the housing 1.

[0219] For example, a force-applying head with an inclined force-applying surface (i.e., the force-applying surface is inclined to the central axis L of the housing 1) can be pushed to move along the axial direction of the housing 1 to squeeze the weld mark 3, so that the outer contour line 31 of the weld mark 3 is formed into an oblique line that intersects the central axis L of the housing 1 at a certain angle, and the weld mark 3 is recessed inside the cylindrical surface S where the outer peripheral surface 1c of the housing 1 is located. In the axial direction of the housing 1 (e.g., the first direction F1 shown in FIG. 6) along the direction from the housing 1 to the end cap 2, the requirement that the inward dimension T of the weld mark 3 relative to the cylindrical surface S along the radial direction of the housing 1 gradually increases is met, which is convenient for processing.

[0220] For example, referring to FIG6, on the axial section of the cylindrical battery 102, the outer contour line 31 of the solder mark 3 is composed of a sloping line segment 31b and a curved segment 31a. The curved segment 31a is connected to the side of the sloping line segment 31b away from the housing 1. One end of the sloping line segment 31b away from the curved segment 31a is connected to the housing 1. The other end of the sloping line segment 31b is inclined towards the end cap 2 along the direction gradually approaching the central axis L of the housing 1 and is connected to the curved segment 31a.

[0221] Referring to Figures 6-8, Figure 8 is an enlarged schematic diagram of the solder mark shown in Figure 6. In some embodiments, on the axial section of the cylindrical battery 102, the two endpoints of the outer contour line 31 of the solder mark 3 are the shell connection point P1 connected to the shell 1 and the cap connection point P2 connected to the end cap 2, respectively. The inner contour line 32 of the solder mark 3 includes a first contour segment 321 connecting the shell connection point P1 and the maximum melting point P3 of the solder mark 3. The first contour segment 321 is divided into a first segment 3211 and a second segment 3212 arranged sequentially from the shell connection point P1 to the maximum melting point P3. The first segment 3211 protrudes outward relative to the second segment 3212. That is, the first contour segment 321 is composed of the first segment 3211 and the second segment 3212, and the first segment 3211 protrudes in a direction away from the center of the solder mark 3 relative to the second segment 3212.

[0222] Thus, when observing the first contour segment 321 on the axial section of the cylindrical battery 102, it can be found that the first contour segment 321 is constructed such that it first bulges outward in the direction from the shell connection point P1 to the maximum melting point P3. That is, the bulging part protrudes in the direction away from the center of the solder mark 3 relative to the remaining part of the first contour segment 321. The bulging part is the first segment 3211, and the remaining part is the second segment 3212.

[0223] In the above technical solution, since the first contour segment 321 of the weld mark 3 is constructed in a shape that bulges outward from the shell connection point P1 to the maximum penetration point P3, the connection between the weld mark 3 and the shell 1 is more reliable, which helps to improve the reliability of the welded connection between the shell 1 and the end cap 2. For example, during processing, the weld mark 3 can be pushed in towards the central axis L of the shell 1, so that the first segment 3211 of the first contour segment 321 bulges outward relative to the second segment 3212.

[0224] Please refer again to Figures 6-8. In some embodiments, the connection point 3213 between the first segment 3211 and the second segment 3212 is located at the center of the length of the first contour segment 321. Here, "the center of the length of the first contour segment 321" means that if the length of the first contour segment 321 is divided into three equal parts, the central part occupies the position of the center of the length of the first contour segment 321. Therefore, by setting the connection point 321 between the first segment 3211 and the second segment 3212 at the center of the length of the first contour segment 321, it is shown that the lengths of the first segment 3211 and the second segment 3212 can be relatively close. This makes the connection between the solder mark 3 and the housing 1 more reliable, and helps to improve the reliability of the welding connection between the housing 1 and the end cap 2.

[0225] Please refer again to Figures 6-8. In some embodiments, on the axial section of the cylindrical battery 102, the two endpoints of the outer contour line 31 of the solder mark 3 are the shell connection point P1 connected to the housing 1 and the cap connection point P2 connected to the end cap 2, respectively. The point on the outer contour line 31 of the solder mark 3 that is directly opposite the maximum melting point P3 of the solder mark 3 in the radial direction (e.g., the second direction F2 shown in Figure 8) is the dividing point P4. The outer contour line 31 includes a second contour segment 311 connecting the cap connection point P2 and the dividing point P4. In the axial direction of the housing 1 (e.g., the first direction F1 shown in Figure 8) along the direction from the housing 1 to the end cap 2, the radial inward dimension T of the second contour segment 311 relative to the cylindrical surface S gradually increases.

[0226] Therefore, whether the necking is done before or after welding, it can be done along the direction from the end cap 2 to the housing 1, which facilitates the necking operation and makes it easier to process the weld mark 3 into a form that is recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1. For example, after welding the housing 1 and the end cap 2, when processing the weld mark 3 into a form that is recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1 by pressing the weld mark 3, a force-applying head with an inclined force-applying surface (i.e., the force-applying surface is inclined to the central axis L of the housing 1) can be pushed along the axial direction of the housing 1 from the end cap 2 to the housing 1 to press the weld mark 3. In this way, the radial inward dimension T of the second contour segment 311 relative to the cylindrical surface S gradually increases, thereby facilitating processing.

[0227] Please refer again to Figures 6-8. In some embodiments, on the axial section of the cylindrical battery 102, the two endpoints of the outer contour line 31 of the solder mark 3 are the shell connection point P1 connected to the housing 1 and the cap connection point P2 connected to the end cap 2, respectively. The point on the outer contour line 31 of the solder mark 3 that is directly opposite the maximum melt depth point P3 of the solder mark 3 in the radial direction (e.g., the second direction F2 shown in Figure 8) is the dividing point P4. The outer contour line 31 includes a third contour segment 312 connecting the shell connection point P1 and the dividing point P4. In the axial direction of the housing 1 (e.g., the first direction F1 shown in Figure 8), along the direction from the housing 1 to the end cap 2, the radial inward dimension T of the third contour segment 312 relative to the cylindrical surface S gradually increases. Exemplarily, the third contour segment 312 can be a slanted segment 31b, a curved segment 31a, or a combination of slanted segment 31b and curved segment 31a.

[0228] Therefore, a space can be reserved on the radial outer side of the third profile segment 312, that is, the space between the third profile segment 312 and the cylindrical surface S. This reserved space can be used to accommodate other material layers, such as material layers with anti-rust, insulation, heat insulation, anti-corrosion, and impact resistance to protect the solder mark 3. Since these material layers are at least partially housed in the reserved space, the portion of these material layers protruding beyond the cylindrical surface S can be reduced, thereby improving the problem of the outer diameter increasing due to the setting of these material layers.

[0229] Furthermore, the third contour segment 312 in the above form is also easy to process. For example, after welding the housing 1 and the end cap 2, when the weld mark 3 is processed into a form that is recessed within the cylindrical surface S of the outer peripheral surface 1c of the housing 1 by extruding the weld mark 3, the force-applying head with an inclined force-applying surface (i.e., the force-applying surface is inclined to the central axis L of the housing 1) can be pushed in the axial direction of the housing 1 along the direction from the end cap 2 to the housing 1 to extrude the weld mark 3. In this way, the radial inward dimension T of the third contour segment 312 relative to the cylindrical surface S gradually increases, thereby facilitating processing.

[0230] Please refer again to Figures 6-8. In some embodiments, the dimension by which the dividing point P4 is recessed radially relative to the shell connection point P1 (e.g., the second direction F2 shown in Figure 8) is a first dimension D1, and the dimension by which the cover connection point P2 is recessed radially relative to the dividing point P4 (e.g., the second direction F2 shown in Figure 8) is a second dimension D2, wherein D2 > D1 ≥ 0 μm.

[0231] In the above technical solution, by setting D2>D1≥0μm, it is shown that the radial shrinkage dimension of the relative cylindrical surface S of the third contour segment 312 is relatively small, and the radial shrinkage dimension of the relative cylindrical surface S of the second contour segment 311 is relatively large. In this way, the connection reliability between the solder mark 3 and the shell 1 can be better guaranteed, and the connection strength between the shell 1 and the end cover 2 can be improved.

[0232] Please refer again to Figures 6-8. In some embodiments, the distance between the dividing point P4 and the shell connection point P1 along the axial direction (e.g., the first direction F1 shown in Figure 8) is the first distance L1, and the distance between the dividing point P4 and the cover connection point P2 along the axial direction (e.g., the first direction F1 shown in Figure 8) is the second distance L2, where L1 > L2.

[0233] In the above technical solution, by setting L1>L2, the connection reliability between the solder mark 3 and the housing 1 can be better guaranteed, and the connection strength between the housing 1 and the end cover 2 can be improved.

[0234] Please refer to Figure 6 again. In some embodiments, the end cap 2 includes an edge portion 21 and a central portion 22. The edge portion 21 is disposed around the central portion 22. The edge portion 21 overlaps the axial side of the opening end 1a of the housing 1. The central portion 22 extends into the opening end 1a and is interference-fitted with the opening end 1a. The housing 1 and the edge portion 21 form a weld mark 3 by side welding.

[0235] In the above technical solution, since the central part 22 extends into the opening end 1a and is interference-fitted with the opening end 1a, the pre-assembly of the shell 1 and the end cover 2 is reliable, which is conducive to subsequent stable welding. In the subsequent side welding process, the two can be effectively welded together, resulting in a high yield after welding. Defects such as cracks and shrinkage cavities are not likely to appear in the weld mark 3, thereby improving the reliability of the connection between the end cover 2 and the shell 1 and forming a tighter seal. When gas or pressure changes occur inside the battery due to charging and discharging, this tight seal can more effectively prevent gas leakage or electrolyte leakage, and maintain the stability of the internal environment of the cylindrical battery 102.

[0236] Referring again to Figure 6, in some embodiments, the maximum penetration depth of the solder mark 3 along the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 6) is H, and the wall thickness of the housing is E, where 1.2E ≥ H ≥ 0.7E; the wall thickness of the edge portion 21 at the point P3 directly opposite the maximum penetration depth of the solder mark 3 along the axial direction of the housing 1 (e.g., the first direction F1 shown in Figure 6) is L3, where 2E ≥ L3 ≥ 0.5E. For example, H can be 0.7E, 0.8E, 0.9E, 1.0E, 1.1E, 1.2E, etc., and L3 can be 0.5E, 0.7E, 0.9E, 1.2E, 1.4E, 1.6E, 1.8E, 2.0E, etc.

[0237] Therefore, by limiting 1.2E≥H≥0.7E and 2E≥L3≥0.5E, the solder mark 3 can effectively connect the housing 1 and the end cap 2. Under the premise of meeting the welding requirements, the end cap 2 will not occupy too much space in the axial direction of the housing 1, which is conducive to the miniaturization of the end cap 2 and improves the energy density of the cylindrical battery 102 after assembly.

[0238] For example, 1.1E ≥ L3 ≥ 0.7E, where H can be 0.7E, 0.8E, 0.9E, 1.0E, 1.1E, etc. This allows the solder mark 3 to effectively connect the housing 1 and the end cap 2, and the end cap 2, while meeting welding requirements, does not occupy excessive space in the axial direction of the housing 1, thus facilitating the miniaturization of the end cap 2 and improving the energy density of the cylindrical battery 102 after assembly.

[0239] For example, 1.2H ≥ L3 ≥ 0.5H, where L3 can be 0.5H, 0.7H, 0.9H, 1.0H, 1.1H, 1.2H, etc. This allows the solder mark 3 to effectively connect the housing 1 and the end cap 2, and the end cap 2, while meeting welding requirements, does not occupy excessive space in the axial direction of the housing 1, thus facilitating the miniaturization of the end cap 2 and improving the energy density of the cylindrical battery 102 after assembly.

[0240] Referring to Figure 9, which is a partially enlarged view of the axial section of a cylindrical battery provided in some embodiments of this application, in some embodiments, the cylindrical battery 102 further includes a protective layer 4, which includes a first covering portion 41 that covers the periphery of the solder stamp 3. That is, the first covering portion 41 is located radially outside the solder stamp 3, so that by providing the protective layer 4, the solder stamp 3 can be protected from the periphery, thereby improving the connection reliability between the housing 1 and the end cap 2.

[0241] It is worth noting that the term "covering" in this article refers only to the protective layer 4 being in a covering form, and does not imply any specific process method. Furthermore, the material of the protective layer 4 is not limited and can be selected according to functional requirements. For example, the requirements may include at least one of rust prevention, insulation, heat insulation, corrosion resistance, wear resistance, and impact resistance, thereby providing appropriate protection as needed.

[0242] Referring again to Figure 9, at least a portion of the first covering portion 41 is recessed within the cylindrical surface S along the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 9). That is, there is a gap between the outer contour line 31 of the solder mark 3 and the cylindrical surface S, thereby forming a reserved space between the solder mark 3 and the cylindrical surface S. At least a portion of the first covering portion 41 is located within the reserved space, so that at least a portion of the first covering portion 41 does not protrude from the cylindrical space enclosed by the cylindrical surface S.

[0243] Alternatively, the plane containing the cross-section of the cylindrical battery 102 is taken as the projection plane, and the outline of the orthographic projection of the cylindrical surface S in the projection plane defines a circular region. At least a portion of the orthographic projection of the first covering part 41 in the projection plane is located within the aforementioned circular region, that is, at least a portion of the orthographic projection of the first covering part 41 in the projection plane does not extend beyond the aforementioned circular region.

