Necking device

Abstract

A necking device (10), comprising a rotating base (100) and a plurality of rolling assemblies (200), wherein the plurality of rolling assemblies are arranged on the rotating base around the rotation axis of the rotating base. Each rolling assembly comprises a freely rotatable pressing roller (210), and pressing rollers of the plurality of rolling assemblies are configured to work in conjunction when a workpiece (20) approaches the rotating base, to roll the workpiece. The pressing roller comprises a rolling surface (211) for rolling the workpiece, wherein the rolling surface intersects with a first cross section of the pressing roller to form two intersection lines, and the first cross section passes through the rotation axis of the pressing roller and the rotation axis of the rotating base. An intersection line, closest to the rotation axis of the rotating base, among the two intersection lines is a first intersection line (2111), and the distance between the first intersection line and the rotation axis of the rotating base gradually increases in the direction from the rotating base toward the workpiece. The necking device can perform necking on a housing, so that the outer contour of the end portion of the housing close to an opening is reduced, thereby reducing a local outward expansion dimension of the housing due to interference fit between an end cover and the housing, thus facilitating reduction of the size of a battery cell and improvement of the energy density of the battery cell.

Description

Closure device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application No. 202510070114.1 entitled “Narrowing Device”, filed on January 16, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and more specifically, to a necking device. Background Technology

[0004] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as battery life, discharge capacity, and charge / discharge rate. Additionally, battery energy density also needs to be considered. However, the energy density of current batteries is relatively low. Summary of the Invention

[0005] The purpose of this application is to provide a necking device that aims to improve the problem of low energy density in batteries in related technologies.

[0006] In a first aspect, embodiments of this application provide a necking device for necking a workpiece. The necking device includes a rotating base and a plurality of roller pressing assemblies. The plurality of roller pressing assemblies are arranged around the rotation axis of the rotating base. Each roller pressing assembly includes a self-rotating pressure roller. The pressure rollers of the plurality of roller pressing assemblies are configured to cooperate in pressing the workpiece when it approaches the rotating base. The pressure roller has a pressing surface for pressing the workpiece. The pressing surface intersects with a first cross-section of the pressure roller to form two intersecting lines. The first cross-section passes through the rotation axis of the pressure roller and the rotation axis of the rotating base. The intersecting line closest to the rotation axis of the rotating base is the first intersecting line. The distance between the first intersecting line and the rotation axis of the rotating base gradually increases along the direction from the rotating base toward the workpiece.

[0007] In the above technical solution, the necking device includes a rotating base and multiple roller pressing components. The rotating base can rotate around its own axis, thereby driving the multiple roller pressing components to rotate. Each roller pressing component includes a pressure roller that can rotate around its own axis. When pressing the workpiece, the pressure roller not only revolves with the rotating base but also rotates on its own axis, which helps to uniformly neck the workpiece, improve the necking quality, and reduce friction on the workpiece, thus reducing the risk of scratching the workpiece. The distance between the first intersection line and the rotation axis of the rotating base gradually increases along the direction from the rotating base to the workpiece. In this way, when the workpiece approaches the rotating base, it can gradually come into contact with the roller pressing surface. Under the action of the pressure roller, the outer contour of the part of the workpiece in contact with the pressure roller gradually decreases, which helps to make the necked part of the workpiece transition smoothly with the unnecked part. In addition, the closer the workpiece is to the rotating base, the greater the degree of necking. By adjusting the distance between the workpiece and the rotating base, the degree of necking can be adjusted to meet various necking requirements. When the workpiece is a battery cell or the casing of a battery cell, the necking device can neck the casing, thereby reducing the outer contour of the end of the casing near the opening. This reduces the size of the casing that would otherwise be caused by the interference fit between the end cap and the casing, which helps to reduce the volume of the battery cell and increase its energy density.

[0008] As an optional technical solution in this application embodiment, the roller pressing assembly includes a first adjusting seat and a locking member. The first adjusting seat is rotatably disposed on the rotating seat, and the pressure roller is rotatably disposed on the first adjusting seat about its own axis. The rotation axis of the first adjusting seat intersects the rotation axis of the rotating seat, and the rotation axis of the first adjusting seat intersects the rotation axis of the pressure roller. The locking member is used to unlockably lock the first adjusting seat and the rotating seat.

[0009] In the above technical solution, the locking component has an unlocked state and a locked state. When the locking component is in the unlocked state, it unlocks the first adjusting seat and the rotating seat, allowing the first adjusting seat to rotate relative to the rotating seat, thus facilitating the adjustment of the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat. When the locking component is in the locked state, it locks the first adjusting seat and the rotating seat, preventing the first adjusting seat from rotating relative to the rotating seat, thus facilitating the pressure roller to press the workpiece. By setting the first adjusting seat and the locking component, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat can be adjusted as needed, meeting more necking requirements and improving the adaptability of the necking device to different necking needs.

[0010] As an optional technical solution in this application embodiment, the roller pressing surface is a cylindrical surface, and the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is an acute angle.

[0011] In the above technical solution, when the roller surface is cylindrical, the pressure roller can be cylindrical. To make the distance between the first intersection line and the rotation axis of the rotating seat gradually increase along the direction from the rotating seat to the workpiece, the pressure roller can be arranged at an angle, that is, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is an acute angle. In addition, when the roller surface is cylindrical, the increase in the distance between the first intersection line and the rotation axis of the rotating seat along the direction from the rotating seat to the workpiece is uniform, so that the degree of narrowing changes uniformly as the workpiece approaches the rotating seat, thereby facilitating the control of the narrowing quality and degree, and helping to increase the smoothness of the narrowing position of the workpiece.

[0012] As an optional technical solution in this application embodiment, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is α, which satisfies: 0 < α ≤ 30°.

[0013] In the above technical solution, when a > 0, and the roller surface is cylindrical, the pressure roller is tilted, causing the distance between the first intersection line and the rotation axis of the rotating seat to gradually increase along the direction from the rotating seat to the workpiece, thus facilitating the roller pressing of the workpiece. Furthermore, it reduces the risk of leaving indentations on the workpiece. When a ≤ 30°, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is small, which helps to ensure a smooth transition between the constricted and unconstricted portions of the workpiece. Therefore, when 0 < a ≤ 30°, the roller pressing quality can be improved, the risk of leaving indentations on the workpiece can be reduced, and the transition between the constricted and unconstricted portions of the workpiece can be made smooth.

[0014] As an optional technical solution in this application embodiment, 1°≤a≤8°.

[0015] In the above technical solution, when a > 1°, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is relatively large, which can further reduce the risk of leaving indentations on the workpiece. When a ≤ 8°, the angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is not too large, which helps to make the transition between the constricted part and the unconstricted part of the workpiece smoother. Therefore, when 1° ≤ a ≤ 8°, the roller pressing quality can be improved, the risk of leaving indentations on the workpiece can be further reduced, and the transition between the constricted part and the unconstricted part of the workpiece can be smoother.

[0016] As an optional technical solution in this application embodiment, the roller pressing surface is a conical surface, and the rotation axis of the pressing roller is parallel to the rotation axis of the rotating seat.

[0017] In the above technical solution, when the roller surface is a conical surface, it is only necessary to make the rotation axis of the pressure roller parallel to the rotation axis of the rotating seat. This will allow the distance between the first intersection line and the rotation axis of the rotating seat to gradually increase along the direction from the rotating seat towards the workpiece. Furthermore, when the roller surface is a conical surface and the rotation axis of the pressure roller is parallel to the rotation axis of the rotating seat, the increase in the distance between the first intersection line and the rotation axis of the rotating seat along the direction from the rotating seat towards the workpiece is uniform. This ensures that the degree of narrowing changes uniformly as the workpiece approaches the rotating seat, thus facilitating control over the quality and degree of narrowing and improving the smoothness of the narrowing position on the workpiece.

[0018] As an optional technical solution in this application embodiment, the pressure roller is detachably connected to the rotating seat.

[0019] In the above technical solution, by detachably connecting the pressure roller to the rotating seat, more necking requirements can be met by replacing pressure rollers with different tapers, which is beneficial to improving the adaptability of the necking device to different necking requirements.

[0020] As an optional technical solution in this application embodiment, the angle between the first intersecting line and the rotation axis of the rotating seat is b, which satisfies: 0 < b ≤ 30°.

[0021] In the above technical solution, when b > 0, the distance between the first intersection line and the rotation axis of the rotating seat gradually increases along the direction from the rotating seat to the workpiece, thus facilitating the rolling of the workpiece. Furthermore, it reduces the risk of leaving indentations on the workpiece. When b ≤ 30°, the angle between the first intersection line and the rotation axis of the rotating seat is small, which helps to ensure a smooth transition between the constricted and unconstricted portions of the workpiece. Therefore, when 0 < b ≤ 30°, the rolling quality can be improved, the risk of leaving indentations on the workpiece can be reduced, and the transition between the constricted and unconstricted portions of the workpiece can be made smooth.

[0022] As an optional technical solution in this application embodiment, 1≤b≤8°.

[0023] In the above technical solution, when b > 1°, the angle between the first intersection line and the rotation axis of the rotating seat is relatively large, which can further reduce the risk of leaving indentations on the workpiece. When b ≤ 8°, the angle between the first intersection line and the rotation axis of the rotating seat is not too large, which helps to make the transition between the constricted portion and the unconstricted portion of the workpiece smoother. Therefore, when 1 ≤ b ≤ 8°, the rolling quality can be improved, the risk of leaving indentations on the workpiece can be further reduced, and the transition between the constricted portion and the unconstricted portion of the workpiece can be smoother.

