Winding member assembly, winding device and winding method

Abstract

Disclosed in the present application are a winding member assembly, a winding device and a winding method. The winding member assembly comprises a first winding member and second winding members, the first winding member comprising two first sub-winding members capable of moving with respect to each other in a first direction, and the second winding members being respectively arranged on the two sides of the first winding member in a second direction. In a first state, the outer peripheral walls of the second winding members and the outer peripheral walls of the first sub-winding members are located on the same preset cylindrical surface. In a second state, the second winding members are located inside the preset cylindrical surface, and at least part of each second winding member extends into accommodating chambers via corresponding mating ports, such that the width of the winding member assembly in the second direction in the second state is smaller than the width of the winding member assembly in the second direction in the first state.

Description

Winding needle assembly, winding device and winding method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311229325.2 and application date of September 22, 2023, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of winding technology, and in particular to a winding needle assembly, a winding device and a winding method. Background Art

[0004] In related technologies, a wound electrode assembly typically requires a winding device to wind the electrode sheet and separator to form the electrode assembly. The winding device utilizes a winding needle assembly to wind the electrode sheet and separator. After the winding needle assembly is completed, the electrode sheet and separator are removed from the winding needle assembly. Due to the lack of support, the electrode assembly struggles to maintain its original shape due to its own gravity, and the upper portion of the electrode assembly is prone to collapse, causing the electrode sheet to wrinkle, impacting the reliability and safety of the electrode assembly.

[0005] Summary of the Invention

[0006] The present application proposes a winding needle assembly, a winding device and a winding method, which can improve the ability of the coil to maintain its own shape and shape stability after it is removed from the winding needle assembly, reduce the probability of the coil collapsing, and when the coil is an electrode assembly, reduce the probability of wrinkling of the electrode.

[0007] 14. The repairing kit for automotive dents, according to claim 13, wherein the foot stand comprises a through-hole, and the two foot pieces comprise two bosses, wherein the bosses comprise a through-hole, a screw bolt, and a nut. The through-hole comprises a through-hole, and the bosses comprise a through-hole, a screw bolt, and a nut. The through-hole comprises a through-hole, and the two foot pieces comprise a through-hole. The through-holes are

[0008] In the above technical solution, the first winding needle comprises two first sub-winding needles arranged opposite each other and movable relative to each other along a first direction. The winding needle assembly is switchable between a first state and a second state. In the second state, the width of the winding needle assembly in the second direction is smaller than that in the first state. This allows the second winding needle to not support the corresponding portion of the coil in the second state. Furthermore, the winding needle assembly can provide clearance for the coil when the first winding needle is stretched. This allows the coil to be stretched at least once before being removed from the winding needle assembly, flattening the coil. This improves the coil's ability to maintain its shape and shape stability after removal from the winding needle assembly, reducing the probability of collapse due to gravity and other factors, thereby improving the coil's reliability. Furthermore, the first sub-winding needle provides clearance for the second winding needle, facilitating smooth switching between the first and second states and conserving axial space occupied by the winding needle assembly. If the coil is an electrode assembly, this can improve reliability issues such as diaphragm folding and electrode plate wrinkling, thereby enhancing the safety of the electrode assembly.

[0009] In some embodiments, in the first state, the second winding needle is located outside the first sub-winding needle.

[0010] In the above technical solution, by arranging that the second winding needle is located outside the first sub-winding needle in the first state, it is convenient to reduce the volume and occupied space of the second winding needle to a certain extent while satisfying the supporting function of the second winding needle for the coiled material, which is beneficial to reducing the occupation of the internal space of the first winding needle by the second winding needle in the first state. When the winding needle assembly switches to the second state, it is beneficial for the second winding needle to make full use of the internal space of the first winding needle; especially when there are multiple second states and the multiple second states are respectively from the first gear to the Nth gear, the above setting is beneficial to appropriately increase the number of second states.

[0011] In some embodiments, at least one second winding needle includes two second sub-winding needles spaced apart along the first direction. In the first state, the outer peripheral wall of the second sub-winding needle and the outer peripheral wall of the first sub-winding needle are both on a preset cylindrical surface; in the second state, at least a portion of the second sub-winding needle extends into the corresponding accommodating cavity so that the second sub-winding needle is located on the inner side of the preset cylindrical surface.

[0012] In the above technical solution, by setting at least one second winding needle including two second sub-winding needles spaced apart along the first direction, the space between the two second sub-winding needles can provide a passing space for the coiled material, so as to achieve the fixation of the coiled material.

[0013] In some embodiments, a side wall of at least one first sub-winding needle facing another first sub-winding needle is formed with an avoidance opening, and the avoidance opening is connected to the accommodating cavity and the corresponding two matching openings respectively, so as to be suitable for avoiding the corresponding second sub-winding needle.