[0244] Therefore, the space occupied by the first covering portion 41 for protecting the solder mark 3 outside the cylindrical surface S can be reduced or eliminated, thereby improving the problem of the outer diameter increasing due to the provision of the first covering portion 41.

[0245] Referring again to Figure 9, in some embodiments, a portion of the first covering portion 41 protrudes beyond the cylindrical surface S in the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 9), and the protrusion height X in the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 9) does not exceed 150 micrometers. That is, the radial dimension of the portion of the first covering portion 41 protruding beyond the cylindrical surface S is less than or equal to 150 micrometers.

[0246] Therefore, the increase in diameter caused by the portion of the first covering part 41 protruding outside the cylindrical surface S has a negligible impact on the energy density of the cylindrical battery 102 after assembly, thus better ensuring the energy density of the cylindrical battery 102 after assembly. Moreover, when the thickness of the first covering part 41 is fixed, by having a portion of the first covering part 41 protrude outside the cylindrical surface S, the inner dimension of the solder mark 3 can be reduced, thereby improving the reliability of connecting the housing 1 and the end cap 2 through the solder mark 3.

[0247] Please refer again to FIG9. In some embodiments, the protective layer 4 may further include a second covering portion 42, which is located on the side of the end cap 2 away from the housing 1 along the axial direction of the housing 1 (e.g., the first direction F1 shown in FIG9) and covers the end cap 2 and / or the solder mark 3. The second covering portion 42 is connected to the first covering portion 41.

[0248] Therefore, by setting the protective layer 4 to include both the second covering part 42 and the first covering part 41, the protective layer 4 has a larger coverage area, thereby reducing the positional accuracy when setting the protective layer 4. While ensuring the protection effect on the solder mark 3, the processing difficulty of the protective layer 4 is reduced and the processing efficiency is improved.

[0249] Referring to FIG10, FIG10 is a partially enlarged view of the axial section of a cylindrical battery provided in some other embodiments of the present application. In some embodiments, the protective layer 4 further includes a third covering portion 43, which covers the periphery of the housing 1 and is connected to the first covering portion 41.

[0250] Therefore, by providing a third covering part 43 in the protective layer 3, at least a portion of the outer peripheral surface 1c of the housing 1 can be protected by the third covering part 43. Moreover, by providing a protective layer 4 that includes both the third covering part 43 and the first covering part 41, the protective layer 4 has a larger coverage area, thereby reducing the positional accuracy when setting the protective layer 4. While ensuring the protection effect on the solder mark 3, the processing difficulty of the protective layer 4 is reduced and the processing efficiency is improved.

[0251] For example, the protective layer 4 may also include a first covering portion 41, a second covering portion 42, and a third covering portion 43 simultaneously. Thus, the third covering portion 43 can be used to protect at least a portion of the outer peripheral surface 1c of the housing 1. Furthermore, by configuring the protective layer 4 to simultaneously include the third covering portion 43, the second covering portion 42, and the first covering portion 41, the protective layer 4 has a larger coverage area, thereby reducing the positional accuracy required when setting the protective layer 4. This ensures effective protection of the solder mark 3 while reducing the processing difficulty of the protective layer 4 and improving processing efficiency.

[0252] It is worth noting that the extent to which the third covering part 43 covers the shell 1 is not limited. For example, the dimension of the third covering part 43 along the axial direction of the shell 1 is the same as the axial length of the shell 1, so as to completely cover the outer peripheral surface 1c of the shell 1. Or, for example, the dimension of the third covering part 43 along the axial direction of the shell 1 can be smaller than the axial length of the shell 1, so as to cover a part of the outer peripheral surface 1c of the shell 1.

[0253] Furthermore, to protect the casing 1, the third covering portion 43 may not be provided. For example, in some embodiments, referring to FIG11, FIG11 is a partially enlarged view of the axial section of a cylindrical battery provided in some embodiments of this application. The cylindrical battery 102 may also include a protective film 5, which is a pre-formed film covering the periphery of the casing 1. The area covered by the protective film 5 is the encapsulation area, and the area covered by the protective layer 4 is the coating area. The coating area is located at one end of the encapsulation area along the axial direction of the casing 1 (e.g., the first direction F1 shown in FIG11). In the above technical solution, by providing the protective film 5 to protect the outer peripheral surface 1c of the casing 1, the reliability of the cylindrical battery 102 can be improved.

[0254] It is worth noting that the protective film 5 is a pre-formed film, meaning that the protective film 5 has been processed into a thin film form before being wrapped around the housing 1, and then the film is wrapped onto the outer peripheral surface 1c of the housing 1 through an assembly process. The material of the protective film 5 is not limited; for example, the material of the protective film 5 can be selected according to at least one of the requirements of rust prevention, insulation, heat insulation, corrosion prevention, wear resistance, and impact resistance.

[0255] It is worth noting that the extent to which the protective film 5 covers the housing 1 is not limited. For example, the dimension of the protective film 5 along the axial direction of the housing 1 is consistent with the axial length of the housing 1, so as to completely cover the outer peripheral surface 1c of the housing 1. Alternatively, the dimension of the protective film 5 along the axial direction of the housing 1 can also be smaller than the axial length of the housing 1, thereby covering only a portion of the outer peripheral surface 1c of the housing 1. In addition, at the junction of the protective film 5 and the protective layer 4, the protective film 5 can be wrapped with the protective layer 4, thereby further improving the reliability of the cylindrical battery 102.

[0256] Please refer again to Figure 11. In some embodiments, on the axial section of the cylindrical battery 102, the distance between the outer contour line 55 of the protective film 5 and the outer contour line 45 of the protective layer 4 in the radial direction of the housing 1 (e.g., the second direction F2 shown in Figure 9) does not exceed 150 micrometers. This allows for better control of the outer diameter of the cylindrical battery 102, thereby ensuring the energy density of the cylindrical batteries 102 after assembly.

[0257] For example, the distance between the outer contour line 55 of the protective film 5 and the outer contour line 45 of the protective layer 4 in the radial direction of the housing 1 (e.g., the second direction F2 shown in FIG9) can also be zero, that is, the outer contour line 55 of the protective film 5 and the outer contour line 45 of the protective layer 4 can be flush.

[0258] In some embodiments, the housing 1 is a nickel-plated housing, and the protective layer 4 is a rust-proof layer. Therefore, by setting the protective layer 4 as a rust-proof layer, the solder mark 3 can be protected against rust, improving the reliability of the connection between the housing 1 and the end cap 2 via the solder mark 3, and enhancing the reliability of the cylindrical battery 102. Exemplarily, the rust-proof layer can be at least one of a UV adhesive (also known as shadowless adhesive, photosensitive adhesive, or ultraviolet light curing adhesive, which is a type of adhesive that must be cured by ultraviolet light irradiation), an ink coating layer, or a metal plating layer. Thus, the protective layer 4 can be flexibly selected, is easy to process, and can provide a good rust-proof effect.

[0259] The above-described technical solutions of this application can be applied to cylindrical batteries 102 of any size. For example, they can be applied to cylindrical batteries 102 with a diameter-to-height ratio of 46mm / 80mm (i.e., diameter 46mm, height 80mm); or 46mm / 95mm (i.e., diameter 46mm, height 95mm); or 46mm / 120mm (i.e., diameter 46mm, height 120mm), etc. Here, the diameter of the cylindrical battery 102 refers to its outer diameter, and the height of the cylindrical battery 102 refers to its axial height.

[0260] This application also provides a battery device 100, including a cylindrical battery 102 of any of the above-described embodiments. Therefore, since the reliability and energy density of the cylindrical batteries 102 assembled according to this application embodiment can be well balanced, it is beneficial to improve the overall performance of the battery device 100.

[0261] This application also provides an electrical device including a battery device 100 according to any of the above-described embodiments, the battery device 100 being used to provide electrical energy to the electrical device. The electrical device can be any of the aforementioned devices or systems using the battery device 100. Because the performance of the battery device 100 is improved, it is beneficial to enhance the power consumption performance of the electrical device.

[0262] This application also provides a method for processing a cylindrical battery 102. The structural drawings involved in the processing method can be referred to in Figures 3-11 above. In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0263] Referring to Figure 12, which is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of this application, the processing method of the cylindrical battery 102 in the embodiments of this application may include the following steps:

[0264] Step S100: Provide a housing 1 and an end cap 2, wherein at least one axial end of the housing 1 is formed as an open end 1a. The specific structural form of the housing 1 and the end cap 2 can be referred to the above embodiment. For example, one axial end of the housing 1 is open to form an open end 1a, and the other axial end is closed to form a closed end 1b; or, for example, both axial ends of the housing 1 are open, so that both axial ends of the housing 1 are formed as open ends 1a.

[0265] For example, both the housing 1 and the end cap 2 can be made of a material with a certain degree of hardness and strength. This makes it less prone to deformation when the housing 1 or the end cap 2 is subjected to compression or impact, enabling the cylindrical battery 102 to have higher structural strength and improved safety performance. For example, the materials of the housing 1 and the end cap 2 can be selected from various sources, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0266] Step S200: Place the end cap 2 on the open end 1a. The specific fit between the housing 1 and the end cap 2 can be referred to the embodiment above. The housing 1 and the end cap 2 are independent components. The open end 1a is provided on the housing 1, and the end cap 2 covers the open end 1a. The fit between the housing 1 and the end cap 2 may include, but is not limited to, interference fit, transition fit, clearance fit, etc.

[0267] For example, the shape of the end cap 2 can be adapted to the shape of the housing 1, and a portion of the end cap 2 extends into the opening end 1a of the housing 1. For example, the end cap 2 includes an edge portion 21 and a central portion 22, the edge portion 21 being disposed around the central portion 22, the edge portion 21 overlapping the axial side of the opening end 1a of the housing 1, and the central portion 22 extending into the opening end 1a and being interference-fitted with the opening end 1a.

[0268] Step S300: Weld the housing 1 and end cap 2 from the side of the housing 1, so that the housing 1 and end cap 2 are connected by a weld mark 3 around the end cap 2 along the circumference of the housing 1 to form a housing unit Q. That is, the housing 1 and end cap 2 are welded together by side welding (abbreviated as side welding), and the weld mark 3 obtained therefrom is around the end cap 2 along the circumference of the housing 1. That is, at least a portion of the weld mark 3 is located in the outer peripheral area of ​​the end cap 2 and is in the form of surrounding the end cap 2, so that the mating part of the housing 1 and the end cap 2 is connected and sealed, and the housing 1 and the end cap 2 form the housing unit Q.

[0269] It is worth noting that the "shell unit Q" in the statement "shell 1 and end cap 2 are connected by a solder mark 3 around end cap 2 along the circumference of shell 1 to form shell unit Q" includes shell 1, end cap 2, and solder mark 3. Solder mark 3 surrounds end cap 2 along the circumference of shell 1 and connects shell 1 and end cap 2. The shell component 1021 described herein includes shell unit Q, meaning that shell component 1021 can be composed entirely of shell unit Q alone, or shell component 1021 can be composed of shell unit Q and other components. The environment formed inside shell component 1021 can be used to accommodate electrode component 1022, electrolyte, and other components.

[0270] For example, when one axial end of the housing 1 is open to form an open end 1a and the other axial end is closed to form a closed end 1b, after welding the end cap 2 to that end, the resulting housing unit Q includes the housing 1, one end cap 2, and one weld mark 3. In this case, the housing unit Q can serve as a complete housing component 1021. As another example, when both axial ends of the housing 1 are open ends 1a, the end cap 2 can be welded to one end first. The resulting housing unit Q only includes the housing 1, one end cap 2, and one weld mark 3, and cannot serve as a complete housing component 1021. Then, after welding the end cap 2 to the other end, the resulting housing unit Q includes the housing 1, two end caps 2, and two weld marks 3. In this case, the housing unit Q can serve as a complete housing component 1021. Alternatively, in other embodiments, when both axial ends of the housing 1 are open ends 1a, end caps 2 can be welded to both ends simultaneously. The resulting housing unit Q includes the housing 1, two end caps 2, and two weld marks 3. In this case, the housing unit Q can serve as a complete housing component 1021.

[0271] For example, when the end cap 2 includes an edge portion 21 and a central portion 22, the edge portion 21 is disposed around the central portion 22, the edge portion 21 overlaps the axial side of the opening end 1a of the housing 1, the central portion 22 extends into the opening end 1a and is interference-fitted with the opening end 1a, the housing 1 and the end cap 2 are welded from the side of the housing 1 so that the housing 1 and the edge portion 21 form a weld mark 3 by side welding.

[0272] In the above-described processing method for the cylindrical battery 102, the shell 1 and the end cap 2 are connected by side welding, forming a strong and reliable connection between them. Furthermore, the alignment and welding operations of the welding heads are relatively easy to achieve during side welding, which helps optimize the processing flow on the production line, achieve automated production, improve production efficiency, and reduce costs. In addition, during the use of the cylindrical battery 102, when the pressure on the peripheral wall of the shell 1 is less than the pressure on the end cap 2, the side-welded connection can withstand greater pressure, reducing the risk of electrolyte leakage due to connection breakage and improving the sealing performance of the cylindrical battery 102.