[0024] As an optional technical solution in this application embodiment, the pressure roller includes a first pressure roller section and a second pressure roller section. The minimum diameter of the second pressure roller section is greater than the maximum diameter of the first pressure roller section. The outer peripheral surface of the first pressure roller section is the pressure roller surface. The outer peripheral surface of the first pressure roller section and the outer peripheral surface of the second pressure roller section are connected by an abutment surface. The abutment surface is used to abut against one end of the workpiece near the rotating seat.

[0025] In the above technical solution, during the roll forming of the workpiece, the roll forming surface can contact the outer peripheral surface of the workpiece, and the abutment surface can abut against the end of the workpiece closest to the rotating seat. This improves the tensile stress distribution of the workpiece during the roll forming process, allowing the workpiece to retain high strength after roll forming. When the workpiece is a battery cell, the roll forming surface can roll the outer peripheral surface of the casing, and the abutment surface can abut against the end cap. This can, to a certain extent, offset the tensile stress of the weld seam generated by the roll forming process on the casing and end cap, resulting in higher connection strength between the casing and end cap.

[0026] As an optional technical solution in this application embodiment, the first roller pressing part is frustum-shaped, the second roller pressing part is cylindrical, and the end face of the second roller pressing part facing the first roller pressing part is the abutting surface; the rotation axis of the pressure roller is parallel to the rotation axis of the rotating seat.

[0027] In the above technical solution, the first roller pressing section is frustum-shaped, and the pressing surface is conical. By simply making the rotation axis of the pressure roller parallel to the rotation axis of the rotating seat, the distance between the first intersection line and the rotation axis of the rotating seat gradually increases along the direction from the rotating seat towards the workpiece. The second roller pressing section is cylindrical, resulting in a larger contact area with the workpiece. This increases the contact area with the workpiece, improves the tensile stress distribution on the workpiece during the rolling process, and ensures that the workpiece retains high strength after rolling.

[0028] As an optional technical solution in this application embodiment, the roller surface is provided with embossing.

[0029] In the above technical solution, by setting embossing on the roller surface, the part of the workpiece in contact with the roller is uniformly roughened, which facilitates the subsequent rust prevention treatment of the workpiece.

[0030] As an optional technical solution in this application embodiment, the size of the roller pressing surface is c, where 5mm≤c≤30mm, along the extension direction of the rotation axis of the pressure roller.

[0031] In the above technical solution, when c ≥ 5mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is relatively large, resulting in a larger necking range, which can adapt to various necking requirements. When the workpiece is a battery cell or its casing, it can reduce the size of the casing's local outward expansion caused by the interference fit between the end cap and the casing. When c ≤ 30mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is not too large. On the one hand, this reduces the manufacturing cost of the roller and the cost of the necking device. On the other hand, the roller is less likely to press on parts of the workpiece that do not require necking, reducing unnecessary wear on the workpiece. When the workpiece is a battery cell or its casing, the roller is less likely to press on parts of the casing that are not locally outwardly expanded, reducing unnecessary wear on the casing. Therefore, when 5mm ≤ c ≤ 30mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is moderate, allowing for a larger necking range without pressing on parts of the workpiece that do not require necking.

[0032] As an optional technical solution in this application embodiment, 10mm≤c≤20mm.

[0033] In the above technical solutions, when c ≥ 10 mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is larger, resulting in a wider necking range and adaptability to various necking requirements. When the workpiece is a battery cell or its casing, it reduces the size of the casing's localized outward expansion caused by the interference fit between the end cap and the casing. When c ≤ 20 mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is not excessively large. On the one hand, this further reduces the manufacturing cost of the roller and the cost of the necking device. On the other hand, the roller is less likely to press onto parts of the workpiece that do not require necking, reducing unnecessary wear on the workpiece. When the workpiece is a battery cell or its casing, the roller is less likely to press onto parts of the casing that are not locally outwardly expanded, reducing unnecessary wear on the casing. Therefore, when 10 mm ≤ c ≤ 20 mm, the dimension of the roller pressing surface along the extension direction of the roller's rotation axis is more appropriate, allowing for a larger necking range while minimizing the risk of pressing onto parts of the workpiece that do not require necking.

[0034] As an optional technical solution in this application embodiment, the number of the roller pressing components is n, which satisfies: 2≤n≤4.

[0035] In the above technical solution, when n≥2, the number of roller pressing components is relatively large, which can improve the uniformity of force on the workpiece and is beneficial to improving the roller pressing quality. When n≤4, the number of roller pressing components is not excessive, making it easy to arrange the pressure rollers of multiple roller pressing components around the rotation axis of the rotating seat during assembly. Therefore, when 2≤n≤4, both roller pressing quality and assembly convenience can be balanced.

[0036] As an optional technical solution in this application embodiment, the narrowing device includes a first driving mechanism and a second driving mechanism. The first driving mechanism is connected to the rotating seat and the second driving mechanism. The first driving mechanism is configured to drive the rotating seat to rotate, and the second driving mechanism is configured to drive the rotating seat to move along the extension direction of the rotation axis of the rotating seat.

[0037] In the above technical solution, the first driving mechanism drives the rotating seat to rotate, thereby driving multiple roller pressing components to rotate. This allows each roller pressing component's pressure roller to both revolve with the rotating seat and rotate on its own axis, which helps to uniformly shrink the workpiece, improves the shrinking quality, and reduces friction on the workpiece, lowering the risk of scratching. The second driving mechanism drives the first driving mechanism and the rotating seat as a whole to move along the extension direction of the rotating seat's rotation axis, thereby adjusting the distance between the rotating seat and the workpiece. This allows the workpiece to gradually approach the rotating seat, enabling it to gradually contact the roller pressing surface. Under the action of the pressure rollers, the outer contour of the part of the workpiece in contact with the pressure rollers gradually decreases, facilitating a smooth transition between the shrunken and unshrunken parts of the workpiece. The closer the workpiece is to the rotating seat, the greater the degree of shrinking. By adjusting the distance between the workpiece and the rotating seat, the degree of shrinking can be adjusted, adapting to various shrinking requirements.

[0038] As an optional technical solution in this application embodiment, the necking device includes a first dust removal mechanism, which is used to remove dust during the process of the pressure roller pressing the workpiece.

[0039] In the above technical solution, by setting up a first dust removal mechanism to remove dust during the process of pressing the workpiece by the pressure roller, the metal and non-metal particles generated during the pressing process are removed in a timely manner, which helps to reduce the impact of metal and non-metal particles on the pressing, improve the quality of the narrowing, and make the surface cleanliness of the workpiece after pressing higher.

[0040] As an optional technical solution in this application embodiment, the first dust removal mechanism includes a dust removal hood disposed on the rotating seat, the dust removal hood having a dust removal space for inserting the workpiece, and the pressure roller being at least partially located within the dust removal space.

[0041] In the above technical solution, by setting up a dust removal hood, the workpiece can be inserted into the dust removal hood. In this way, the metal and non-metal particles generated during the rolling process can be collected by the dust removal hood and are not easily diffused to other locations. The metal and non-metal particles collected by the dust removal hood can be drawn away by the negative pressure mechanism, thereby realizing dust removal during the rolling process.

[0042] As an optional technical solution in this application embodiment, a window is provided at the position corresponding to the pressure roller of the dust removal hood, and a part of the pressure roller extends into the dust removal space through the window.

[0043] In the above technical solution, by setting a window at the position corresponding to the dust removal hood and the pressure roller, a part of the pressure roller can be inserted into the dust removal hood through the window, which helps to reduce the size of the dust removal hood and facilitates the adjustment of the pressure roller.

[0044] As an optional technical solution in this application embodiment, the necking device further includes a clamping mechanism. Along the extension direction of the rotation axis of the rotating seat, the clamping mechanism is spaced apart from the rotating seat, and the clamping mechanism is used to clamp the workpiece.

[0045] In the above technical solution, by setting a clamping mechanism to clamp the workpiece, it is easier to position the workpiece, reduce the risk of the workpiece running off-center during the rolling process, and help improve the shrinkage quality.

[0046] As an optional technical solution in this application embodiment, the clamping mechanism includes a first clamping member and a second clamping member, the first clamping member and the second clamping member are used to cooperate in clamping the workpiece, and at least one of the first clamping member and the second clamping member is provided with an adsorption member, the adsorption member being used to adsorb the workpiece.

[0047] In the above technical solution, by providing an adsorption element on at least one of the first clamping element and the second clamping element, the adsorption element can adsorb the workpiece and limit the workpiece, further reducing the risk of the workpiece running off-center during the rolling process, which is beneficial to improving the shrinkage quality.

[0048] As an optional technical solution in this application embodiment, the narrowing device further includes a stop member, which is disposed opposite to the rotating seat along the extension direction of the rotation axis of the rotating seat, and is used to stop the end of the workpiece away from the rotating seat.

[0049] In the above technical solution, by setting a stopper to stop the end of the workpiece away from the rotating seat, it is beneficial to reduce the risk of the workpiece shifting during the rolling process and to improve the shrinkage quality.

[0050] As an optional technical solution in this application embodiment, the workpiece is a battery cell, and the battery cell includes electrode terminals; the abutment is provided with a dust removal hole, and the dust removal hole is used to accommodate the electrode terminals.

[0051] In the above technical solution, the abutment is provided with a dust removal hole, which is used to accommodate the electrode terminals. On the one hand, it can avoid the electrode terminals. On the other hand, the dust removal hole can be connected to the negative pressure mechanism to remove dust from the electrode terminals. After the electrode terminals are electrically connected to the tabs of the electrode assembly, the dust removal step of the electrode terminals is integrated into the necking process, which helps to simplify the manufacturing process of the battery cell and reduce the manufacturing cost of the battery cell.

[0052] As an optional technical solution in this application embodiment, the electrode terminal is provided with a liquid injection hole; the abutment includes a docking portion for inserting into the liquid injection hole, a dust removal channel is formed inside the docking portion, at least part of the docking portion extends into the dust removal hole, a receiving cavity is formed between the docking portion and the hole wall of the dust removal hole, the receiving cavity communicates with the dust removal channel, the abutment is provided with an air inlet communicating with the receiving cavity, and the receiving cavity is used to accommodate at least part of the electrode terminal when the docking portion is inserted into the liquid injection hole.

[0053] In the above technical solution, when the mating part of the abutment is inserted into the liquid injection hole of the electrode terminal, the dust removal channel, the receiving cavity and the air inlet are connected, so that air can enter from the air inlet and exhaust from the dust removal channel, thereby realizing gas flow in the dust removal process and improving the dust removal effect. Attached Figure Description

[0054] 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.

[0055] Figure 1 is a schematic diagram of the narrowing device provided in some embodiments of this application;

[0056] Figure 2 is a schematic diagram of the structure of the pressure roller provided in some embodiments of this application;

[0057] Figure 3 is a simplified structural diagram of a workpiece pressed by a pressure roller according to some embodiments of this application;

[0058] Figure 4 is a structural schematic diagram of a necking device provided in some other embodiments of this application;

[0059] Figure 5 is a structural schematic diagram of the pressure roller provided in some other embodiments of this application;

[0060] Figure 6 is a simplified structural schematic diagram of a workpiece pressed by a pressure roller according to some other embodiments of this application;

[0061] Figure 7 is a schematic diagram of a first cross-section of a pressure roller provided in some other embodiments of this application;

[0062] Figure 8 is a structural schematic diagram of a necking device provided in some embodiments of this application;

[0063] Figure 9 is a structural schematic diagram of the pressure roller provided in some embodiments of this application;

[0064] Figure 10 is a simplified structural schematic diagram of a workpiece pressed by a pressure roller according to some embodiments of this application;

[0065] Figure 11 is a schematic diagram of the structure of the pressure roller provided in some embodiments of this application;

[0066] Figure 12 is a schematic block diagram showing the connection between the first drive mechanism, the second drive mechanism, and the rotating seat according to some embodiments of this application;

[0067] Figure 13 is a schematic diagram of the narrowing device provided in some embodiments of this application;

[0068] Figure 14 is a schematic diagram of the structure of the abutment provided in some embodiments of this application;

[0069] Figure 15 is a structural schematic diagram of the abutment provided in some other embodiments of this application;

[0070] Figure 16 is a cross-sectional view of position AA in Figure 15.

[0071] Icons: 10-Narrowing device; 100-Rotating seat; 200-Roller assembly; 210-Pressure roller; 211-Roller surface; 2111-First intersecting line; 212-First roller section; 213-Second roller section; 2131-Abutting surface; 214-Embossing; 220-First adjusting seat; 230-Locking element; 300-First driving mechanism; 400-Second driving mechanism; 510-Dust hood; 511-Window; 600-Clamping mechanism; 610-First clamping element; 620-Second clamping element; 700-Abutting element; 710-Dust removal hole; 711-Receiving cavity; 720-Abutting top; 730-Dating part; 731-Dust removal flow channel; 740-Air inlet; 20-Workpiece; 21-Housing shell; 22-Electrode terminal. Embodiments of the present invention

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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 a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0076] 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.

[0077] 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. 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 and should not constitute any limitation on this application.

[0078] In this application, "multiple" means two or more (including two).

[0079] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0080] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0081] The battery cell includes a casing and an electrode assembly, with the electrode assembly housed within the casing. The casing includes a housing and an end cap, the housing having an opening at one end for accommodating the electrode assembly. The end cap is attached to the housing and closes the opening.

[0082] An end cap is a component that closes onto the opening of the housing to isolate the internal environment of a battery cell from the external environment. The shape of the end cap can be adapted to fit the shape of the housing.

[0083] The housing is a component used to fit with the end cap to form the internal environment of a battery cell. This internal environment can accommodate electrode assemblies, electrolyte, and other components. The housing and end cap can be separate components, with an opening in the housing. The end cap closes the opening to form the internal environment of the battery cell. Alternatively, the end cap and housing can be integrated. Specifically, the end cap and housing can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing, the end cap closes the housing.

[0084] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0085] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0086] The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0087] In related technologies, the casing and end cap of a battery cell are fitted with a gap. During welding, the welding laser can easily penetrate into the casing through the gap between the casing and the end cap, thereby burning the electrode assembly and causing damage to the electrode assembly, resulting in poor reliability of the battery cell.

[0088] To improve the reliability of individual battery cells, research has shown that the casing and end caps can be first fitted with an interference fit, and then welded together. This not only reduces the risk of laser penetration into the casing causing damage to the electrode components, but also improves the welding quality. However, when the casing and end caps are fitted with an interference fit, the casing will locally expand outward under the action of the end caps, resulting in an increase in the volume of the individual battery cell and a lower energy density.

[0089] Therefore, this application provides a necking device for necking a workpiece. The necking device includes a rotating base and multiple roller pressing assemblies, which are arranged around the rotation axis of the rotating base. Each roller pressing assembly includes a rotatable pressure roller, and the pressure rollers of the multiple roller pressing assemblies are configured to cooperate in pressing the workpiece when it approaches the rotating base. The pressure roller has a pressing surface for pressing the workpiece, and the pressing surface intersects with a first cross-section of the pressure roller to form two intersecting lines. The first cross-section passes through the rotation axis of the pressure roller and the rotation axis of the rotating base. The intersecting line closest to the rotation axis of the rotating base is the first intersecting line, and the distance between the first intersecting line and the rotation axis of the rotating base gradually increases along the direction from the rotating base towards the workpiece.

[0090] This necking device comprises a rotating base and multiple roller pressing assemblies. The rotating base can rotate around its own axis, thereby driving the roller pressing assemblies to rotate. Each roller pressing assembly includes a pressure roller that can rotate around its own axis. When pressing the workpiece, the pressure roller not only revolves with the rotating base but also rotates on its own axis, which helps to uniformly neck the workpiece, improves the necking quality, and reduces friction on the workpiece, lowering the risk of scratching it. The distance between the first intersection line and the rotation axis of the rotating base gradually increases along the direction from the rotating base to the workpiece. Thus, as the workpiece approaches the rotating base, it gradually comes into contact with the roller pressing surface. Under the action of the pressure roller, the outer contour of the part of the workpiece in contact with the pressure roller gradually decreases, which helps to smoothly transition the necked part of the workpiece to the unnarrowed part. In addition, the closer the workpiece is to the rotating base, the greater the degree of necking. By adjusting the distance between the workpiece and the rotating base, the degree of necking can be adjusted to meet various necking requirements. When the workpiece is a battery cell or the casing of a battery cell, the necking device can neck the casing, thereby reducing the outer contour of the end of the casing near the opening. This reduces the size of the casing that would otherwise be caused by the interference fit between the end cap and the casing, which helps to reduce the volume of the battery cell and increase its energy density.

[0091] The technical solution described in this application is applicable to the necking process of workpieces, where the workpiece can be a battery cell. Using this necking device to neck the workpiece ensures a smooth transition between the necked and unnecked portions, resulting in better necking quality.

[0092] Please refer to Figures 1, 2, and 3. Figure 1 is a structural schematic diagram of a necking device 10 provided in some embodiments of this application. Figure 2 is a structural schematic diagram of a pressure roller 210 provided in some embodiments of this application. Figure 3 is a simplified structural schematic diagram of a pressure roller 210 pressing a workpiece 20 in some embodiments of this application. This application provides a necking device 10 for necking a workpiece 20. The necking device 10 includes a rotating seat 100 and multiple rolling components 200, which are arranged around the rotation axis of the rotating seat 100. Each rolling component 200 includes a rotatable pressure roller 210, and the pressure rollers 210 of the multiple rolling components 200 are configured to cooperate in pressing the workpiece 20 when it approaches the rotating seat 100. The pressure roller 210 has a pressing surface 211 for pressing the workpiece 20. The pressing surface 211 intersects with the first cross section of the pressure roller 210 to form two intersecting lines. The first cross section passes through the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100. The intersecting line closest to the rotation axis of the rotating seat 100 is the first intersecting line 2111. The distance between the first intersecting line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 to the workpiece 20.

[0093] The rotating base 100 serves as the mounting foundation for multiple roller pressing assemblies 200. The rotating base 100 can rotate around its own axis, driving the multiple roller pressing assemblies 200 to rotate together. The rotating base 100 can be a turntable, a rotating frame, a rotating drum, etc.

[0094] The necking device 10 may include two, three, four, or more roller pressing assemblies 200. The multiple roller pressing assemblies 200 are disposed on the rotating seat 100 around the rotation axis of the rotating seat 100. In some embodiments, the multiple roller pressing assemblies 200 are spaced apart along the circumference of the rotating seat 100. Optionally, the multiple roller pressing assemblies 200 are equally spaced along the circumference of the rotating seat 100, that is, the distance between any two adjacent roller pressing assemblies 200 is equal along the circumference of the rotating seat 100.