[0273] Step S400: The shaft end of the housing unit Q with the weld mark 3 is reduced in diameter, so that the weld mark 3 is radially reduced inward along the housing 1 and within the cylindrical surface S of the outer peripheral surface 1c of the housing 1. It is worth noting that "reducing the diameter of the shaft end of the housing unit Q with the weld mark 3" means that after the housing 1 and the end cover 2 are side-welded together, at least the weld mark 3 is reduced in diameter. However, considering the differences in welding process and structural shape, as well as the different reduction methods, it is possible that not only the weld mark 3 is reduced in diameter, but other structures near the weld mark 3, such as the end of the housing 1 or the edge of the end cover 2, may also be reduced in diameter.

[0274] For example, when one axial end of the housing 1 is open to form an open end 1a and the other axial end is closed to form a closed end 1b, after welding the end cap 2 to that end, the resulting housing unit Q includes the housing 1, an end cap 2 and a weld mark 3. At this time, the housing unit Q can serve as a complete housing component 1021. Therefore, before welding the housing 1 and the end cap 2, the electrode component 1022 can be installed into the housing 1 first, and then the housing 1 and the end cap 2 can be welded. After that, the weld mark 3 area is narrowed.

[0275] For example, when both ends of the housing 1 are open ends 1a, an end cap 2 can be welded to one end first. The resulting housing unit Q (denoted as the first housing unit) consists only of the housing 1, one end cap 2, and one weld mark 3. Then, after welding the end cap 2 to the other end, the resulting housing unit Q (denoted as the second housing unit) consists of the housing 1, two end caps 2, and two weld marks 3. In this scheme, the weld mark 3 area obtained first in the first housing unit can be narrowed first, and then the welded second housing unit can be obtained, followed by narrowing the weld mark 3 area obtained later in the second housing unit. Alternatively, after obtaining the second housing unit, the weld mark 3 areas at both ends can be narrowed sequentially or simultaneously. It is understood that when the two end caps 2 are welded to the housing 1 sequentially, the electrode component 1022 needs to be installed into the housing 1 before welding the latter end cap 2.

[0276] The specific method of "reduction treatment" in "reduction treatment of the shaft end with solder mark 3 of housing unit Q" is not limited. For example, it can be physical extrusion, grinding, heat treatment, etc., as long as the solder mark 3 is reduced radially inward along the housing 1 within the cylindrical surface S of the outer circumferential surface 1c of the housing 1. It should be noted that the reduction treatment should ensure that the strength and sealing performance of the solder mark 3 are not affected, and ensure the reliability of the cylindrical battery 102.

[0277] Referring to the description of the above embodiment, "the solder mark 3 is recessed inward along the radial direction of the housing 1 within the cylindrical surface S where the outer peripheral surface 1c of the housing 1 is located" means that in any radial direction of the housing 1, the solder mark 3 will not protrude beyond the cylindrical surface S where the outer peripheral surface 1c of the housing 1 is located along that radial direction, thereby solving the problem of the outer diameter being too large at the solder mark 3, so that the reliability and energy density of the cylindrical battery 102 after assembly can be better balanced.

[0278] In summary, by reducing the diameter of the shaft end with the solder mark 3 of the housing unit Q, the solder mark 3 is radially recessed within the cylindrical surface S of the outer circumferential surface 1c of the housing 1. This solves the problem of the large outer diameter at the solder mark 3, allowing for a better balance between the reliability and energy density of the cylindrical battery 102 after assembly. Furthermore, the reduction treatment targets the solder mark 3 formed after the housing 1 and the end cap 2 are welded together, meaning that the solder mark 3 that causes the large outer diameter is directly treated. This ensures more directly and effectively that the solder mark 3 is radially recessed within the cylindrical surface S of the outer circumferential surface 1c of the housing 1. Additionally, since the housing 1 and the end cap 2 are side-welded, the welding operation is convenient, and the connection strength and sealing of the weld are good, which helps to improve the overall reliability of the cylindrical battery 102.

[0279] Referring to Figures 12 and 13, Figure 13 is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application. In some embodiments, "step S400: performing a necking process on the shaft end of the housing unit Q with the solder mark 3" specifically includes: step S410: pressing the shaft end of the housing unit Q with the solder mark 3 to perform a necking process, so that the solder mark 3 is radially recessed into the cylindrical surface S where the outer peripheral surface 1c of the housing 1 is located. Thus, the necking is achieved by directly pressing the solder mark 3, and the solder mark 3 is only a physical change in shape. There is no loss of material in the solder mark 3, and the material of the solder mark 3 does not change, thereby better ensuring the connection strength and sealing performance between the housing 1 and the end cap 2.

[0280] Referring to Figures 13 and 14, Figure 14 is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application. In some embodiments, "step S410: pressing the shaft end of the housing unit Q with the solder mark 3 to perform a necking process" specifically includes: step S411: simultaneously applying a necking extrusion force to the shaft end (i.e., the shaft end of the housing unit Q with the solder mark 3) at multiple positions spaced apart along the circumference of the housing 1, and causing the multiple positions where the extrusion force is applied to move synchronously and in the same direction along the circumference of the housing 1.

[0281] "Simultaneously applying the necking extrusion force" means applying the extrusion force synchronously in time, not sequentially or one by one. "Synchronously transferring in the same direction along the circumference of the shell 1" means transferring at the same speed and direction, such as synchronously transferring clockwise along the circumference of the shell 1, or synchronously transferring counterclockwise along the axial direction of the shell 1. This improves the uniformity of force on the circumferential end of the shell unit Q with the weld mark 3 during the necking process, avoiding deformation or damage caused by time differences. It helps reduce the circumferential torsional deformation of the weld mark 3 during the necking process, thereby improving the stability and reliability of the weld mark 3 connecting the shell 1 and the end cap 2. This method improves the coordination and consistency of the necking process, avoiding shape distortion or dimensional deviations caused by asynchronous or non-directional movements.

[0282] The method of "synchronously and in the same direction transferring multiple positions applying extrusion pressure along the circumference of housing 1" is not limited. For example, in some embodiments, synchronous and in the same direction transfer can be achieved by controlling the movement trajectory and speed of the necking tool (e.g., the force-applying head) used to extrude the shaft end. For example, when the shaft end with the weld mark 3 of housing unit Q is extruded by the force-applying head, multiple force-applying heads can be set and spaced apart along the circumference of housing 1. The multiple force-applying heads are driven to simultaneously extrude the shaft end with the weld mark 3 of housing unit Q and move synchronously and in the same direction (e.g., all in a clockwise direction along the circumference of housing 1 or a counterclockwise direction along the circumference of housing 1), thereby gradually completing the full circumferential necking of the shaft end with the weld mark 3 of housing unit Q. For example, in other embodiments, the necking tool (e.g., the force-applying head) used to extrude the shaft end can also remain stationary, and the rotation of housing unit Q can be controlled to achieve "synchronous and in the same direction transferring multiple positions applying extrusion pressure along the circumference of housing 1".

[0283] For example, a narrowing extrusion force can be simultaneously applied to two, three, four, five, six, or an infinite number of positions on the shaft end of the housing unit Q with the solder mark 3, which are spaced apart along the circumference of the housing 1. The positions where the narrowing extrusion force is applied can be evenly distributed along the circumference of the shaft end.

[0284] Therefore, by simultaneously applying necking pressure at multiple circumferentially spaced positions along the housing 1 to the shaft end, and ensuring that these multiple pressure application points move synchronously and in the same direction along the circumference of the housing 1, the uniformity of force on the shaft end of the housing unit Q in the circumferential direction during the necking process is improved. This reduces the possibility of shaft end deformation or damage due to uneven local force, thereby helping to maintain the structural reliability and sealing of the solder mark 3, and reducing problems such as electrolyte leakage caused by improper necking during the use of the cylindrical battery 102. Furthermore, since the necking process is performed simultaneously at multiple positions, the processing cycle can be shortened, and production costs reduced.

[0285] Referring to Figures 13, 15-18, Figure 15 is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application, Figure 16 is a schematic diagram of a compression opening using a force-applying head in some embodiments of this application, Figure 17 is a schematic diagram of a compression opening using a force-applying head in some other embodiments of this application, and Figure 18 is a schematic diagram of a compression opening using a force-applying head in some still other embodiments of this application.

[0286] In some embodiments, "step S410: pressing the shaft end of the housing unit Q with the solder mark 3 for narrowing treatment" specifically includes: step S421: providing a force-applying head 71 with a force-applying surface 711; step S422: positioning the force-applying head 71 with the force-applying surface 711 facing the shaft end, and tilting the force-applying surface 711 in a direction gradually away from the central axis L of the housing 1 along the direction from the end cap 2 to the housing 1; step S423: pushing the force-applying head 71 along the axial direction of the housing 1, for example, the first direction F1 shown in the figure, so that the shaft end of the housing unit Q with the solder mark 3 is pressed by the force-applying surface 711.

[0287] During this process, the force-applying surface 711 will closely contact and squeeze the shaft end with the weld mark 3 of the housing unit Q. The force-applying surface 711 is inclined in the direction away from the central axis L of the housing 1 along the direction from the end cover 2 to the housing 1. As the force-applying head 71 is fed along the axial direction of the housing 1 (e.g., the first direction F1 shown in the figure), the force-applying surface 711 will guide the shaft end material to undergo a narrowing deformation in the direction away from the central axis L of the housing 1, thereby achieving the effect of diameter reduction.

[0288] The shape of the force-applying head 71 is not limited; for example, it can be conical (e.g., refer to Figure 16), cylindrical (e.g., refer to Figure 17), wedge-shaped (e.g., refer to Figure 18), etc. By setting the placement posture, the force-applying surface 711 can be in the aforementioned inclined shape. As the force-applying head 71 feeds along the axial direction of the housing 1 (e.g., the first direction F1 shown in the figure), the force-applying surface 711 gradually and continuously presses the shaft end, thereby helping to maintain the smoothness and continuity of the necking process and ensuring the structural strength of the weld mark 3 after necking.

[0289] In the above technical solution, by driving the force-applying head 71 with the aforementioned inclined force-applying surface 711 to feed along the axial direction of the housing unit Q, the necking extrusion pressure can be applied evenly, continuously, and smoothly to the weld stamp 3. The weld stamp 3 undergoes uniform and continuous plastic deformation under the extrusion pressure, thereby reducing the possibility of damage to the weld stamp 3 due to unstable extrusion pressure, ensuring the structural strength of the weld stamp 3 after necking, and ensuring the reliability of the connection between the housing 1 and the end cap 2. Furthermore, by controlling the inclination angle of the force-applying surface 711, the degree and shape of the necking can be precisely controlled, and by adjusting the inclination angle of the force-applying surface 711, different necking effects can be achieved for products of different sizes, thereby meeting different processing requirements and improving processing flexibility.

[0290] Referring to Figure 19, which is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application, in some embodiments, before the step "step S400: performing a necking process on the shaft end of the housing unit Q with the solder mark 3", the method further includes step S500: a clamping process to ensure that the housing unit Q can be stably necked. The clamping process can be performed after the housing 1 and end cap 2 are welded together to form the housing unit Q, or, in other embodiments, it can be performed before the housing 1 and end cap 2 are welded together.

[0291] For example, step S500: clamping process, may specifically include the following two steps.

[0292] Step S510: Apply radial clamping forces at multiple circumferentially spaced positions on the outer periphery of the housing unit Q, with the radial clamping forces pointing radially inwards towards the interior of the housing 1. That is, apply radial clamping forces to the outer periphery of the housing unit Q, with these forces pointing radially inwards towards the interior of the housing 1. Multiple radial clamping forces are applied and distributed circumferentially around the housing 1. Thus, during the subsequent necking process, the radial clamping forces securely clamp the outer periphery of the housing unit Q, preventing rotation or radial displacement during the necking process. This effectively fixes the housing unit Q. Furthermore, because the radial clamping forces are distributed circumferentially, it prevents the housing unit Q from shaking or rotating due to uneven force during the necking process, limiting radial displacement and maintaining its correct circumferential position, thereby contributing to the stability and effectiveness of the necking process.

[0293] Step S520: Apply an axial support force to the end of the housing unit Q that is axially away from the end cap 2. The axial support force is directed axially towards the end cap 2. That is, apply an axial support force to the axial end of the housing unit Q, and the axial support force is along the direction from the housing 1 to the end cap 2 in the axial direction of the housing 1. Thus, by applying an axial support force to the end of the housing unit Q that is axially away from the end cap 2, the axial displacement of the cylindrical battery 102 can be restricted, keeping it in the correct axial position, which is beneficial to the stability and effectiveness of the subsequent necking process. In addition, since the end of the housing unit Q that is axially close to the end cap 2 needs to be necked, when the driving force head 71 is used to feed and compress the neck along the axial direction, this end does not need to be axially supported, thereby avoiding the problem of over-limiting.

[0294] Therefore, by applying radial clamping forces at multiple circumferentially spaced positions on the outer periphery of the housing unit Q, the outer periphery of the housing unit Q is securely clamped during the necking process to prevent rotation or radial displacement of the housing unit Q during the necking process. Furthermore, by applying axial support forces to the end of the housing unit Q away from the end cap 2 in the axial direction, stable axial support is provided for the housing unit Q during the necking process to prevent axial displacement of the housing unit Q due to the necking extrusion force, thereby ensuring that the necking process can be carried out smoothly and reliably.

[0295] It should be noted that the order of steps S510 and S520 is not limited. For example, step S510 can be performed after step S520, that is, first applying an axial support force to one end of the housing unit Q away from the end cover 2 in the axial direction, and then applying a radial clamping force to multiple circumferentially spaced positions on the outer periphery of the housing unit Q. Alternatively, step S510 can be performed before step S520, that is, first applying a radial clamping force to multiple circumferentially spaced positions on the outer periphery of the housing unit Q, and then applying an axial support force to one end of the housing unit Q away from the end cover 2 in the axial direction. Furthermore, steps S510 and S520 can be performed simultaneously.