[0095] The roller pressing assembly 200 includes a pressure roller 210, which is rotatably mounted on the rotating base 100 around its own axis. When the rotating component rotates, it drives multiple roller pressing assemblies 200 to rotate together. While the pressure roller 210 revolves around the rotation axis of the rotating base 100, it can also rotate around its own axis, thereby pressing the workpiece 20.

[0096] As the workpiece 20 gradually approaches the rotating seat 100, the workpiece 20 gradually comes into contact with the pressure rollers 210 of the multiple roller pressing assemblies 200, and the pressure rollers 210 of the multiple roller pressing assemblies 200 can cooperate to press the workpiece 20.

[0097] The roller surface 211 is the surface of the pressure roller 210 that contacts the workpiece 20 to roll and press it. The roller surface 211 surrounds the outer side of the rotation axis of the pressure roller 210 and is at least a portion of the outer circumferential surface of the pressure roller 210. For example, when the pressure roller 210 is cylindrical, the roller surface 211 can be a cylindrical surface. When the pressure roller 210 is frustum-shaped, the roller surface 211 can be a conical surface. The roller surface 211 can be smooth or rough.

[0098] Please refer to Figure 3. In Figure 3, the rotation axis of the rotating seat 100 and the rotation axis of the pressure roller 210 are represented by dashed lines. The dashed line passing through the workpiece 20 is the rotation axis of the rotating seat 100, and the dashed line passing through the pressure roller 210 is the rotation axis of the pressure roller 210.

[0099] The direction in which the rotating seat 100 points towards the workpiece 20 is parallel to the extension direction of the rotation axis of the rotating seat 100, but the direction in which the rotating seat 100 points towards the workpiece 20 is unidirectional. Please refer to Figure 3, where the direction in which the rotating seat 100 points towards the workpiece 20 is the Y direction shown in the figure.

[0100] The first cross-section is a section passing through the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100. In other words, the rotation axes of the pressure roller 210 and the rotating seat 100 are located within the first cross-section. The roller pressing surface 211 intersects the first cross-section to form two intersecting lines. The intersecting lines can be straight lines or curved lines.

[0101] The first intersection line 2111 is the intersection line that is closest to the rotation axis of the rotating seat 100 among the two intersection lines. Along the direction perpendicular to the rotation axis of the rotating seat 100, the first intersection line 2111 is located between the rotation axis of the rotating seat 100 and the other intersection line.

[0102] The distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 to the workpiece 20. That is, the first intersection line 2111 gradually moves away from the rotation axis of the rotating seat 100 from its end close to the rotating seat 100 to its end far away from the rotating seat 100.

[0103] Referring to Figure 3, the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually decreases along the direction from the workpiece 20 to the rotating seat 100. When the workpiece 20 approaches the rotating seat 100, the workpiece 20 can gradually come into contact with the roller pressing surface 211. Under the action of the pressure roller 210, the outer contour of the part of the workpiece 20 that comes into contact with the pressure roller 210 gradually decreases, which helps to make the constricted part of the workpiece 20 and the unconstricted part of the workpiece 20 transition smoothly.

[0104] The necking device 10 is equipped with a rotating base 100 and multiple roller pressing assemblies 200. The rotating base 100 can rotate around its own axis, thereby driving the multiple roller pressing assemblies 200 to rotate. Each roller pressing assembly 200 includes a pressure roller 210 that can rotate around its own axis. When pressing the workpiece 20, the pressure roller 210 can not only follow the rotating base 100 in revolution but also rotate on its own axis. This is beneficial for uniformly necking the workpiece 20, improving the necking quality, and also for reducing the frictional force on the workpiece 20, thus reducing the risk of scratching the workpiece 20. The distance between the first intersection line 2111 and the rotation axis of the rotating base 100 gradually increases along the direction from the rotating base 100 to the workpiece 20. In this way, when the workpiece 20 approaches the rotating base 100, the workpiece 20 can gradually come into contact with the roller pressing surface 211. Under the action of the pressure roller 210, the outer contour of the part of the workpiece 20 in contact with the pressure roller 210 gradually decreases, which is beneficial for a smooth transition between the necked part and the unnarrowed part of the workpiece 20. Furthermore, the closer the workpiece 20 is to the rotating seat 100, the greater the degree of narrowing of the workpiece 20. By adjusting the distance between the workpiece 20 and the rotating seat 100, the degree of narrowing of the workpiece 20 can be adjusted to meet various narrowing requirements. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, the narrowing device 10 can narrow the housing 21, reducing the outer contour of the end of the housing 21 near the opening. This reduces the size of the local outward expansion of the housing 21 caused by the interference fit between the end cap and the housing 21, which is beneficial for reducing the volume of the battery cell and increasing the energy density of the battery cell.

[0105] Referring to Figures 1, 2, and 3, in some embodiments, the roller pressing assembly 200 includes a first adjusting seat 220 and a locking member 230. The first adjusting seat 220 is rotatably disposed on the rotating seat 100, and the pressure roller 210 is rotatably disposed on the first adjusting seat 220 about its own axis. The rotation axis of the first adjusting seat 220 intersects the rotation axis of the rotating seat 100, and the rotation axis of the first adjusting seat 220 intersects the rotation axis of the pressure roller 210. The locking member 230 is used to unlockably lock the first adjusting seat 220 and the rotating seat 100.

[0106] The angle between the rotation axis of the first adjusting seat 220 and the rotation axis of the rotating seat 100 can be an acute angle or a right angle. The angle between the rotation axis of the first adjusting seat 220 and the rotation axis of the pressure roller 210 can also be an acute angle or a right angle. Referring to Figure 1, in the embodiment shown in Figure 1, the rotation axis of the first adjusting seat 220 is perpendicular to the rotation axis of the rotating seat 100, and the rotation axis of the first adjusting seat 220 is perpendicular to the rotation axis of the pressure roller 210.

[0107] The locking member 230 has an unlocked state and a locked state. When the locking member 230 is in the unlocked state, it unlocks the first adjusting seat 220 and the rotating seat 100, allowing the first adjusting seat 220 to rotate relative to the rotating seat 100, thus facilitating the adjustment of the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100. When the locking member 230 is in the locked state, it locks the first adjusting seat 220 and the rotating seat 100, preventing the first adjusting seat 220 from rotating relative to the rotating seat 100, thus facilitating the pressure roller 210 to press the workpiece 20.

[0108] Optionally, the rotating seat 100 is provided with a mounting block, which includes a first arm, a second arm, and a connecting part. The first arm and the second arm are arranged opposite to each other, and the connecting part connects the first arm and the second arm and is fixed to the rotating seat 100. The locking member 230 includes a bolt and a nut. The bolt passes through the first arm and the second arm, and the first adjusting seat 220 is disposed between the first arm and the second arm and sleeved on the outside of the bolt's thread. When the bolt and nut are tightened, the first arm and the second arm clamp the first adjusting seat 220, preventing the first adjusting seat 220 from rotating relative to the rotating seat 100. At this time, the locking member 230 is in a locked state. When the bolt and nut are loosened, the first arm and the second arm no longer clamp the first adjusting seat 220, allowing the first adjusting seat 220 to rotate relative to the rotating seat 100. At this time, the locking member 230 is in an unlocked state.

[0109] By setting the first adjusting seat 220 and the locking element 230, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 can be adjusted as needed to meet more shrinking requirements and improve the adaptability of the shrinking device 10 to different shrinking requirements.

[0110] Referring to Figures 1, 2, and 3, in some embodiments, the roller surface 211 is a cylindrical surface, and the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is an acute angle.

[0111] When the roller pressing surface 211 is a cylindrical surface, the pressure roller 210 can be cylindrical, and the outer circumferential surface of the pressure roller 210 is the roller pressing surface 211.

[0112] The angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is greater than 0 and less than 90°.

[0113] When the roller pressing surface 211 is a cylindrical surface, in order to make the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increase along the direction from the rotating seat 100 to the workpiece 20, the pressure roller 210 can be arranged at an angle, that is, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is an acute angle. In addition, when the roller pressing surface 211 is a cylindrical surface, the increase in the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 along the direction from the rotating seat 100 to the workpiece 20 is uniform, so that the degree of narrowing of the workpiece 20 changes uniformly as it approaches the rotating seat 100, thereby facilitating the control of the narrowing quality and degree, and helping to increase the smoothness of the narrowing position of the workpiece 20.

[0114] Please refer to Figures 1, 2 and 3. In some embodiments, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is α, which satisfies: 0 < α ≤ 30°.

[0115] 'a' represents the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100.

[0116] The angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 can be: a=0.5°, 1°, 5°, 10°, 15°, 20°, 25°, 30°, etc.

[0117] When a > 0, and the roller pressing surface 211 is cylindrical, the pressure roller 210 is inclined, causing the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 to gradually increase along the direction from the rotating seat 100 towards the workpiece 20, thereby facilitating the roller pressing of the workpiece 20. Furthermore, it reduces the risk of leaving indentations on the workpiece 20. When a ≤ 30°, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is small, which helps to ensure a smooth transition between the constricted portion and the unconstricted portion of the workpiece 20. Therefore, when 0 < a ≤ 30°, the roller pressing quality can be improved, the risk of leaving indentations on the workpiece 20 can be reduced, and the transition between the constricted portion and the unconstricted portion of the workpiece 20 can be made smooth.

[0118] Optionally, 1°≤a≤8°.

[0119] The angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 can be: a = 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, etc.