[0296] Referring to FIG20, FIG20 is a schematic block diagram of a method for processing a cylindrical battery according to some embodiments of the present application. In some embodiments, after the step "step S400: performing a necking process on the shaft end of the housing unit Q with the solder mark 3", the method further includes: step S600: covering the housing unit Q with a protective layer 4, such that the protective layer 4 at least covers the solder mark 3. For example, referring to the embodiments shown in FIG9 and FIG10, the protective layer 4 is configured to include at least a first covering portion 41, which covers the periphery of the solder mark 3.

[0297] The phrase "ensuring that the protective layer 4 at least covers the solder mark 3" means that the protective layer 4 must at least cover the solder mark 3 to ensure that the solder mark 3 is protected. For example, the protective layer 4 may only cover the solder mark 3. Alternatively, while covering the solder mark 3, the protective layer 4 may also extend as needed to cover other parts of the housing unit Q, such as a part of the outer peripheral surface 1a of the housing 1, and / or a part of the end cap 2 near the edge, to reduce the processing difficulty of the protective layer 4 and provide more comprehensive protection.

[0298] Therefore, by covering the outer casing unit Q with a protective layer 4, which at least covers the solder mark 3, the solder mark 3 can be effectively protected, thereby extending the connection reliability and sealing performance of the solder mark 3, and thus improving the reliability of the cylindrical battery 102.

[0299] It is worth noting that the material of the protective layer 4 is not limited. For example, it can be rust-proof material, insulating material, anti-corrosion material, heat-insulating material, wear-resistant material, impact-resistant material, etc., to achieve at least one of the functions of rust prevention, insulation, heat insulation, anti-corrosion, wear resistance, and impact resistance. In addition, the covering method of the protective layer 4 is not limited.

[0300] It is worth noting that the coating method of the protective layer 4 is not limited. For example, it can be UV printing, injection molding, coating (such as spraying or dipping), heat sealing, plating, etc. For example, the protective layer 4 can be a rust-proof layer, and can be at least one of a UV adhesive printing layer, an ink coating layer, and a metal plating layer. Thus, the protective layer 4 can be flexibly selected, is easy to process, and can achieve a good rust-proof effect.

[0301] In some embodiments, "step S600: covering the housing unit Q with a protective layer 4" specifically involves covering the housing unit Q with a protective layer 4 using UV adhesive printing. Thus, the protective layer 4 can be a UV adhesive printed layer, providing rust protection and extending the connection reliability and sealing of the solder joint 3, thereby improving the reliability of the cylindrical battery 102. Furthermore, the UV adhesive printed layer has a long service life and is easy to process.

[0302] For example, when applying the protective layer 4 to the housing unit Q using UV adhesive printing, the housing unit Q can be placed on the printing platform and fixed in position. Then, the UV adhesive printer can be started, and the UV adhesive can be evenly sprayed onto the surface of the housing unit Q, especially the solder area 3, according to the preset printing path. During the spraying process, the UV adhesive can be rapidly cured and form the protective layer 4 by precisely controlling the irradiation time and intensity of the UV light source.

[0303] Therefore, by printing a protective layer 4 onto the housing unit Q using UV adhesive, the protective layer 4 can be uniformly and precisely covered on the housing unit Q. Especially for critical areas such as the solder joints 3, the amount of adhesive applied to the solder joints 3 can be increased, resulting in a denser protective layer 4 and increasing its thickness. The protective layer 4 formed after UV adhesive curing typically exhibits good weather resistance, corrosion resistance, and abrasion resistance, effectively resisting environmental erosion and providing focused protection for the solder joints 3. Furthermore, UV adhesive cures rapidly under ultraviolet light, shortening the production cycle and improving production efficiency.

[0304] In some embodiments, a protective layer 4 is applied to the outer surface of the housing unit Q, such that the protective layer 4 covers the solder mark 3 and also covers at least the edge position of the shaft end on the axial side away from the housing 1. For example, referring to the embodiment shown in FIG9, the protective layer 4 is configured to include a first covering portion 41 and a second covering portion 42. The first covering portion 41 covers the periphery of the solder mark 3, and the second covering portion 42 covers at least the edge position of the shaft end of the housing unit Q where the solder mark 3 is located on the axial side away from the housing 1. That is, the second covering portion 42 is connected to the first covering portion 41 and is located on the axial side of the housing 1 away from the housing 1 of the first covering portion 41, and covers the end cap 2 and / or the solder mark 3.

[0305] This allows the protective layer 4 to have a larger coverage area, thereby reducing the positional accuracy required when setting the protective layer 4. While ensuring effective protection of the solder mark 3, it also reduces the processing difficulty of the protective layer 4 and improves processing efficiency. Furthermore, by extending the protective layer 4 to the edge of the shaft end away from the housing 1, these vulnerable areas can be effectively protected. These edge areas are easily subjected to external forces such as friction and impact during the use and installation of the cylindrical battery 102; therefore, the additional protective layer 4 provides protection, extends the service life of the cylindrical battery 102, and thus improves the reliability of the cylindrical battery 102.

[0306] In some embodiments, a protective layer 4 is applied to the outer surface of the housing unit Q, such that the protective layer 4 covers the solder stamp 3 and also covers the outer peripheral surface 1c of the housing 1. For example, referring to the embodiment shown in FIG10, the protective layer 4 is configured to include a first covering portion 41 and a third covering portion 43. The first covering portion 41 covers the periphery of the solder stamp 3, and the third covering portion 43 covers the outer peripheral surface 1c of the housing 1. The third covering portion 43 is connected to the first covering portion 41 and is located on the side of the first covering portion 41 away from the end cap along the axial direction of the housing 1.

[0307] This allows the protective layer 4 to have a larger coverage area, thereby reducing the positional accuracy required when setting the protective layer 4. While ensuring effective protection of the solder mark 3, it also reduces the processing difficulty of the protective layer 4 and improves processing efficiency. Furthermore, by extending the protective layer 4 to the outer peripheral surface 1c of the casing 1, the overall protective capability of the cylindrical battery 102 can be enhanced. As the main structural component of the cylindrical battery 102, the outer peripheral surface 1c of the casing 1 is susceptible to various external factors during the use, transportation, and storage of the cylindrical battery 102, such as scratches, impacts, and corrosion. The coverage of the protective layer 4 can effectively reduce these damages, extend the service life of the cylindrical battery 102, and thus improve the reliability and safety of the cylindrical battery 102.

[0308] The protective layer 4 covers the outer peripheral surface 1c of the shell 1. It can be used to completely cover the entire outer peripheral surface 1c of the shell 1 within the protective layer 4, or it can be used to partially cover the part of the outer peripheral surface 1c of the shell 1 that is close to the solder mark 3, thereby improving the overall protection capability of the solder mark 3.

[0309] For example, a protective layer 4 is wrapped around the housing unit Q, so that the protective layer 4 covers the solder mark 3 and also covers at least the edge position of the shaft end away from the housing 1 in the axial direction, and also covers the outer peripheral surface 1c of the housing 1. Thus, the protective layer 4 may also include the first covering part 41, the second covering part 42 and the third covering part 43 at the same time, so as to have more comprehensive protective performance.

[0310] Referring to Figure 21, which is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application, in some embodiments, after the step "step S600: covering the outer surface of the housing unit Q with a protective layer 4", the method further includes: step S700: covering the outer peripheral surface 1c of the housing 1 with a protective film 5, wherein the protective film 5 is a pre-formed film and the area covered by the protective film 5 is a coating area, and the area covered by the protective layer 4 is a coating area, and the coating area is located at one end of the coating area along the axial direction of the housing, for example, referring to Figure 11.

[0311] As described in the previous embodiments, the protective film 5 is a pre-formed film, meaning that the protective film 5 has been processed into a thin film form before being wrapped around the housing 1, and then the film is wrapped onto the outer peripheral surface 1c of the housing 1 through an assembly process. The material of the protective film 5 is not limited, and for example, the material of the protective film 5 can be selected according to at least one of the requirements of rust prevention, insulation, heat insulation, corrosion prevention, wear resistance, and impact resistance.

[0312] Therefore, by covering the housing unit Q with a protective film 5 and a protective layer 4, multiple protections for the housing unit Q are achieved, improving the reliability of the cylindrical battery 102. Moreover, by using a protective film 5 to cover the outer peripheral surface 1c of the housing 1, it is not necessary to cover the outer peripheral surface 1c of the housing 1 with the protective layer 4 while simultaneously covering the solder mark 3 (i.e., it can replace the third covering part 43), thereby saving material for the protective layer 4 and improving the processing efficiency of the protective layer.

[0313] It is worth noting that the extent to which the protective film 5 covers the housing 1 is not limited. For example, the dimension of the protective film 5 along the axial direction of the housing 1 is consistent with the axial length of the housing 1, so as to completely cover the outer peripheral surface 1c of the housing 1. Alternatively, the dimension of the protective film 5 along the axial direction of the housing 1 can also be smaller than the axial length of the housing 1, thereby covering only a portion of the outer peripheral surface 1c of the housing 1. In addition, at the junction of the protective film 5 and the protective layer 4, the protective film 5 can be wrapped with the protective layer 4, thereby further improving the reliability of the cylindrical battery 102.

[0314] Referring to Figure 22, which is a schematic block diagram of a cylindrical battery processing method provided in some embodiments of this application, and in conjunction with Figures 5 and 6, in some embodiments, the end cap 2 includes an edge portion 21 and a central portion 22. The step "step S200: covering the opening end 1a with the end cap 2" specifically includes: step S210: overlapping the edge portion 21 with the axial side of the opening end 1a of the housing 1; step S220: extending the central portion 22 into the opening end 1a and interfering with the opening end 1a.

[0315] Therefore, since the central part 22 extends into the opening end 1a and is interference-fitted with the opening end 1a, the pre-assembly of the shell 1 and the end cap 2 is reliable, which is conducive to subsequent stable welding. In the subsequent side welding process, the two can be effectively welded together, resulting in a high yield rate after welding. Defects such as cracks and shrinkage cavities are not likely to appear in the weld mark 3, thereby improving the reliability of the connection between the end cap 2 and the shell 1 and forming a tighter seal. When gas or pressure changes occur inside the battery due to charging and discharging, this tight seal can more effectively prevent gas leakage or electrolyte leakage, and maintain the stability of the internal environment of the cylindrical battery 102.

[0316] Referring to Figure 23, which is a structural schematic diagram of a necking device provided in some embodiments of this application, this application also provides a necking device 200.

[0317] The necking device 200 is used to neck the shaft end of a cylindrical workpiece 300. The term "cylindrical workpiece 300" is not specifically limited. For example, when necking is required on the weld mark 3 area after welding the housing 1 and end cap 2, the necking device 200 can be used. In this case, the housing unit Q serves as the cylindrical workpiece 300 to be necked, and the shaft end of the housing unit Q with the weld mark 3 serves as the shaft end of the cylindrical workpiece 300 to be necked. As another example, when necking is required on the open end 1a of the housing 1 before welding the housing 1 and end cap 2, the necking device 200 can also be used. In this case, the housing 1 serves as the cylindrical workpiece 300 to be necked, and the open end 1a of the housing 1 serves as the shaft end of the cylindrical workpiece 300 to be necked. Narrowing the shaft end of the workpiece 300 means reducing the diameter of the shaft end, i.e., decreasing its outer diameter.

[0318] Referring to Figures 23-25, Figure 24 is an enlarged view of point B of the necking device shown in Figure 23; Figure 25 is a schematic diagram of a necking device provided in some embodiments of this application. The necking device 200 includes a clamping device 6, a necking device 7, a feed drive device 8, and a rotary drive device 9. The clamping device 6 is used to clamp a workpiece 300. The space occupied by the workpiece 300 clamped by the clamping device 6 is a workpiece space 65. The axial sides of the workpiece space 65 are a first side 651 and a second side 652, respectively. The central axis L2 of the workpiece space 65 is a reference line L5. The necking device 7 includes a force-applying head 71, which is located on the first side 651 and includes a force-applying surface 711 for necking the axial end of the workpiece 300. The distance J between the force-applying surface 711 and the reference line L5 gradually increases along the direction from the first side 651 to the second side 652 (i.e., along the direction from the first side 651 to the second side 652 in the extension direction of the reference line L5, the distance J between the force-applying surface 711 and the reference line L5 gradually increases). The feed drive device 8 drives at least one of the force-applying head 71 and the clamping device 6 to perform a feed movement along the extension direction of the reference line L5, so that the force-applying surface 711 presses the shaft end of the workpiece 300 to achieve narrowing. The rotary drive device 9 drives at least one of the force-applying head 71 and the clamping device 6 to rotate around the reference line L5.

[0319] The feed drive device 8 can act on any object, for example, it can act on the clamping device 6 (directly or indirectly connected to the clamping device 6) to drive the workpiece 300 held by the clamping device 6, causing relative movement between the workpiece 300 and the force application surface 711, thus achieving extrusion and compression. Alternatively, it can act on the force application head 71 (directly or indirectly connected to the force application head 71) to drive the force application surface 711 of the force application head 71, causing relative movement between the force application surface 711 and the workpiece 300, thus achieving extrusion and compression. Furthermore, it can act simultaneously on the force application head 71 (directly or indirectly connected to the force application head 71) and the clamping device 6 (directly or indirectly connected to the clamping device 6), driving the force application head 71 and the clamping device 6 respectively, causing relative movement between the force application surface 711 and the workpiece 300, thus achieving extrusion and compression.

[0320] Furthermore, the driving direction and specific configuration of the feed drive device 8 are not limited. The driving direction can be to feed only along the axial direction of the cylindrical workpiece 300, or it can feed along the axial and radial directions of the cylindrical workpiece 300 respectively. The specific configuration can be selected according to the driving direction. For example, it can include a motor and a transmission mechanism. By precisely controlling its movement speed and direction, precise control of the necking process can be achieved.

[0321] The rotary drive device 9 has no limited target. For example, it can act on the clamping device 6 (directly or indirectly connected to the clamping device 6) to drive the workpiece 300 held by the clamping device 6, causing the workpiece 300 to rotate relative to the force-applying surface 711. Alternatively, it can act on the force-applying head 71 (directly or indirectly connected to the force-applying head 71) to drive the force-applying surface 711 of the force-applying head 71, causing the force-applying surface 711 to rotate relative to the workpiece 300. Furthermore, it can act simultaneously on the force-applying head 71 (directly or indirectly connected to the force-applying head 71) and the clamping device 6 (directly or indirectly connected to the clamping device 6), driving the force-applying head 71 and the clamping device 6 respectively, causing the force-applying surface 711 to rotate relative to the workpiece 300.

[0322] In the above technical solution, when the workpiece 300 is clamped by the clamping device 6, the feed drive device 8 and the rotary drive device 9 can perform driving operations respectively, so that the shaft end of the workpiece 300 can be gradually squeezed by the force application surface 711. Under the squeezing action of the force application surface 711, the shaft end of the workpiece 300 can gradually shrink in diameter along the extension direction of the reference line L5. That is, the outer diameter of the shaft end of the workpiece 300 gradually shrinks along the extension direction of the reference line L5, or in other words, the radial shrinkage degree of the shaft end of the workpiece 300 gradually increases from the second side 652 to the first side 651, without a sudden step-like shrinkage. This makes the structural strength of the shrinkage part of the workpiece 300 reliable, and the shrinkage degree of the workpiece 300 is uniform throughout the entire circumference, which is conducive to further improving the shrinkage quality. Furthermore, by setting a rotary drive device 9 to drive at least one of the force-applying head 71 and the clamping device 6 to rotate around the reference line L5, axial feeding can be performed while rotating, so that the extrusion force can be gradually applied to the shaft end of the workpiece 300, and the amount of retraction applied to the shaft end of the workpiece 300 is also gradually increased. This avoids damage to the workpiece 300 caused by a large amount of retraction acting directly on the shaft end of the workpiece 300. It can also avoid the problem that the end of the workpiece 300 is too hard (for example, the wall thickness of the opening end 1a of the housing 1 is large, or the end cap 2 has been welded to the housing 1) and cannot be effectively narrowed, thereby improving the applicability of the narrowing process.

[0323] For example, when the area of ​​the weld mark 3 is reduced after the shell 1 and the end cap 2 are welded using the aforementioned reducing device 200, the weld mark 3 can be reduced radially inward within the cylindrical surface S of the outer circumferential surface 1c of the shell 1. The radial reduction dimension T of the weld mark 3 relative to the cylindrical surface S of the shell 1 gradually increases in the axial direction of the shell 1 from the shell 1 to the end cap 2. This ensures that the weld mark 3 at the connection between the shell 1 and the end cap 2 does not have an outward protrusion problem, solves the problem of the outer diameter being too large at the weld mark 3, and allows the reliability and energy density of the cylindrical battery 102 after assembly to be better balanced.

[0324] It is worth noting that the timing and speed of the feed drive device 8 driving at least one of the clamping device 6 and the force-applying head 71 to feed along the extension direction of the reference line L5, and the rotation drive device 9 driving at least one of the force-applying head 71 and the clamping device 6 to rotate around the reference line L5, can all be set by the control program. After reading the technical solution of this application, those skilled in the art can flexibly design it according to the actual needs of the narrowing.

[0325] Referring to Figures 26 and 27, Figure 26 is a partial structural schematic diagram of the necking device provided in some embodiments of this application; Figure 27 is an enlarged view of point C of the necking device shown in Figure 26. In some embodiments, the rotary drive device 9 includes: a rotating base 91 and a rotary drive mechanism 92, a force-applying head 71 is disposed on the rotating base 91 (for example, the force-applying head 71 can be directly or indirectly installed on the rotating base 91) to rotate synchronously with the rotating base 91 around the reference line L5, and the rotary drive mechanism 92 is connected to the rotating base 91 (directly or indirectly) to drive the rotating base 91 to rotate around the reference line L5.

[0326] In the above technical solution, the rotary drive device 9 can drive the force application head 71 to rotate around the reference line L5 through the rotating seat 91 and the rotary drive mechanism 92. During the process of the workpiece 300 being narrowed, the workpiece 300 does not need to rotate around the reference line L5, thereby simplifying the clamping device 6.

[0327] Please refer again to Figures 26 and 27. In some embodiments, there are multiple force-applying heads 71, which are spaced apart along the direction surrounding the reference line L5. When the rotating seat 91 rotates, it drives the multiple force-applying heads 71 ​​to rotate synchronously and in the same direction around the reference line L5.

[0328] In the above technical solution, during the necking process, multiple force-applying heads 71 ​​can rotate synchronously with the rotating seat 91. At this time, the multiple force-applying heads 71 ​​can achieve synchronous and unidirectional transfer along the circumference of the workpiece 300 to synchronously squeeze the shaft end of the workpiece 300. This can improve the uniformity of force on the workpiece 300 during the necking process, help reduce the circumferential torsional deformation of the workpiece 300 during the necking process, thereby improving the necking quality of the workpiece 300. Moreover, since multiple circumferential points are squeezed and necked simultaneously, the necking efficiency can be improved. In addition, by setting multiple force-applying heads 71, the shaft end of the workpiece 300 being necked can also be radially limited. At the same time, since the force-applying surface 711 is inclined to the reference line L5, the multiple force-applying heads 71 ​​can also axially limit the shaft end of the workpiece 300 being necked. This eliminates the need to set up a mechanism for applying radial and axial clamping forces at this end (the shaft end of the workpiece 300 being necked), thereby simplifying the necking equipment 200.

[0329] The form of the force-applying head 71 in the phrase "multiple force-applying heads 71 ​​are spaced apart along the direction surrounding the reference line L5, and when the rotating seat 91 rotates, it drives multiple self-rotating rollers 71a to rotate synchronously and in the same direction around the reference line L5" is not limited. For example, it may include, but is not limited to, the self-rotating rollers 71a or wedge blocks 71b described below, which will be described separately below.

[0330] In some embodiments, the necking device 7 includes: a roller base 72, and a force-applying head 71, which is a rotating roller 71a and is rotatably mounted on the roller base 72, wherein the outer peripheral surface of the rotating roller 71a constitutes a force-applying surface 711. For example, the roller base 72 and the rotating roller 71a can be connected by a bearing, thereby enabling the rotating roller 71a to rotate freely.

[0331] In the above technical solution, the force-applying head 71 is a self-rotating roller 71a. During the necking process, the self-rotating roller 71a can rotate around its own axis (i.e., it rotates), so that the friction between the self-rotating roller 71a and the workpiece 300 is rolling friction rather than sliding friction. This helps to reduce the friction force generated during the necking process, thereby reducing the wear between the self-rotating roller 71a and the workpiece 300, extending the service life of the self-rotating roller 71a, improving the structural reliability of the necking part of the workpiece 300, and reducing the cutting of the workpiece 300 by the force-applying head 71, reducing the generation of chips, reducing problems such as product short circuits caused by chip generation, and improving product reliability. Furthermore, since a rotary drive device 9 is provided and the force-applying head 71 is a self-rotating roller 71a, there are two relative motions between the self-rotating roller 71a and the workpiece 300: revolution and rotation. In this way, the inclined force-applying surface 711 is driven by revolution and rotation to squeeze the part to be narrowed, and the narrowing is performed effectively regardless of the hardness of the part of the workpiece 300 to be narrowed (for example, the wall thickness of the opening end 1a of the shell 1 is large, or the end cap 2 has been welded to the shell 1).

[0332] For example, when the weld mark 3 formed by the side welding of the casing 1 and end cap 2 of the cylindrical battery 102 has excess height and needs to be reduced, the reduction device 200 of this application embodiment can be used. The force application surface 711 formed by the outer peripheral surface of the rotating roller 71a feeds along the axial direction of the cylindrical battery 102 and rotates circumferentially to squeeze the weld mark 3 area. After reduction, the weld mark 3 can be radially reduced within the cylindrical surface S of the outer peripheral surface 1c of the casing 1, resulting in high consistency of the outer diameter of the cylindrical battery 102 (0.1 can achieve a 3σ level), eliminating the safety hazard of creepage distance. In statistics, a 3σ level means that the probability of the product quality characteristic value falling within the mean ± 3 times the standard deviation is 99.73%. If the tolerance range of the outer diameter of the cylindrical battery 102 is set to 0.1, and a 3σ level is to be achieved, then the standard deviation of the outer diameter of the cylindrical battery 102 needs to be controlled within 0.1 ÷ 6 ≈ 0.0167.

[0333] Please refer again to Figures 26 and 27. There are multiple rotating rollers 71a, which are spaced apart along the direction surrounding the reference line L5. When the rotating seat 91 rotates, it drives the multiple rotating rollers 71a to rotate synchronously and in the same direction around the reference line L5. Thus, the multiple rotating rollers 71a on the rotating seat 91 can surround the end of the workpiece 300 to be narrowed at intervals along the circumference of the workpiece 300.

[0334] In the above technical solution, during the necking process, multiple rotating rollers 71a can not only revolve synchronously with the rotating seat 91, but each rotating roller 71a can also rotate on its own axis. At this time, multiple rotating rollers 71a can realize synchronous and unidirectional transfer and extrusion along the circumference of the workpiece 300, thereby improving the uniformity of force on the workpiece 300 during the necking process, helping to reduce the circumferential torsional deformation of the workpiece 300 during the necking process, thereby improving the necking quality of the workpiece 300. Moreover, since multiple circumferential points are squeezed and necked at the same time, the necking efficiency can be improved.

[0335] In the embodiments of this application, when there are multiple self-rotating rollers 71a, the number is not limited, for example, it can be 2, 3, 4, etc., so as to take into account both the simplification of the structure and the stable coordination of synchronous movement.

[0336] In some embodiments, when "there are multiple rotating rollers 71a and they are spaced apart along the direction surrounding the reference line L5", all rotating rollers 71a provided on the rotating seat 91 can be configured to have the same structure and the same installation method. Therefore, by using rotating rollers 71a with the same structure and installation method, each rotating roller 71a has the same performance during the necking process, thereby reducing the possibility of uneven radial necking of the workpiece 300 due to performance differences of individual rotating rollers 71a, reducing necking defects, improving necking quality and consistency, and using the same installation method can further simplify the structure and improve assembly efficiency.

[0337] Referring to Figures 28 and 29, Figure 28 is a schematic diagram of a necking device provided in some embodiments of this application; Figure 29 is a structural schematic diagram of the rotating roller shown in Figure 28. In some embodiments, the rotating roller 71a is in the shape of a conical cylinder (it can be a pointed cone or a frustum cone). That is, the rotating roller 71a has a variable cross-section structure, and the cross-section of the rotating roller 71a gradually decreases along the direction from the first side 651 to the second side 652.

[0338] Here, "the self-rotating roller 71a is in the shape of a cone" only means that the self-rotating roller 71a is generally in the shape of a cone, but it does not require that the self-rotating roller 71a be a solid cone. Other structures, such as mounting holes, can be processed on the self-rotating roller 71a as needed. The structure of the self-rotating roller 71a is also not limited. It can be a single piece, a composite piece, or an assembly.

[0339] Therefore, since the axis L3 of the rotating roller 71a is parallel to the central axis L2 of the workpiece space 65, the distance J between the force application surface 711 and the reference line L5 can gradually increase along the direction from the first side 651 to the second side 652. Thus, when setting the rotating roller 71a, it is not necessary to adjust the angle between the axis L3 of the rotating roller 71a and the central axis L2 of the workpiece space 65 to control the tilt angle of the force application surface 711, thereby reducing the installation difficulty of the rotating roller 71a.

[0340] Referring to Figures 30 and 31, Figure 30 is a schematic diagram of a necking device provided in some embodiments of this application; Figure 31 is a structural schematic diagram of the rotating roller shown in Figure 30. In some embodiments, the rotating roller 71a is cylindrical. That is, the rotating roller 71a has a uniform cross-section structure, so that the axis L3 of the rotating roller 71a can be tilted relative to the central axis L2 of the workpiece space 65, so that the distance J between the force application surface 711 and the reference line L5 gradually increases along the direction from the first side 651 to the second side 652. Thus, the rotating roller 71a has a simple structure, is easy to process, has low production cost, and is foolproof in installation.

[0341] Here, "the self-rotating roller 71a is cylindrical" only means that the self-rotating roller 71a is generally cylindrical, but it does not require that the self-rotating roller 71a be a solid cylinder. Other structures, such as mounting holes, can be processed on the self-rotating roller 71a as needed. The structural composition of the self-rotating roller 71a is also not limited. It can be a single piece, a composite piece, or an assembly.