[0120] When a > 1°, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is relatively large, which can further reduce the risk of leaving indentations on the workpiece 20. When a ≤ 8°, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is not too large, which helps to make the transition between the constricted portion and the unconstricted portion of the workpiece 20 smoother. Therefore, when 1° ≤ a ≤ 8°, the rolling quality can be improved, the risk of leaving indentations on the workpiece 20 can be further reduced, and the transition between the constricted portion and the unconstricted portion of the workpiece 20 can be smoother.

[0121] Please refer to Figures 4, 5, and 6. Figure 4 is a structural schematic diagram of the necking device 10 provided in some embodiments of this application. Figure 5 is a structural schematic diagram of the pressure roller 210 provided in some embodiments of this application. Figure 6 is a simplified structural schematic diagram of the pressure roller 210 pressing the workpiece 20 in some embodiments of this application. In some embodiments, the pressing surface 211 is a conical surface, and the rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100.

[0122] When the roller pressing surface 211 is a conical surface, the pressure roller 210 can be in the shape of a frustum or a cone, and the outer circumferential surface of the pressure roller 210 is the roller pressing surface 211.

[0123] When the roller pressing surface 211 is a conical surface, simply making the rotation axis of the pressure roller 210 parallel to the rotation axis of the rotating seat 100 will allow the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 to gradually increase along the direction from the rotating seat 100 towards the workpiece 20. Furthermore, when the roller pressing surface 211 is a conical surface and the rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100, the increase in the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 along the direction from the rotating seat 100 towards the workpiece 20 is uniform. This ensures that the degree of narrowing of the workpiece 20 changes uniformly as it approaches the rotating seat 100, facilitating control over the quality and degree of narrowing and increasing the smoothness of the narrowing position of the workpiece 20.

[0124] In some embodiments, the pressure roller 210 is detachably connected to the rotating seat 100.

[0125] "Detachable connection" refers to a connection method in which the connecting parts and the connected parts remain undamaged and maintain the original connection quality even after repeated assembly and disassembly. For example, the pressure roller 210 can be keyed to the rotating seat 100, and the pressure roller 210 can also be pinned to the rotating seat 100.

[0126] By detachably connecting the pressure roller 210 to the rotating seat 100, more necking requirements can be met by replacing the pressure roller 210 with different tapers, which helps to improve the adaptability of the necking device 10 to different necking requirements.

[0127] Please refer to Figures 4, 5, 6, and 7. Figure 7 is a schematic diagram of the first cross-section of the pressure roller 210 provided in some other embodiments of this application. In some embodiments, the angle between the first intersecting line 2111 and the rotation axis of the rotating seat 100 is b, satisfying: 0 < b ≤ 30°.

[0128] When the roller pressing surface 211 is a conical surface, the first intersection line 2111 is a straight line segment.

[0129] b represents the angle between the first intersection line 2111 and the rotation axis of the rotating seat 100.

[0130] The angle between the first intersecting line 2111 and the rotation axis of the rotating seat 100 can be: b=0.5°, 1°, 5°, 10°, 15°, 20°, 25°, 30°, etc.

[0131] When b > 0, the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 to the workpiece 20, thereby facilitating the rolling of the workpiece 20. Furthermore, it reduces the risk of leaving indentations on the workpiece 20. When b ≤ 30°, the angle between the first intersection line 2111 and the rotation axis of the rotating seat 100 is small, which helps to ensure a smooth transition between the constricted portion and the unconstricted portion of the workpiece 20. Therefore, when 0 < b ≤ 30°, the rolling quality can be improved, the risk of leaving indentations on the workpiece 20 can be reduced, and the transition between the constricted portion and the unconstricted portion of the workpiece 20 can be made smooth.

[0132] Optionally, 1 ≤ b ≤ 8°.

[0133] The angle between the first intersection line 2111 and the rotation axis of the rotating seat 100 can be: b = 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, etc.

[0134] When b > 1°, the angle between the first intersection line 2111 and the rotation axis of the rotating seat 100 is relatively large, which can further reduce the risk of leaving indentations on the workpiece 20. When b ≤ 8°, the angle between the first intersection line 2111 and the rotation axis of the rotating seat 100 is not too large, which helps to make the transition between the constricted portion and the unconstricted portion of the workpiece 20 smoother. Therefore, when 1 ≤ b ≤ 8°, the rolling quality can be improved, the risk of leaving indentations on the workpiece 20 can be further reduced, and the transition between the constricted portion and the unconstricted portion of the workpiece 20 can be smoother.

[0135] Please refer to Figures 8, 9, and 10. Figure 8 is a structural schematic diagram of the necking device 10 provided in some embodiments of this application. Figure 9 is a structural schematic diagram of the pressure roller 210 provided in some embodiments of this application. Figure 10 is a simplified structural schematic diagram of the pressure roller 210 pressing the workpiece 20 in some embodiments of this application. In some embodiments, the pressure roller 210 includes a first pressing portion 212 and a second pressing portion 213, wherein the minimum diameter of the second pressing portion 213 is greater than the maximum diameter of the first pressing portion 212. The outer peripheral surface of the first pressing portion 212 is a pressing surface 211. The outer peripheral surfaces of the first pressing portion 212 and the second pressing portion 213 are connected by an abutment surface 2131, which is used to abut against one end of the workpiece 20 near the rotating seat 100.

[0136] The first roller pressing section 212 is the portion of the pressure roller 210 used to press the outer peripheral surface of the workpiece 20, and the outer peripheral surface of the first roller pressing section 212 is the pressing surface 211. The second roller pressing section 213 is the portion of the pressure roller 210 used to abut against the end of the workpiece 20 facing the rotating seat 100. The first roller pressing section 212 is connected to one end of the second roller pressing section 213.

[0137] The minimum diameter of the second roller pressing section 213 is greater than the maximum diameter of the first roller pressing section 212. Referring to Figures 8, 9 and 10, in the embodiment shown in the figures, the first roller pressing section 212 is frustum-shaped, the second roller pressing section 213 is cylindrical, and the diameter of the large end of the first roller pressing section 212 is smaller than the diameter of the second roller pressing section 213.

[0138] The abutment surface 2131 is the surface that connects the outer peripheral surface of the first roller pressing part 212 and the outer peripheral surface of the second roller pressing part 213. Referring to Figures 8, 9 and 10, in the embodiment shown in the figures, the abutment surface 2131 is the end face of the second roller pressing part 213 facing the first roller pressing part 212. The abutment surface 2131 can abut against the end of the workpiece 20 near the rotating seat 100, thereby limiting the workpiece 20.

[0139] When rolling workpiece 20, the rolling surface 211 can contact the outer peripheral surface of workpiece 20, and the abutment surface 2131 can abut the end of workpiece 20 near the rotating seat 100. This can improve the tensile stress distribution of workpiece 20 during the rolling process, so that workpiece 20 still has high strength after rolling. When workpiece 20 is a battery cell, the rolling surface 211 can roll the outer peripheral surface of the housing 21, and the abutment surface 2131 can abut against the end cap. This can, to a certain extent, offset the tensile stress of the weld seam generated by the rolling process on the housing 21 and the end cap, so that the housing 21 and the end cap have high connection strength.

[0140] Referring to Figures 8, 9, and 10, in some embodiments, the first roller pressing part 212 is frustum-shaped, and the second roller pressing part 213 is cylindrical. The end face of the second roller pressing part 213 facing the first roller pressing part 212 is the abutment surface 2131. The rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100.

[0141] The first roller pressing section 212 is frustum-shaped, and the pressing surface 211 is a conical surface. By simply aligning the rotation axis of the pressure roller 210 with the rotation axis of the rotating seat 100, the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 towards the workpiece 20. The second roller pressing section 213 is cylindrical, resulting in a larger contact surface 2131. This increases the contact area with the workpiece 20, improves the tensile stress distribution on the workpiece 20 during the rolling process, and ensures that the workpiece 20 retains high strength after rolling.

[0142] Please refer to Figure 11, which is a structural schematic diagram of the pressure roller 210 provided in some embodiments of this application. In some embodiments, embossing 214 is provided on the roller pressing surface 211.

[0143] Embossing 214, also known as knurling or roll forming, refers to the embossing 214 provided on the roll-pressed surface 211, meaning that the roll-pressed surface 211 has uniform raised and recessed textures. Referring to Figure 11, in the embodiment shown in Figure 11, the embossing 214 is a mesh pattern. In other embodiments, the embossing 214 can also be horizontal or vertical lines.

[0144] By setting embossing 214 on the roller pressing surface 211, the part of the workpiece 20 that contacts the pressure roller 210 is uniformly roughened, which facilitates the subsequent rust prevention treatment of the workpiece 20.

[0145] Referring to Figures 3, 6, 7 and 10, in some embodiments, the size of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is c, where 5mm ≤ c ≤ 30mm.

[0146] The direction of extension of the rotation axis of the pressure roller 210 is also the axial direction of the pressure roller 210. Please refer to Figures 3, 6, 7 and 10. The direction of extension of the rotation axis of the pressure roller 210 is the X direction shown in the figures.

[0147] c represents the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210. When the pressure roller 210 is cylindrical or frustum-shaped, the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is equal to the length of the pressure roller 210 along its axial direction.

[0148] The dimensions of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 can be: c=5mm, 10mm, 15mm, 20mm, 25mm, 30mm, etc.