[0342] Referring again to Figure 27, in some embodiments, the rotating roller 71a is detachably mounted to the roller base 72. As a consumable component during the necking process, the rotating roller 71a frequently comes into contact with the workpiece 300 and is subjected to pressure and wear. By detachably mounting the rotating roller 71a to the roller base 72, it can be easily inspected, cleaned, repaired, or replaced, thereby extending the service life of the necking equipment 200 and reducing maintenance costs.

[0343] Furthermore, considering that different workpieces 300 may require rotating rollers 71a of different shapes, sizes, or materials for necking, designing the rotating roller 71a as detachable facilitates replacement and expands the applicability of the necking device 200. For example, when the rotating roller 71a is a conical cylinder, different taper angles of rotating rollers 71a can be used to obtain force application surfaces 711 with different inclination angles, thereby adapting to the necking requirements of different workpieces 300 and further expanding the applicability of the necking device 200.

[0344] In the embodiments of this application, "detachable installation" means that the connection between the rotating roller 71a and the roller base 72 allows the rotating roller 71a to be easily disassembled and reinstalled without damaging other parts of the equipment. Exemplarily, the connection method can be a bolt connection, a snap-fit ​​connection, a magnetic connection, etc.

[0345] Please refer again to Figures 25-27. In some embodiments, the narrowing device 7 includes a first adjustment mechanism 73, which is connected to the roller base 72 to adjust the tilt angle of the axis L3 of the rotating roller 71a relative to the reference line L5.

[0346] For example, whether the rotating roller 71a is in the shape of a cone or a cylinder, the tilt angle of the axis L3 of the rotating roller 71a relative to the reference line L5 can be adjusted by the first adjustment mechanism 73 to adapt to different necking requirements. That is, the axis L3 of the rotating roller 71a in the shape of a cone may not be parallel to the reference line L5, and the angle between the axis L3 of the rotating roller 71a in the shape of a cylinder and the reference line L5 can be flexibly adjusted.

[0347] In the above technical solution, by adjusting the angle of the roller base 72 through the first adjustment mechanism 73, the tilt angle of the force application surface 711 of the rotating roller 71a can be adjusted. Thus, according to the different shrinking requirements of the workpiece 300, the tilt angle of the axis L3 of the rotating roller 71a relative to the reference line L5 can be flexibly adjusted, so that the shrinking equipment 200 can perform shrinking processing on different workpieces 300, meet different shrinking requirements, and improve the applicability of the shrinking equipment 200.

[0348] Please refer again to Figures 26 and 27. In some embodiments, the first adjustment mechanism 73 includes an adjustment seat 731, a connecting shaft 732, and a locking member 733. The roller base 72 is rotatably mounted on the adjustment seat 731 via the connecting shaft 732. The locking member 733 is used to lock the relative angle between the roller base 72 and the adjustment seat 731. The axis L4 of the connecting shaft 732 intersects the reference line L5.

[0349] In the above technical solution, by unlocking the locking member 733, the relative angle between the roller base 72 and the adjusting seat 731 can be adjusted. This allows for adjustment of the tilt angle of the axis L3 of the rotating roller 71a according to different necking requirements, thereby expanding the applicability of the necking device 200. Locking the locking member 733 ensures that the adjusted relative angle between the roller base 72 and the adjusting seat 731 remains stable, reducing the possibility of angle changes due to vibration or external interference during operation, thus improving the working stability of the necking device 200. Furthermore, the first adjusting mechanism 73 of the above structural form has a simple structure, low cost, and is only a mechanical adjustment, making the adjustment operation simple and easily meeting adjustment requirements. Of course, this application is not limited to this. For example, in other embodiments of this application, the first adjusting mechanism 73 can also be configured to include a motor, etc., for electronic adjustment via electrical control.

[0350] Referring again to Figures 26 and 27, in some embodiments, the rotary drive device 9 includes a rotating base 91 and a rotary drive mechanism 92. A roller base 72 is disposed on the rotating base 91 to rotate synchronously with the rotating base 91 around the reference line L5. The rotary drive mechanism 92 is connected to the rotating base 91 to drive the rotating base 91 to rotate around the reference line L5. Thus, the rotary drive device 9 can drive the force-applying head 71 to rotate around the reference line L5 through the rotating base 91 and the rotary drive mechanism 92. During the necking process of the workpiece 300, it is not necessary for the workpiece 300 to rotate around the reference line L5, thereby simplifying the clamping device 6.

[0351] Referring to Figure 32, which is a schematic diagram of a necking device provided in some embodiments of this application, in some embodiments, the necking device 7 includes a second adjustment mechanism 74 connected between the rotating seat 91 and the roller base 72. The second adjustment mechanism 74 is used to adjust the position of the roller base 72 relative to the rotating seat 91 along a line perpendicular to the reference line L5, i.e., along the radial direction of the workpiece 300. This is equivalent to adjusting the position of the force-applying head 71 along the radial direction of the workpiece 300. Therefore, by providing the second adjustment mechanism 74, the radial position of the force-applying head 71 can be adjusted, thereby enabling necking processing of workpieces 300 with different outer diameters, thus increasing the applicability of the necking device 200.

[0352] The specific configuration of the second adjusting mechanism 74 is not limited. For example, the rotating seat 91 may have a groove extending radially along the workpiece 300, and the roller base 72 may include a connecting part that is radially slidably inserted through the groove and connected to the rotating seat 91. By adjusting the relative position of the connecting part and the groove, the radial position of the roller base 72 relative to the rotating seat 91 can be adjusted. Alternatively, the second adjusting mechanism 74 itself may include a radially driven mechanism, such as a gear and rack mechanism or a cylinder, thereby adjusting the radial position of the roller base 72 relative to the rotating seat 91 through electronic control.

[0353] Referring to Figure 33, which is a schematic diagram of a necking device provided in some embodiments of this application, in some embodiments, the force-applying head 71 is a wedge block 71b, and the inclined surface of the wedge block 71b constitutes the force-applying surface 711. It is worth noting that the wedge block 71b is a wedge-shaped structural member, and the wedge block includes two surfaces spaced apart along the thickness direction, one surface being a plane and the other surface being an inclined surface inclined to the plane, so that the thickness of the wedge block gradually decreases.

[0354] In the above technical solution, by setting a wedge block 71b, the wedge block 71b does not need to rotate relative to the rotating roller 71a, thereby simplifying the overall structure of the necking device 7 and reducing production costs. Moreover, all surfaces of the wedge block 71b except for the force application surface 711 can be constructed as flat surfaces, which facilitates fixation and improves the stability and reliability of the wedge block 71b during necking. Furthermore, since multiple wedge blocks 71b are spaced apart along the direction surrounding the reference line L5, when the rotating seat 91 rotates, it drives multiple force application heads 71 ​​to rotate synchronously and in the same direction around the reference line L5, which can also achieve radial and axial limiting of the workpiece 300 shaft end and improve the problem of torsional deformation of the workpiece 300.

[0355] In addition, an adjustment mechanism can be provided at the connection position between the wedge block 71b and the rotating seat 91, such as an angle adjustment mechanism 75 for adjusting the angle between the inclined surface of the wedge block 71b and the reference line L5 (for example, the first adjustment mechanism 73 mentioned above can be referred to), or a radial adjustment mechanism 76 for adjusting the distance between the inclined surface of the wedge block 71b and the reference line L5 (for example, the second adjustment mechanism 74 mentioned above), etc., which will not be elaborated here.

[0356] Of course, this application is not limited to this. In other embodiments of this application, the force-applying head 71 in "multiple force-applying heads 71 ​​are spaced apart along the direction surrounding the reference line L5, and when the rotating seat 91 rotates, it drives multiple self-rotating rollers 71a to rotate synchronously and in the same direction around the reference line L5" can also adopt other shapes, such as non-rotatable cylindrical or rectangular blocks, etc., but note that one of the surfaces needs to be placed as the force-applying surface 711 with the above-mentioned tilt requirement.

[0357] When "the rotary drive device 9 includes: a rotating seat 91 and a rotary drive mechanism 92, with a force-applying head 71 disposed on the rotating seat 91 to rotate synchronously with the rotating seat 91 around the reference line L5, and the rotary drive mechanism 92 connected to the rotating seat 91 to drive the rotating seat 91 to rotate around the reference line L5", the force-applying head 71 may not be multiple and may be spaced apart along the direction surrounding the reference line L5. For example, referring to FIG34, which is a schematic diagram of a necking device provided in some embodiments of this application, in some embodiments, the force-applying head 71 may also be a necking ring 71c, disposed on the rotating seat 91 to rotate synchronously with the rotating seat 91 around the reference line L5, the necking ring 71c being coaxially arranged with the reference line L5, and the inner circumferential surface of the necking ring 71c being the force-applying surface 711.

[0358] In the above technical solution, the necking ring 71c is coaxially set with the reference line L5, allowing it to be positioned around the end of the workpiece 300 to be necked. This enables the necking ring 71c to apply uniform extrusion force across the entire circumferential range of the workpiece 300 during the necking process, thereby improving the stability and force uniformity of the workpiece 300 during the necking process, reducing the risk of deformation of the workpiece 300 due to uneven force application, and thus improving the necking yield. Furthermore, since the force application head 71 is a necking ring 71c, compared to multiple rotating rollers 71a, only one necking ring 71c is needed to complete the necking process. This simplifies installation and debugging, and facilitates disassembly and replacement, helping to reduce operational difficulty and manufacturing costs.

[0359] When "the distance J between the force-applying surface 711 and the reference line L5 gradually increases along the direction from the first side 651 to the second side 652, and the feed drive device 8 drives at least one of the clamping device 6 and the force-applying head 71 to feed along the extension direction of the reference line L5," in some embodiments, referring again to FIG26, the feed drive device 8 may include: an axial feed drive mechanism 81, which drives the force-applying head 71 to feed along the extension direction of the reference line L5. Thus, since the axial feed drive mechanism 81 drives the force-applying head 71 to move axially, during the necking process of the workpiece 300, axial movement of the workpiece 300 is not required, thereby simplifying the clamping device.

[0360] It is worth noting that the specific configuration of the axial feed drive mechanism 81 is not limited. For example, referring to Figure 35, which is a schematic diagram of a necking device provided in some embodiments of this application, when "the rotary drive device 9 includes a rotating seat 91, and the force-applying head 71 is disposed on the rotating seat 91 to rotate synchronously with the rotating seat 91 around the reference line L5", the axial feed drive mechanism 81 may include a first feed drive mechanism 81a. The first feed drive mechanism 81a is disposed between the rotating seat 91 and the force-applying head 71 to drive the force-applying head 71 to feed relative to the rotating seat 91 along the extension direction of the reference line L5. Thus, the entire rotating seat 91 does not need to be fed axially, thereby reducing the driving force required for the first feed drive mechanism 81a.

[0361] For example, referring to Figure 36, which is a schematic diagram of a necking device provided in some embodiments of this application, when "the rotary drive device 9 includes a rotating seat 91, and the force-applying head 71 is disposed on the rotating seat 91 to rotate synchronously with the rotating seat 91 around the reference line L5", the axial feed drive mechanism 81 may also include a second feed drive mechanism 81b. The second feed drive mechanism 81b is connected to the rotating seat 91 to drive the rotating seat 91 and the force-applying head 71 to feed synchronously along the extension direction of the reference line L5. This simplifies the connection between the rotating seat 91 and the force-applying head 71, facilitates the installation of an adjustment mechanism between the rotating seat 91 and the force-applying head 71 to adjust the position or angle of the force-applying head 71, and also facilitates the routing of the second feed drive mechanism 81b.

[0362] Referring to Figure 37, which is a schematic diagram of a necking device provided in some embodiments of this application, in some embodiments, the feed drive device 8 may further include a radial feed drive mechanism 82, which drives the force application head 71 to feed in a direction perpendicular to the reference line L5.

[0363] Therefore, by setting a radial feed drive mechanism 82, the force application head 71 is driven to feed in a direction perpendicular to the reference line L5, so that the feed direction of the force application head 71 includes the radial direction along the workpiece 300. This makes the drive control of the necking more flexible and can meet more necking requirements.

[0364] In some embodiments, when the feed drive device 8 includes a radial feed drive mechanism 82, which drives the force-applying head 71 to feed in a direction perpendicular to the reference line L5, the necking device 200 may further include a rotary drive device 9, which drives at least one of the force-applying head 71 and the clamping device 6 to rotate around the reference line L5. The configuration of the rotary drive device 9 and the force-applying head 71 can be referred to the above description and will not be repeated here. Furthermore, the feed drive device 8 may also include an axial feed drive mechanism 81, in which case the force-applying head 71 can be driven to move in multiple directions, including axial, radial, and circumferential.

[0365] Please refer again to Figures 23-25. In some embodiments, when the distance J between the force-applying surface 711 and the baseline L5 is inclined in a direction that gradually increases from the first side 651 to the second side 652, the force-applying surface 711 extends in a straight line in the direction from the first side 651 to the second side 652. In the above technical solution, since the force-applying surface 711 extends in a straight line in the direction from the first side 651 to the second side 652, the processing of the force-applying surface 711 can be simplified, the structural complexity of the force-applying head 71 can be reduced, and the installation position of the force-applying head 71 can be easily positioned, improving assembly efficiency. When the force-applying surface 711 extends in a straight line, the movement trajectory and necking extrusion force of the force-applying head 71 can be more easily controlled, thereby reducing the problem of poor necking caused by errors. Of course, this application is not limited to this. For example, in other embodiments, the force-applying surface 711 can also be set to extend along a curve or a broken line in the direction from the first side 651 to the second side 652, etc.

[0366] Please refer again to Figures 23-25. In some embodiments, the angle γ between the force-applying surface 711 and the baseline L5 is 1°-30°. That is, 1°≤γ≤30°. For example, γ can be 1°, 5°, 10°, 15°, 20°, 25°, 30°, etc.

[0367] In the above technical solution, since the angle γ between the force-applying surface 711 and the reference line L5 is greater than or equal to 1°, the force-applying surface 711 can gradually move away from the central axis L2 in the direction from the first side 651 to the second side 652. This facilitates the force-applying surface 711 pressing the workpiece 300 to narrow during axial feeding. Furthermore, since the angle γ between the force-applying surface 711 and the reference line L5 is less than or equal to 30°, the angle between the force-applying surface 711 and the central axis L2 is relatively small, which helps to ensure a smooth transition between the narrowed and unnarrowed portions of the workpiece 300, guaranteeing the structural strength of the narrowed portion. Therefore, when the angle between the force-applying surface 711 and the central axis L2 is 1°-30°, it facilitates the fit between the force-applying surface 711 and the workpiece 300 and ensures the structural strength of the narrowed portion. Furthermore, the range of the angle γ can be limited to 1°-5°, which further helps to guarantee the structural strength of the narrowed position.

[0368] Please refer again to Figures 23-25. In some embodiments, when the distance J between the force-applying surface 711 and the reference line L5 gradually increases along the direction from the first side 651 to the second side 652, the dimension W of the force-applying surface 711 in the extension direction of the reference line L5 is 5mm-30mm. In this case, the force-applying surface 711 can extend in a straight line or along a curve in the direction from the first side 651 to the second side 652, and the angle γ between the force-applying surface 711 and the reference line L5 can be 1°-30° or exceed this range. For example, W can be 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, etc.

[0369] In the above technical solution, since the dimension W of the force-applying surface 711 in the extension direction of the reference line L5 is greater than or equal to 5mm, the dimension of the force-applying surface 711 in the extension direction of the reference line L5 is not too small, which is conducive to its cooperation with the workpiece 300 and has a sufficient area to extrude and compress the workpiece 300, which is conducive to adapting to various compression requirements. Furthermore, since the dimension W of the force-applying surface 711 in the extension direction of the reference line L5 is less than or equal to 30mm, the dimension of the force-applying surface 711 in the extension direction of the reference line L5 is not too large, which can reduce the manufacturing cost of the force-applying head 71, reduce the cost of the compression equipment 200, and save the space occupied by the force-applying head 71, which is conducive to the compact and miniaturized design of the compression equipment 200.

[0370] Referring again to Figure 24, in some embodiments, the clamping device 6 includes an end-face clamping mechanism 61. The end-face clamping mechanism 61 includes a first clamping member 611, which is disposed on the second side 652. The abutting surface of the first clamping member 611 is perpendicular to the reference line L5 to abut the workpiece 300 along its axial direction, that is, abutting the axial end face of the workpiece 300 away from the force-applying head 71. Thus, by abutting the workpiece 300 only along its axial direction at the axial end away from the force-applying head 71, the concentricity requirement can be reduced, which is beneficial for quick clamping. Moreover, the end face abutting the workpiece 300 can counteract the axial force applied to the workpiece 300 by the force-applying head 71, thereby preventing the workpiece 300 from falling out of the clamping position and ensuring that the necking process can be carried out smoothly.

[0371] Referring again to Figure 24, in some embodiments, the end face clamping mechanism 61 further includes a first clamping drive mechanism 612, which is connected to the first clamping member 611 to drive the end face clamping device 6 to move along the extension direction of the reference line L5. Thus, after clamping, the first clamping drive mechanism 612 can push the first clamping member 611 to move the workpiece 300 along the extension direction of the reference line L5 to approach the narrowing device 7. Conversely, when clamping the workpiece 300, the first clamping drive mechanism 612 can push the first clamping member 611 away from the narrowing device 7 along the extension direction of the reference line L5, thereby providing more space for the clamping operation of the workpiece 300. Furthermore, in some embodiments, the first clamping drive mechanism 612 can be used instead of the axial feed drive mechanism 81.

[0372] Referring again to Figure 24, in some embodiments, the clamping device 6 further includes a foolproof protection mechanism 62, which is arranged along the baseline L5 with the end-face clamping mechanism 61 and is used to limit the end-face clamping mechanism 61 in the extension direction along the baseline L5. This avoids the risk of the workpiece 300 colliding with the narrowing device 7 when the first clamping drive mechanism 612 drives the first clamping member 611 to move beyond a preset value, thus protecting the workpiece 300. For example, the end-face clamping mechanism 61 may also include a stop member 613 that is stationary relative to the first clamping member 611. When the first clamping drive mechanism 612 drives the first clamping member 611 to a preset position, the stop member 613 abuts against the foolproof protection mechanism 62 in the extension direction along the baseline L5, thereby limiting the movement and keeping the first clamping member 611 at its limit position.

[0373] Referring again to Figure 24, in some embodiments, the clamping device 6 includes a radial clamping mechanism 63, which includes multiple second clamping members 631. These second clamping members 631 are spaced apart along the direction surrounding the reference line L5 on the periphery of the workpiece space 65. The abutting surface of the second clamping members 631 is parallel to the reference line L5 and is used to radially abut against the outer peripheral surface of the workpiece 300. In the above technical solution, the second clamping members 631 apply radial clamping force to multiple circumferentially spaced positions on the outer periphery of the workpiece 300, thereby firmly clamping the outer periphery of the workpiece 300 during the necking process. This prevents the workpiece 300 from rotating or radially displacing during the necking process, ensuring that the necking process can proceed smoothly and improving the necking quality.

[0374] Referring again to Figure 24, in some embodiments, the radial clamping mechanism 63 includes a second clamping drive mechanism 632, which is connected to the second clamping member 631 to drive the second clamping member 631 to move radially along the workpiece space 65. Thus, the second clamping member 631 can be driven by the second clamping drive mechanism 632 to achieve automatic clamping, and it can adapt to clamping workpieces 300 with different outer diameters.

[0375] Referring again to Figures 23 and 24, in some embodiments, the clamping device 6 and the narrowing device 7 are arranged in a horizontal direction perpendicular to the direction of gravity, so that the central axis L2 of the workpiece space 65 is perpendicular to the direction of gravity G. This avoids the risk of damage to the device below if the upper device is unstable when the narrowing device 7 and clamping device 6 are arranged along the direction of gravity, and also facilitates assembly and adjustment.

[0376] The following describes a specific embodiment of using a necking device 200 according to an embodiment of this application to neck the end of a cylindrical battery 102.

[0377] The cylindrical battery 102 includes a housing 1 and an end cap 2. At least one axial end of the housing 1 is formed as an open end 1a. Before the necking process, the end cap 2 is first placed on the open end 1a, and then the housing 1 and the end cap 2 are welded from the side of the housing 1 so that the housing 1 and the end cap 2 are connected by a weld mark 3 around the end cap 2 along the circumference of the housing 1 to form a housing unit Q. The two axial sides of the housing unit Q are a first side 651 and a second side 652, respectively. The central axis of the housing unit Q is collinear with the reference line L5. The necking device 200 can perform necking processing on the axial end of the housing unit Q with the weld mark 3, so that the weld mark 3 is radially recessed into the cylindrical surface S where the outer circumferential surface 1c of the housing 1 is located.

[0378] The necking device 200 includes: a clamping device 6, a necking device 7, a feed drive device 8, and a rotary drive device 9. The rotary drive device 9 includes a rotating base 91 and a rotary drive mechanism 92. The rotary drive mechanism 92 is connected to the rotating base 91 to drive the rotating base 91 to rotate around the reference line L5. Multiple necking devices 7 are arranged at intervals along the direction surrounding the reference line L5. When the rotating base 91 rotates, it drives multiple force-applying heads 71 ​​to rotate synchronously and in the same direction around the reference line.

[0379] The necking device 7 includes a force-applying head 71, a roller base 72, and a first adjusting mechanism 73. The first adjusting mechanism 73 includes an adjusting seat 731, a connecting shaft 732, and a locking element 733. The force-applying head 71 is a self-rotating roller 71a and is rotatably mounted on the roller base 72. The roller base 72 is rotatably mounted on the adjusting seat 731 via the connecting shaft 732. The adjusting seat 731 is located on a rotating seat 91 to rotate synchronously with the rotating seat 91 around the reference line L5, thereby allowing the force-applying head 71 to rotate synchronously with the rotating seat 91 around the reference line L5. The feed drive device 8 includes an axial feed drive mechanism 81, which includes a second feed drive mechanism 81b connected to the rotating seat 91.

[0380] The outer circumferential surface of the rotating roller 71a forms the force-applying surface 711. The axis L4 of the connecting shaft 732 is perpendicular to the reference line L5. By rotating the roller base 72 around the connecting shaft 732 relative to the adjusting seat 731, the tilt angle of the axis L3 of the rotating roller 71a relative to the reference line L5 can be adjusted. The locking member 733 is used to lock the relative angle between the roller base 72 and the adjusting seat 731, thereby adjusting the included angle γ between the force-applying surface 711 and the reference line L5.

[0381] The clamping device 6 includes an end-face clamping mechanism 61 and a radial clamping mechanism 63. The end-face clamping mechanism 61 includes a first clamping member 611, and the radial clamping mechanism 63 includes a second clamping member 631. A force-applying head 71 is disposed on a first side 651 of the housing unit Q, and the first clamping member 611 is disposed on a second side 652 of the housing unit Q to abut against the axial end face of the housing unit Q along the axial direction of the housing unit Q. There are multiple second clamping members 631, which are distributed at intervals around the circumference of the housing unit Q in the direction surrounding the reference line L5. The second clamping members 631 clamp the outer circumferential surface of the housing unit Q radially.

[0382] When the necking device 200 is working, the clamping device 6 first clamps the housing unit Q to ensure that the distance J between the force application surface 711 of the force application head 71 and the reference line L5 gradually increases along the direction from the first side 651 to the second side 652. The second feed drive mechanism 81b drives the rotating seat 91 to feed along the direction from the first side 651 to the second side 652 in the extension direction of the reference line L5, so that the force application surface 711 presses the shaft end of the housing unit Q with the weld mark 3 to achieve necking of the weld mark 3 position, so that the weld mark 3 is radially retracted into the cylindrical surface S where the outer peripheral surface 1c of the housing 1 is located.

[0383] Thus, the necking device 7 and the rotary drive device 9 are the core mechanisms. The necking device 7 mainly includes a rotating roller 71a, a roller base 72, and a first adjustment mechanism 73. The roller base 72 is designed with bearings so that the rotating roller 71a can rotate freely. The roller base 72 is connected to the first adjustment mechanism 73 so that the angle between the axis L3 of the rotating roller 71a and the reference line L5 is adjustable from 1 to 5 degrees. The rotary drive device 9 mainly includes a rotating seat 91 and a rotary drive mechanism 92. The necking device 7 is installed on the rotating seat 91 of the rotary drive device 9. During operation, the rotating seat 91 rotates under the drive of the rotary drive mechanism 92. The rotating roller 71a is squeezed against the end of the cylindrical battery 102 to be processed, generating static friction to drive the rotating roller 71a to rotate. The outer circumferential surface of the rotating roller 71a is the force application surface 711. As the rotating seat 91 revolves, it gradually rolls over the weld mark 3 of the cylindrical battery 102 in the circumferential direction, thereby achieving the purpose of rolling and necking. While the rotating seat 91 revolves, it also feeds along the axial direction of the cylindrical battery 102 under the drive of the second feed drive mechanism 81b. The larger the feed stroke, the larger the size of the necking and shaping. Therefore, the necking and shaping size can be controlled by the feed amount of the second feed drive mechanism 81b.

[0384] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0385] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cylindrical battery, wherein, include: A housing, wherein at least one end of the housing in the axial direction is formed as an open end; An end cap is provided on the open end and is connected to the housing by a solder joint. The solder joint surrounds the end cap circumferentially around the housing and is radially recessed within the cylindrical surface of the outer circumferential surface of the housing.

2. The cylindrical battery according to claim 1, wherein, Along the axial direction of the housing from the housing to the end cap, the inward dimension of the solder mark relative to the cylindrical surface along the radial direction of the housing gradually increases.

3. The cylindrical battery according to claim 2, wherein, On the axial section of the cylindrical battery, the outer contour of the solder mark includes a curved segment.

4. The cylindrical battery according to claim 2, wherein, On the axial section of the cylindrical battery, the outer contour of the solder mark includes a slanted segment, one end of which is connected to the housing, and the other end is inclined towards the end cap along a direction that gradually approaches the central axis of the housing.

5. The cylindrical battery according to any one of claims 1-4, wherein, On the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The inner contour line of the solder mark includes a first contour segment connecting the shell connection point and the maximum melting point of the solder mark. The first contour segment is divided into a first segment and a second segment arranged sequentially from the shell connection point to the maximum melting point. The first segment convexes outward relative to the second segment.

6. The cylindrical battery according to claim 5, wherein, The connection point between the first segment and the second segment is located at the center of the length of the first contour segment.

7. The cylindrical battery according to any one of claims 1-6, wherein, On the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The point on the outer contour line of the solder mark that is directly opposite the maximum melting point of the solder mark along the radial direction is the dividing point. The outer contour line includes a second contour segment connecting the cap connection point and the dividing point. Along the axial direction of the housing from the housing to the end cap, the inward dimension of the second contour segment relative to the cylindrical surface along the radial direction of the housing gradually increases.