[0149] When c ≥ 5 mm, the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is relatively large, resulting in a larger narrowing range and adaptability to various narrowing requirements. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, it can reduce the size of the housing 21 that would be partially expanded due to the interference fit between the end cap and the housing 21. When c ≤ 30 mm, the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is not too large. On the one hand, this reduces the manufacturing cost of the pressure roller 210 and the cost of the narrowing device 10. On the other hand, the pressure roller 210 is less likely to press on the parts of the workpiece 20 that do not require narrowing treatment, thus reducing unnecessary wear on the workpiece 20. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, the pressure roller 210 is less likely to press on the parts of the housing 21 that are not partially expanded, thus reducing unnecessary wear on the housing 21. Therefore, when 5mm≤c≤30mm, the size of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is moderate, which can make the narrowing range larger, and it is not easy to roll the part of the workpiece 20 that does not need to be narrowed.

[0150] Optionally, 10mm ≤ c ≤ 20mm.

[0151] The dimensions of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 can be: c=10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc.

[0152] When c ≥ 10 mm, the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is larger, resulting in a larger necking range and adaptability to more necking requirements. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, it can reduce the size of the local outward expansion of the housing 21 caused by the interference fit between the end cap and the housing 21. When c ≤ 20 mm, the dimension of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is not too large. On the one hand, it can further reduce the manufacturing cost of the pressure roller 210 and the cost of the necking device 10. On the other hand, the pressure roller 210 is less likely to press the part of the workpiece 20 that does not require necking, thus reducing unnecessary wear on the workpiece 20. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, the pressure roller 210 is less likely to press the part of the housing 21 that is not locally outwardly expanded, thus reducing unnecessary wear on the housing 21. Therefore, when 10mm≤c≤20mm, the size of the roller pressing surface 211 along the extension direction of the rotation axis of the pressure roller 210 is more appropriate, which can make the narrowing range larger and make it less likely to roll the part of the workpiece 20 that does not need to be narrowed.

[0153] In some embodiments, the number of roller pressing assemblies 200 is n, satisfying: 2≤n≤4.

[0154] The number of roller pressing components 200 can be 2, 3 or 4.

[0155] When n≥2, the number of roller pressing assemblies 200 is relatively large, which can improve the uniformity of force on the workpiece 20 and is beneficial to improving the quality of roller pressing. When n≤4, the number of roller pressing assemblies 200 is not excessive, making it easy to arrange the pressure rollers 210 of multiple roller pressing assemblies 200 around the rotation axis of the rotating seat 100 during assembly. Therefore, when 2≤n≤4, both the quality of roller pressing and the convenience of assembly can be balanced.

[0156] Please refer to Figure 12, which is a schematic block diagram showing the connection between a first driving mechanism 300, a second driving mechanism 400, and a rotating seat 100 according to some embodiments of this application. In some embodiments, the narrowing device 10 includes a first driving mechanism 300 and a second driving mechanism 400, with the first driving mechanism 300 connected to the rotating seat 100 and the second driving mechanism 400. The first driving mechanism 300 is configured to drive the rotating seat 100 to rotate, and the second driving mechanism 400 is configured to drive the rotating seat 100 to move along the extension direction of the rotation axis of the rotating seat 100.

[0157] A first drive mechanism 300 is connected to the rotating base 100 and is used to drive the rotating base 100 to rotate. The first drive mechanism 300 may include a first rotary drive member connected to the rotating base 100, thereby driving the rotating base 100 to rotate. The first rotary drive member may be an electrode, an internal combustion engine, etc. The first drive mechanism 300 may also include a first linear drive member and a first transmission mechanism. The first transmission mechanism connects the first linear drive member and the rotating base 100. The first linear drive member outputs linear motion, and the first transmission mechanism converts the linear motion output by the first linear drive member into the rotational motion of the rotating base 100. The first linear drive member may be a linear electric cylinder, a linear hydraulic cylinder, a linear pneumatic cylinder, etc. The first transmission mechanism may be a crank-slider mechanism, a ball screw mechanism, etc.

[0158] The second drive mechanism 400 is connected to the first drive mechanism 300. The second drive mechanism 400 drives the first drive mechanism 300 and the rotating seat 100 as a whole to move along the extension direction of the rotation axis of the rotating seat 100. The second drive mechanism 400 may include a second linear drive member connected to the first drive mechanism 300. The second linear drive member outputs linear motion, thereby driving the first drive mechanism 300 and the rotating seat 100 as a whole to move. The second linear drive member can be a linear electric cylinder, a linear hydraulic cylinder, a linear pneumatic cylinder, etc. The second drive mechanism 400 may also include a second rotary drive member and a second transmission mechanism. The second transmission mechanism connects the second rotary drive member and the first drive mechanism 300. The second rotary drive member outputs rotational motion, and the second transmission mechanism converts the rotational motion output by the second rotary drive member into linear motion of the first drive mechanism 300. The second rotary drive member can be an electric motor, an internal combustion engine, etc. The second transmission mechanism can be a crank-slider mechanism, a ball screw mechanism, etc.

[0159] The first drive mechanism 300 drives the rotating seat 100 to rotate, thereby driving multiple roller pressing components 200 to rotate. This allows the pressure rollers 210 of each roller pressing component 200 to both revolve around the rotating seat 100 and rotate on their own axis. This facilitates uniform necking of the workpiece 20, improves necking quality, and reduces friction on the workpiece 20, lowering the risk of scratching it. The second drive mechanism 400 drives the first drive mechanism 300 and the rotating seat 100 together to move along the extension direction of the rotating axis of the rotating seat 100. This adjusts the distance between the rotating seat 100 and the workpiece 20, allowing the workpiece 20 to gradually approach the rotating seat 100 and gradually contact the roller pressing surface 211. Under the action of the pressure rollers 210, the outer contour of the part of the workpiece 20 in contact with the pressure rollers 210 gradually decreases, which helps to smoothly transition the necked portion of the workpiece 20 with the unnecked portion. The closer the workpiece 20 is to the rotating seat 100, the greater the degree of narrowing of the workpiece 20. By adjusting the distance between the workpiece 20 and the rotating seat 100, the degree of narrowing of the workpiece 20 can be adjusted, which can meet various narrowing requirements.

[0160] Please refer to Figure 13, which is a schematic diagram of the structure of the necking device 10 provided in some embodiments of this application. In some embodiments, the necking device 10 includes a first dust removal mechanism, which is used to remove dust during the process of the pressure roller 210 pressing the workpiece 20.

[0161] The first dust removal mechanism is used to remove dust during the process of the pressure roller 210 pressing the workpiece 20. The first dust removal mechanism can be a negative pressure dust removal mechanism, an electrostatic dust removal mechanism, etc.

[0162] By setting up a first dust removal mechanism to remove dust during the process of pressing the workpiece 20 by the pressure roller 210, metal and non-metal particles generated during the pressing process are removed in a timely manner. This helps to reduce the impact of metal and non-metal particles on the pressing process, improve the quality of the narrowing, and make the surface cleanliness of the workpiece 20 after pressing higher.

[0163] Referring to Figure 13, in some embodiments, the first dust removal mechanism includes a dust removal hood 510 disposed on the rotating seat 100, the dust removal hood 510 having a dust removal space for inserting the workpiece 20, and the pressure roller 210 being at least partially located within the dust removal space.

[0164] The dust collector hood 510 is used to cover the constricted end of the workpiece 20 when the pressure roller 210 presses the workpiece 20, in order to collect the metal and non-metal particles generated during the pressing process. The dust collector hood 510 has a dust collection space, into which the constricted end of the workpiece 20 can extend. The pressure roller 210 may be partially located within the dust collection space and partially located outside the dust collection space, or the pressure roller 210 may be completely located within the dust collection space.

[0165] By setting up a dust removal hood 510, the workpiece 20 can be inserted into the dust removal hood 510. In this way, the metal and non-metal particles generated during the rolling process can be collected by the dust removal hood 510 and are not easily diffused to other locations. The metal and non-metal particles collected by the dust removal hood 510 can be drawn away by the negative pressure mechanism, thereby achieving dust removal during the rolling process.

[0166] Referring to Figure 13, in some embodiments, a window 511 is provided at the position corresponding to the pressure roller 210 of the dust removal hood 510, and a part of the pressure roller 210 extends into the dust removal space through the window 511.

[0167] A window 511 is provided at the position corresponding to the dust removal hood 510 and the pressure roller 210. The window 511 connects the dust removal space and the outside. A part of the pressure roller 210 extends into the dust removal space through the window 511.

[0168] By setting a window 511 at the position corresponding to the pressure roller 210 in the dust removal hood 510, a part of the pressure roller 210 can be inserted into the dust removal hood 510 through the window 511, which helps to reduce the size of the dust removal hood 510 and facilitates the adjustment of the pressure roller 210.

[0169] Referring to Figure 13, in some embodiments, the narrowing device 10 further includes a clamping mechanism 600. Along the extension direction of the rotation axis of the rotating seat 100, the clamping mechanism 600 is spaced apart from the rotating seat 100, and the clamping mechanism 600 is used to clamp the workpiece 20.

[0170] The clamping mechanism 600 is a structure used to clamp the workpiece 20. The clamping mechanism 600 is disposed opposite to the rotating seat 100 along the extension direction of the rotation axis of the rotating seat 100, and there is a gap between them.

[0171] By setting up a clamping mechanism 600 to clamp the workpiece 20, it is easier to position the workpiece 20, reduce the risk of the workpiece 20 running off-center during the rolling process, and help improve the shrinkage quality.

[0172] Referring to Figure 13, in some embodiments, the clamping mechanism 600 includes a first clamping member 610 and a second clamping member 620, which are used to clamp the workpiece 20. At least one of the first clamping member 610 and the second clamping member 620 is provided with an adsorption member for adsorbing the workpiece 20.