8. The cylindrical battery according to any one of claims 1-6, wherein, On the axial section of the cylindrical battery, the two endpoints of the outer contour line of the solder mark are the shell connection point connected to the housing and the cap connection point connected to the end cap, respectively. The point on the outer contour line of the solder mark that is directly opposite the maximum melting point of the solder mark along the radial direction is the dividing point. The outer contour line includes a third contour segment connecting the shell connection point and the dividing point. Along the axial direction of the shell from the shell to the end cap, the radial inward dimension of the third contour segment relative to the cylindrical surface of the shell gradually increases.

9. The cylindrical battery according to claim 7 or 8, wherein, The dimension by which the dividing point is radially recessed relative to the shell connection point along the shell is the first dimension D1, and the dimension by which the cover connection point is radially recessed relative to the dividing point along the shell is the second dimension D2, where D2 > D1 ≥ 0 μm.

10. The cylindrical battery according to any one of claims 7-9, wherein, The distance between the dividing point and the shell connection point along the axial direction of the shell is the first distance L1, and the distance between the dividing point and the cover connection point along the axial direction of the shell is the second distance L2, where L1 > L2.

11. The cylindrical battery according to any one of claims 1-10, wherein, The end cap includes an edge portion and a central portion. The edge portion overlaps the axial side of the opening end of the housing, and the central portion extends into the opening end and is interference-fitted with the opening end. The housing and the edge portion are side-welded to form the weld mark.

12. The cylindrical battery according to claim 11, wherein, The maximum penetration depth of the weld mark along the radial direction of the shell is H, and the wall thickness of the shell is E, where 1.2E≥H≥0.7E; the wall thickness of the edge portion at the point of maximum penetration depth of the weld mark directly opposite the axial direction of the shell is L3, where 2E≥L3≥0.5E.

13. The cylindrical battery according to any one of claims 1-12, wherein, Also includes: A protective layer comprising a first covering portion covering the periphery of the solder stamp, wherein at least a portion of the first covering portion is radially recessed within the cylindrical surface of the housing.

14. The cylindrical battery according to claim 13, wherein, A portion of the first covering portion protrudes radially beyond the cylindrical surface, and the protrusion height radially along the housing does not exceed 150 micrometers.

15. The cylindrical battery according to claim 13 or 14, wherein, The protective layer includes a second covering portion located on the side of the end cap away from the housing along the axial direction of the housing and covering the end cap and / or the solder mark, the second covering portion being connected to the first covering portion.

16. The cylindrical battery according to any one of claims 13-15, wherein, The protective layer includes a third covering portion, which covers the periphery of the housing and is connected to the first covering portion.

17. The cylindrical battery according to any one of claims 13-15, wherein, Also includes: A protective film, which is a pre-formed film and covers the periphery of the housing, the area covered by the protective film is called the coating area, the area covered by the protective layer is called the coating area, and the coating area is located at one end of the coating area along the axial direction of the housing.

18. The cylindrical battery according to claim 17, wherein, On the axial section of the cylindrical battery, the distance between the outer contour line of the protective film and the outer contour line of the protective layer in the radial direction of the casing does not exceed 150 micrometers.

19. The cylindrical battery according to any one of claims 17-18, wherein, The housing is a nickel-plated housing, and the protective layer is a rust-proof layer.

20. The cylindrical battery according to claim 19, wherein, The rust-proof layer is at least one of the following: a UV adhesive printing layer, an ink coating layer, and a metal plating layer.

21. The cylindrical battery according to any one of claims 1-20, wherein, The diameter to height ratio of the cylindrical battery is 46mm / 80mm; or 46mm / 95mm; or 46mm / 120mm.

22. A battery device, wherein, Includes the cylindrical battery according to any one of claims 1-21.

23. An electrical appliance, wherein, Includes the battery device according to claim 22.

24. A method for processing a cylindrical battery, wherein, include: A housing and an end cap are provided, wherein at least one axial end of the housing is formed as an open end; The end cap is placed over the opening end; The housing and the end cap are welded from the side of the housing so that the housing and the end cap are connected by a weld mark around the end cap in the circumferential direction of the housing to form a housing unit; The shaft end of the housing unit with the solder mark is reduced in diameter, so that the solder mark is radially recessed within the cylindrical surface of the outer circumference of the housing.

25. The method for processing a cylindrical battery according to claim 24, wherein, The specific steps of reducing the neck of the shaft end with the solder mark on the housing unit include: The shaft end of the housing unit with the solder mark is squeezed to perform a necking process.

26. The method for processing a cylindrical battery according to claim 25, wherein, The step of pressing the shaft end of the housing unit with the solder mark to perform a necking process specifically includes: Simultaneously apply constriction extrusion force to multiple positions spaced circumferentially along the housing at the shaft end, and cause the multiple positions where the extrusion force is applied to move synchronously and in the same direction along the circumference of the housing.

27. The method for processing a cylindrical battery according to claim 25 or 26, wherein, The step of pressing the shaft end of the housing unit with the solder mark to perform a necking process specifically includes: Provides a force-applying head with a force-applying surface; The force-applying head is positioned such that the force-applying surface faces the shaft end, and the force-applying surface is tilted in a direction gradually away from the central axis of the housing along the direction from the end cap to the housing; The force-applying head is pushed to feed along the axial direction of the housing so that the shaft end is pressed by the force-applying surface.

28. A method for processing a cylindrical battery according to any one of claims 24-27, wherein, The procedure prior to the step of reducing the neck of the shaft end of the housing unit having the solder mark includes: Radial clamping forces are applied at multiple circumferentially spaced locations on the outer periphery of the housing unit, the radial clamping forces pointing radially toward the interior of the housing; An axial support force is applied to the end of the housing unit that is axially away from the end cap, the axial support force being axially directed toward the end cap.

29. A method for processing a cylindrical battery according to any one of claims 24-28, wherein, Following the step of reducing the neck of the shaft end with the solder mark on the housing unit, the method further includes: A protective layer is applied to the outside of the housing unit, such that the protective layer at least covers the solder marks.

30. The method for processing a cylindrical battery according to claim 29, wherein, The specific steps for applying a protective layer to the housing unit are as follows: applying a protective layer to the housing unit by UV adhesive printing.

31. The method for processing a cylindrical battery according to claim 29 or 30, wherein, A protective layer is applied to the outside of the housing unit, such that the protective layer covers the solder mark and also covers at least the edge of the shaft end on the axial side away from the housing.

32. A method for processing a cylindrical battery according to any one of claims 29-31, wherein, A protective layer is applied to the outside of the housing unit, so that the protective layer covers the solder mark and also covers the outer peripheral surface of the housing.

33. The method for processing a cylindrical battery according to any one of claims 29-31, wherein, The step of covering the housing unit with a protective layer further includes: A protective film is applied to the outer periphery of the housing. The protective film is a pre-formed film, and the area covered by the protective film is called the coating area. The area covered by the protective layer is called the coating area. The coating area is located at one end of the coating area along the axial direction of the housing.

34. A method for processing a cylindrical battery according to any one of claims 24-33, wherein, The end cap includes an edge portion and a central portion, and the step of placing the end cap on the open end specifically includes: The edge portion overlaps the axial side of the opening end of the housing; The central portion extends into the opening end and is interference-fitted with the opening end.

35. A necking device, wherein, The necking device is used to reduce the diameter of the shaft end of a cylindrical workpiece. A clamping device is used to clamp the workpiece. The space occupied by the workpiece clamped by the clamping device is the workpiece space. The two axial sides of the workpiece space are the first side and the second side, respectively. The central axis of the workpiece space is the reference line. A necking device, comprising a force-applying head disposed on the first side and including a force-applying surface for necking the shaft end of the workpiece, wherein the distance between the force-applying surface and the reference line gradually increases along the direction from the first side to the second side; A feed drive device drives at least one of the force-applying head and the clamping device to perform a feed motion along the extension direction of the reference line, so that the force-applying surface presses the shaft end of the workpiece to achieve narrowing. A rotary drive device that drives at least one of the force-applying head and the clamping device to rotate about the reference line.

36. The necking device according to claim 35, wherein, The rotary drive device includes: A rotating base, wherein the force-applying head is mounted on the rotating base to rotate synchronously with the rotating base around the reference line; A rotation drive mechanism is connected to the rotating seat to drive the rotating seat to rotate around the reference line.

37. The necking device according to claim 36, wherein, The force-applying heads are multiple and spaced apart along the direction surrounding the baseline. When the rotating seat rotates, it drives the multiple force-applying heads to rotate synchronously and in the same direction around the baseline.

38. The necking device according to any one of claims 35-37, wherein, The narrowing device includes: The roller base is provided, and the force-applying head is a self-rotating roller that is rotatably mounted on the roller base. The outer circumferential surface of the self-rotating roller constitutes the force-applying surface.

39. The necking device according to claim 38, wherein, The rotating roller is in the shape of a cone.

40. The necking device according to claim 38, wherein, The rotating roller is cylindrical.

41. The necking device according to any one of claims 38-40, wherein, The rotating roller is detachably mounted on the roller base.

42. The necking device according to any one of claims 38-41, wherein, The narrowing device includes a first adjustment mechanism connected to the roller base for adjusting the tilt angle of the axis of the rotating roller relative to the reference line.

43. The necking device according to claim 42, wherein, The first adjustment mechanism includes an adjustment seat, a connecting shaft, and a locking member. The roller base is rotatably mounted on the adjustment seat via the connecting shaft. The locking member is used to lock the relative angle between the roller base and the adjustment seat. The axis of the connecting shaft intersects the reference line.

44. The necking device according to any one of claims 41-43, wherein, The rotary drive device includes: A rotating seat, wherein the roller base is disposed on the rotating seat to rotate synchronously with the rotating seat around the reference line; A rotation drive mechanism is connected to the rotating seat to drive the rotating seat to rotate around the reference line.

45. The necking device according to claim 44, wherein, The narrowing device includes a second adjustment mechanism connected between the rotating seat and the roller base for adjusting the position of the roller base relative to the rotating seat along a line perpendicular to the reference line.

46. ​​The necking device according to any one of claims 35-37, wherein, The force-applying head is a wedge-shaped block, and the inclined surface of the wedge-shaped block constitutes the force-applying surface.

47. The necking device according to any one of claims 35-36, wherein, The force-applying head is a constricted ring, which is coaxially arranged with the baseline, and the inner circumferential surface of the constricted ring is the force-applying surface.

48. The necking device according to any one of claims 35-46, wherein, The feed drive device includes: A radial feed drive mechanism is provided to drive the force-applying head to feed in a direction perpendicular to the baseline.

49. The necking device according to any one of claims 35-48, wherein, The feed drive device includes: An axial feed drive mechanism is provided to drive the force-applying head to feed along the extension direction of the reference line.

50. The necking device according to claim 49, wherein, The rotary drive device includes: a rotating seat, and the force-applying head is disposed on the rotating seat to rotate synchronously with the rotating seat around the reference line; The axial feed drive mechanism includes a first feed drive mechanism, which is located between the rotating seat and the force-applying head to drive the force-applying head to feed relative to the rotating seat along the extension direction of the reference line.

51. The necking device according to claim 49, wherein, The rotary drive device includes: a rotating seat, and the force-applying head is disposed on the rotating seat to rotate synchronously with the rotating seat around the reference line; The axial feed drive mechanism includes a second feed drive mechanism, which is connected to the rotating seat to drive the rotating seat and the force application head to feed synchronously along the extension direction of the reference line.

52. The necking device according to any one of claims 35-51, wherein, The force-applying surface extends in a straight line from the first side and the second side.

53. The necking device according to claim 51, wherein, The angle between the force-applying surface and the baseline is 1°-30°.

54. The necking device according to any one of claims 35-53, wherein, The dimension of the force-applying surface in the extension direction of the baseline is 5mm-30mm.

55. The necking device according to any one of claims 35-54, wherein, The clamping device includes: An end face clamping mechanism, the end face clamping mechanism including a first clamping member, the first clamping member being disposed on the second side, the abutting surface of the first clamping member being perpendicular to the reference line for axially abutting the axial end face of the workpiece away from the force-applying head.

56. The necking device according to claim 55, wherein, The end face clamping mechanism further includes: A first clamping drive mechanism is connected to the first clamping member to drive the end face clamping device to move along the extension direction of the reference line.

57. The necking device according to claim 56, wherein, The clamping device includes: A foolproof protection mechanism is provided, wherein the foolproof protection mechanism and the end face clamping mechanism are arranged along the reference line, and the end face clamping mechanism is used to limit the extension direction of the end face clamping mechanism along the reference line.

58. The necking device according to any one of claims 35-57, wherein, The clamping device includes: A radial clamping mechanism includes a second clamping member, which is a plurality of such clamping members and is spaced apart on the periphery of the workpiece space along a direction surrounding the reference line. The abutting surface of the second clamping member is parallel to the reference line and is used to abut the outer peripheral surface of the workpiece radially.

59. The necking device according to claim 58, wherein, The radial clamping mechanism includes: A second clamping drive mechanism is connected to the second clamping member to drive the second clamping member to move radially along the workpiece space.

60. The necking device according to any one of claims 35-59, wherein, The clamping device and the narrowing device are arranged in a horizontal direction perpendicular to the direction of gravity, so that the central axis of the workpiece space is perpendicular to the direction of gravity.

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