[0173] The first clamping member 610 and the second clamping member 620 can cooperate to clamp the workpiece 20, thereby limiting the position of the workpiece 20. Optionally, the first clamping member 610 supports the workpiece 20 along the direction of gravity, and the second clamping member 620 presses the workpiece 20 downward from above the first clamping member 610.

[0174] An adsorption element is a component used to adsorb and position the workpiece 20. In some embodiments, the adsorption element includes a magnet, which adsorbs the workpiece 20 by magnetic attraction. In other embodiments, the adsorption element includes a negative pressure mechanism, which adsorbs the workpiece 20 by drawing a negative pressure.

[0175] The suction element can be provided only on the first clamping member 610 and not on the second clamping member 620, or the suction element can be provided only on the second clamping member 620 and not on the first clamping member 610, or the suction element can be provided on both the first clamping member 610 and the second clamping member 620.

[0176] By providing an adsorption element on at least one of the first clamping member 610 and the second clamping member 620, the adsorption element can adsorb the workpiece 20 and limit the workpiece 20, further reducing the risk of the workpiece 20 running off-center during the rolling process, which is beneficial to improving the shrinkage quality.

[0177] Referring to Figure 13, in some embodiments, the narrowing device 10 further includes a stop member 700. Along the extension direction of the rotation axis of the rotating seat 100, the stop member 700 is disposed opposite to the rotating seat 100, and the stop member 700 is used to stop the end of the workpiece 20 away from the rotating seat 100.

[0178] The abutment 700 is a component used to abut the end of the workpiece 20 away from the rotating seat 100. Along the extension direction of the rotation axis of the rotating seat 100, the abutment 700 is opposite to the rotating seat 100 and spaced apart.

[0179] By setting the abutment 700 to abut the end of the workpiece 20 away from the rotating seat 100, it is beneficial to reduce the risk of the workpiece 20 moving around during the rolling process and to improve the shrinkage quality.

[0180] Please refer to Figures 13 and 14. Figure 14 is a schematic diagram of the structure of the abutment 700 provided in some embodiments of this application. In some embodiments, the workpiece 20 is a battery cell, and the battery cell includes electrode terminals 22. The abutment 700 is provided with a dust removal hole 710 for accommodating the electrode terminals 22.

[0181] Electrode terminal 22 is used for electrical connection with the tab of the electrode assembly to input or output electrical energy from the battery cell. Electrode terminal 22 and the tab can be directly connected, for example, by direct soldering. Electrode terminal 22 and the tab can also be indirectly connected, for example, by connecting them indirectly through a current collector.

[0182] The dust removal hole 710 is a through hole provided in the abutment member 700, extending through the abutment member 700 along the rotation axis of the rotating seat 100. When the abutment member 700 abuts against the end of the battery cell away from the rotating seat 100, the electrode terminal 22 is accommodated in the dust removal hole 710. The dust removal hole 710 can communicate with a negative pressure mechanism to remove dust from the electrode terminal 22.

[0183] The abutment 700 is provided with a dust removal hole 710, which is used to accommodate the electrode terminal 22. On the one hand, it can avoid the electrode terminal 22. On the other hand, the dust removal hole 710 can be connected to the negative pressure mechanism to remove dust from the electrode terminal 22. After the electrode terminal 22 is electrically connected to the tab of the electrode assembly, the dust removal step of the electrode terminal 22 is integrated into the necking process, which helps to simplify the manufacturing process of the battery cell and reduce the manufacturing cost of the battery cell.

[0184] Please refer to Figures 15 and 16. Figure 15 is a structural schematic diagram of the abutment 700 provided in some embodiments of this application. Figure 16 is a cross-sectional view at position AA in Figure 15. In some embodiments, the electrode terminal 22 is provided with an injection hole. The abutment 700 includes a mating portion 730 for insertion into the injection hole. A dust removal channel 731 is formed inside the mating portion 730. The mating portion 730 extends at least partially into the dust removal hole 710. A receiving cavity 711 is formed between the mating portion 730 and the hole wall of the dust removal hole 710, and the receiving cavity 711 communicates with the dust removal channel 731. The abutment 700 is provided with an air inlet 740 communicating with the receiving cavity 711. The receiving cavity 711 is used to receive at least a portion of the electrode terminal 22 when the mating portion 730 is inserted into the injection hole.

[0185] Electrode terminal 22 is provided with a liquid injection hole, through which electrolyte is injected into the battery cell.

[0186] The abutment member 700 includes an abutment top 720 and a mating portion 730. The mating portion 730 is connected to the abutment top 720. The abutment top 720 is used to abut the end of the battery cell away from the rotating seat 100, and the mating portion 730 is used to insert into the liquid injection hole of the electrode terminal 22. A dust removal hole 710 is provided in the abutment top 720. At least a portion of the mating portion 730 extends into the dust removal hole 710, and a receiving cavity 711 for accommodating the electrode terminal 22 is formed between the mating portion 730 and the hole wall of the dust removal hole 710. It should be noted that when the electrode terminal 22 is accommodated in the receiving cavity 711, a fluid channel is still maintained between the electrode terminal 22 and the mating portion 730. A dust removal flow channel 731 is formed inside the mating portion 730, and an air inlet 740 is provided on the abutment member 700. The fluid channel connects the air inlet 740 and the dust removal flow channel 731.

[0187] The narrowing device 10 includes a second dust removal mechanism. The air inlet of the second dust removal mechanism is connected to the air inlet 740, and the exhaust end of the second dust removal mechanism is connected to the dust removal channel 731, thereby realizing gas flow during the dust removal process.

[0188] When the mating part 730 of the abutment member 700 is inserted into the liquid injection hole of the electrode terminal 22, the dust removal channel 731, the receiving cavity 711 and the air inlet 740 are connected, and air can be introduced from the air inlet 740 and exhausted from the dust removal channel 731, so as to realize the gas flow in the dust removal process and improve the dust removal effect.

[0189] Please refer to Figures 1 to 16 for some embodiments of this application.

[0190] This application provides a necking device 10 for necking a workpiece 20. The necking device 10 includes a rotating base 100 and multiple roller pressing assemblies 200, which are arranged around the rotation axis of the rotating base 100. Each roller pressing assembly 200 includes a rotatable pressure roller 210. The pressure rollers 210 of the multiple roller pressing assemblies 200 are configured to cooperate in pressing the workpiece 20 when it approaches the rotating base 100. The pressure roller 210 has a pressing surface 211 for pressing the workpiece 20. The pressing surface 211 intersects a first cross-section of the pressure roller 210 to form two intersecting lines. The first cross-section passes through the rotation axis of the pressure roller 210 and the rotation axis of the rotating base 100. The intersecting line closest to the rotation axis of the rotating base 100 is the first intersecting line 2111. The distance between the first intersecting line 2111 and the rotation axis of the rotating base 100 gradually increases along the direction from the rotating base 100 towards the workpiece 20. The necking device 10 is equipped with a rotating base 100 and multiple roller pressing assemblies 200. The rotating base 100 can rotate around its own axis, thereby driving the multiple roller pressing assemblies 200 to rotate. Each roller pressing assembly 200 includes a pressure roller 210 that can rotate around its own axis. When pressing the workpiece 20, the pressure roller 210 can not only follow the rotating base 100 in revolution but also rotate on its own axis. This is beneficial for uniformly necking the workpiece 20, improving the necking quality, and also for reducing the frictional force on the workpiece 20, thus reducing the risk of scratching the workpiece 20. The distance between the first intersection line 2111 and the rotation axis of the rotating base 100 gradually increases along the direction from the rotating base 100 to the workpiece 20. In this way, when the workpiece 20 approaches the rotating base 100, the workpiece 20 can gradually come into contact with the roller pressing surface 211. Under the action of the pressure roller 210, the outer contour of the part of the workpiece 20 in contact with the pressure roller 210 gradually decreases, which is beneficial for a smooth transition between the necked part and the unnarrowed part of the workpiece 20. Furthermore, the closer the workpiece 20 is to the rotating seat 100, the greater the degree of narrowing of the workpiece 20. By adjusting the distance between the workpiece 20 and the rotating seat 100, the degree of narrowing of the workpiece 20 can be adjusted to meet various narrowing requirements. When the workpiece 20 is a battery cell or the housing 21 of a battery cell, the narrowing device 10 can narrow the housing 21, reducing the outer contour of the end of the housing 21 near the opening. This reduces the size of the local outward expansion of the housing 21 caused by the interference fit between the end cap and the housing 21, which is beneficial for reducing the volume of the battery cell and increasing the energy density of the battery cell.

[0191] The roller pressing assembly 200 includes a first adjusting seat 220 and a locking member 230. The first adjusting seat 220 is rotatably disposed on a rotating seat 100, and the pressure roller 210 is rotatably disposed on the first adjusting seat 220 about its own axis. The rotation axis of the first adjusting seat 220 intersects the rotation axis of the rotating seat 100, and the rotation axis of the first adjusting seat 220 intersects the rotation axis of the pressure roller 210. The locking member 230 is used to unlockably lock the first adjusting seat 220 and the rotating seat 100. The locking member 230 has an unlocked state and a locked state. When the locking member 230 is in the unlocked state, the locking member 230 unlocks the first adjusting seat 220 and the rotating seat 100, and the first adjusting seat 220 can rotate relative to the rotating seat 100, thereby facilitating the adjustment of the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100. When the locking element 230 is in the locked state, it locks the first adjusting seat 220 and the rotating seat 100, preventing the first adjusting seat 220 from rotating relative to the rotating seat 100, thus facilitating the pressure roller 210 to press the workpiece 20. By setting the first adjusting seat 220 and the locking element 230, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 can be adjusted as needed, meeting more necking requirements and improving the adaptability of the necking device 10 to different necking needs.

[0192] In some embodiments, the roller pressing surface 211 is a cylindrical surface, and the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is an acute angle. When the roller pressing surface 211 is a cylindrical surface, the pressure roller 210 can be cylindrical. In order to make the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increase along the direction from the rotating seat 100 to the workpiece 20, the pressure roller 210 can be arranged at an angle, that is, the angle between the rotation axis of the pressure roller 210 and the rotation axis of the rotating seat 100 is an acute angle. In addition, when the roller pressing surface 211 is a cylindrical surface, the increase in the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 along the direction from the rotating seat 100 to the workpiece 20 is uniform, so that the degree of narrowing of the workpiece 20 changes uniformly as it approaches the rotating seat 100, thereby facilitating the control of the narrowing quality and degree, and helping to increase the smoothness of the narrowing position of the workpiece 20.

[0193] In other embodiments, the roller pressing surface 211 is a conical surface, and the rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100. When the roller pressing surface 211 is a conical surface, it is only necessary to make the rotation axis of the pressure roller 210 parallel to the rotation axis of the rotating seat 100, so that the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 to the workpiece 20. In addition, when the roller pressing surface 211 is a conical surface and the rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100, the increase in the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 along the direction from the rotating seat 100 to the workpiece 20 is uniform, so that the degree of narrowing of the workpiece 20 changes uniformly as it approaches the rotating seat 100, thereby facilitating the control of the narrowing quality and degree, and helping to increase the smoothness of the narrowing position of the workpiece 20.

[0194] In some embodiments, the pressure roller 210 includes a first pressing portion 212 and a second pressing portion 213. The minimum diameter of the second pressing portion 213 is larger than the maximum diameter of the first pressing portion 212. The outer peripheral surface of the first pressing portion 212 is a pressing surface 211. The outer peripheral surfaces of the first pressing portion 212 and the second pressing portion 213 are connected by an abutment surface 2131, which abuts against the end of the workpiece 20 near the rotating seat 100. When pressing the workpiece 20, the pressing surface 211 can contact the outer peripheral surface of the workpiece 20, and the abutment surface 2131 can abut against the end of the workpiece 20 near the rotating seat 100. This improves the tensile stress distribution of the workpiece 20 during the pressing process, allowing the workpiece 20 to retain high strength after pressing. When the workpiece 20 is a battery cell, the rolling surface 211 can roll the outer peripheral surface of the housing 21, and the contact surface 2131 can contact the end cap. In this way, the tensile stress of the weld seam generated by the rolling on the housing 21 and the end cap can be offset to a certain extent, so that the housing 21 and the end cap have a high connection strength.

[0195] The first roller pressing section 212 is frustum-shaped, and the second roller pressing section 213 is cylindrical. The end face of the second roller pressing section 213 facing the first roller pressing section 212 is the abutment surface 2131. The rotation axis of the pressure roller 210 is parallel to the rotation axis of the rotating seat 100. The first roller pressing section 212 is frustum-shaped, and the roller pressing surface 211 is a conical surface. By simply making the rotation axis of the pressure roller 210 parallel to the rotation axis of the rotating seat 100, the distance between the first intersection line 2111 and the rotation axis of the rotating seat 100 gradually increases along the direction from the rotating seat 100 towards the workpiece 20. The second roller pressing section 213 is cylindrical, which makes the area of ​​the abutment surface 2131 larger, thereby increasing the contact area with the workpiece 20, improving the tensile stress distribution of the workpiece 20 during the rolling process, and ensuring that the workpiece 20 still has high strength after rolling.

[0196] The above description is merely a preferred embodiment of this application and is 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 necking device for necking a workpiece, wherein, include: Rotating seat; Multiple roller pressing assemblies are arranged on the rotating seat around the rotation axis of the rotating seat. Each roller pressing assembly includes a self-rotating pressure roller. The pressure rollers of the multiple roller pressing assemblies are configured to cooperate in pressing the workpiece when the workpiece is close to the rotating seat. Each pressure roller includes a pressing surface for pressing the workpiece. The pressing surface intersects with a first cross-section of the pressure roller to form two intersecting lines. The first cross-section passes through the rotation axis of the pressure roller and the rotation axis of the rotating seat. The intersecting line closest to the rotation axis of the rotating seat is the first intersecting line. The distance between the first intersecting line and the rotation axis of the rotating seat gradually increases along the direction from the rotating seat towards the workpiece.

2. The necking device according to claim 1, wherein, The rolling assembly includes: A first adjusting seat is rotatably disposed on the rotating seat, and the pressure roller is rotatably disposed on the first adjusting seat about its own axis. The rotation axis of the first adjusting seat intersects with the rotation axis of the rotating seat, and the rotation axis of the first adjusting seat intersects with the rotation axis of the pressure roller. A locking element is used to lock the first adjusting seat and the rotating seat in an unlockable manner.

3. The necking device according to claim 1 or 2, wherein, The roller surface is cylindrical, and the angle between the rotation axis of the roller and the rotation axis of the rotating seat is acute.

4. The necking device according to claim 3, wherein, The angle between the rotation axis of the pressure roller and the rotation axis of the rotating seat is α, which satisfies: 0 < a ≤ 30°.

5. The necking device according to claim 4, wherein, 1°≤a≤8°。 6. The necking device according to claim 1, wherein, The roller surface is a conical surface, and the rotation axis of the roller is parallel to the rotation axis of the rotating seat.

7. The necking device according to claim 6, wherein, The pressure roller is detachably connected to the rotating base.

8. The necking device according to claim 6 or 7, wherein, The angle between the first intersecting line and the rotation axis of the rotating seat is b, which satisfies: 0 < b ≤ 30°.

9. The necking device according to claim 8, wherein, 1≤b≤8°。 10. The necking device according to claim 1, wherein, The pressure roller includes a first pressure section and a second pressure section. The minimum diameter of the second pressure section is greater than the maximum diameter of the first pressure section. The outer peripheral surface of the first pressure section is the pressure surface. The outer peripheral surfaces of the first pressure section and the second pressure section are connected by an abutment surface. The abutment surface is used to abut against one end of the workpiece near the rotating seat.

11. The necking device according to claim 10, wherein, The first roller pressing part is shaped like a frustum, the second roller pressing part is cylindrical, and the end face of the second roller pressing part facing the first roller pressing part is the abutment surface; The rotation axis of the pressure roller is parallel to the rotation axis of the rotating seat.

12. The necking device according to any one of claims 1-11, wherein, Embossing is provided on the roller surface.

13. The necking device according to any one of claims 1-12, wherein, Along the extension direction of the rotation axis of the pressure roller, the dimension of the roller pressing surface is c, where 5mm≤c≤30mm.

14. The necking device according to claim 13, wherein, 10mm≤c≤20mm.

15. The necking device according to any one of claims 1-14, wherein, The number of the roller pressing components is n, which satisfies: 2≤n≤4.

16. The necking device according to any one of claims 1-15, wherein, The narrowing device includes a first driving mechanism and a second driving mechanism. The first driving mechanism is connected to the rotating seat and the second driving mechanism. The first driving mechanism is configured to drive the rotating seat to rotate, and the second driving mechanism is configured to drive the rotating seat to move along the extension direction of the rotation axis of the rotating seat.

17. The necking device according to any one of claims 1-16, wherein, The necking device includes a first dust removal mechanism, which is used to remove dust during the process of the pressure roller pressing the workpiece.

18. The necking device according to claim 17, wherein, The first dust removal mechanism includes a dust removal hood disposed on the rotating seat, the dust removal hood having a dust removal space for inserting the workpiece, and the pressure roller being at least partially located within the dust removal space.

19. The necking device according to claim 18, wherein, The dust removal hood has a window at the position corresponding to the pressure roller, and a part of the pressure roller extends into the dust removal space through the window.

20. The necking device according to any one of claims 1-19, wherein, The narrowing device further includes a clamping mechanism, which is spaced apart from the rotating seat along the extension direction of the rotation axis of the rotating seat, and is used to clamp the workpiece.

21. The necking device according to claim 20, wherein, The clamping mechanism includes a first clamping member and a second clamping member, which are used to clamp the workpiece. At least one of the first clamping member and the second clamping member is provided with an adsorption member, which is used to adsorb the workpiece.

22. The necking device according to any one of claims 1-21, wherein, The narrowing device further includes a stop member, which is arranged opposite to the rotating seat along the extension direction of the rotation axis of the rotating seat. The stop member is used to stop the end of the workpiece away from the rotating seat.

23. The necking device according to claim 22, wherein, The workpiece is a battery cell, and the battery cell includes electrode terminals; The abutment is provided with a dust removal hole, which is used to accommodate the electrode terminal.

24. The necking device according to claim 23, wherein, The electrode terminal is provided with a liquid injection hole; The abutment includes a docking portion for insertion into the injection hole. A dust removal channel is formed inside the docking portion. At least a portion of the docking portion extends into the dust removal hole. A receiving cavity is formed between the docking portion and the hole wall of the dust removal hole. The receiving cavity communicates with the dust removal channel. The abutment is provided with an air inlet communicating with the receiving cavity. The receiving cavity is used to accommodate at least a portion of the electrode terminal when the docking portion is inserted into the injection hole.

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