[0014] In the above technical solution, by setting up an avoidance opening, an avoidance can be provided for the switching movement of the second sub-winding needle when the winding needle assembly switches between the first state and the second state, which is conducive to further expanding the movement space provided for the second winding needle when the winding needle assembly switches between the first state and the second state. To a certain extent, the distance between the two second sub-winding needles in the first direction can be appropriately reduced to adapt to increasing the proportion of the outer peripheral wall of the second sub-winding needle in the preset cylindrical surface in the circumferential direction of the winding needle assembly, thereby increasing the support range of the outer peripheral wall of the second winding needle on the circumferential direction of the coil in the first state.

[0015] In some embodiments, a partition is provided in the accommodating cavity, and the partition is connected to the two opposite side walls of the accommodating cavity to separate the accommodating cavity into two chambers arranged in sequence along the second direction, and the two chambers correspond to the two second winding pins respectively.

[0016] In the above technical solution, a partition is provided in the accommodating cavity to divide the accommodating cavity into two chambers, thereby improving the structural stability of the accommodating cavity and the structural reliability of the needle winding assembly while meeting the accommodating requirements of the second needle winding in the second state.

[0017] In some embodiments, the winding needle assembly has a center line extending along the second direction, and the two first sub-winding needles are respectively arranged on both sides of the center line in the first direction; and / or, the two second sub-winding needles of at least one second winding needle are respectively arranged on both sides of the center line in the first direction.

[0018] In the above technical solution, by arranging two first sub-winding needles respectively on both sides of the center line in the first direction, and / or the two second sub-winding needles of the second winding needle respectively on both sides of the center line in the first direction, the spacing area between the two first sub-winding needles and the spacing area between the two second sub-winding needles of the second winding needle can be arranged relative to or staggered, so that the coil can be passed through the spacing area between the two second sub-winding needles to the spacing area between the two first sub-winding needles, which is convenient for subsequent clamping or subsequent continued threading.

[0019] In some embodiments, the winding needle assembly further includes: two clamping members arranged opposite to each other, the two clamping members can move relative to each other to clamp the coiled material, and the two clamping members are respectively arranged on the two first sub-winding needles.

[0020] In the above technical solution, a clamping member is provided so that the coil can be clamped by the clamping member to achieve fixation of the coil, thereby achieving winding of the coil on the outer peripheral wall of the winding needle assembly; in addition, due to the provision of the clamping member, the position of the first sub-winding needle does not need to be changed when the coil is clamped and fixed, that is, the position of the first sub-winding needle is relatively fixed, which makes it easier to make the preset cylindrical surface relatively fixed in the first state, thereby helping to reduce the position requirements of the second winding needle in the first state and the second state, and during the winding process, there is no need to adjust the position of the first sub-winding needle, which helps to simplify the winding steps of the winding needle assembly.

[0021] In some embodiments, the outer circumferential walls of the two first sub-winding needles are arranged opposite to each other, and a groove is formed on the outer circumferential wall of each first sub-winding needle. The grooves of the two first sub-winding needles are arranged opposite to each other along the radial direction of the winding needle assembly.

[0022] In the above technical solution, grooves are respectively provided on the outer peripheral wall of each first sub-winding needle to provide a mating space with the blanking assembly so as to realize the separation of the coil and the winding needle assembly and proceed to the next process; at the same time, since the two grooves are arranged radially opposite to each other along the radial direction of the winding needle assembly, the two blanking assemblies can be arranged radially opposite to each other, which is convenient for directly stretching the coil after removing the coil to further flatten it, and the coil is subjected to more balanced force, reducing the risk of coil deformation.

[0023] In some embodiments, the second winding needle moves within the cross section of the winding needle assembly to switch the winding needle assembly between the first state and the second state.

[0024] In the above technical solution, by setting the second winding needle to move within the cross-section of the winding needle assembly so that the winding needle assembly can switch between the first state and the second state, the movement space required for the second winding needle when switching between the above states can be reduced, saving the space required for the winding needle assembly to work.

[0025] In some embodiments, the at least one second winding needle is movable relative to the first winding needle along the second direction.

[0026] In the above technical solution, by setting at least one second winding needle to be movable relative to the first winding needle along the second direction, it is beneficial to simplify the movement mode of the at least one second winding needle, and at the same time, it can further reduce the movement space required for the at least one second winding needle during the switching of the winding needle assembly between the first state and the second state.

[0027] In some embodiments, the second states are multiple and are respectively from the first gear to the Nth gear. From the first gear to the Nth gear, the width of the winding needle assembly in the second direction decreases.

[0028] In the above technical solution, multiple second states are set from the first gear to the Nth gear, and from the first gear to the Nth gear, the width of the winding needle assembly in the second direction is reduced, so as to improve the shape stability of the coil after it is removed from the winding needle assembly, while adapting to the different requirements of different coils for the number of stretching times, flatness, etc.

[0029] In the second aspect, an embodiment of the present application provides a winding device, comprising the above-mentioned winding needle assembly, a first drive mechanism and a second drive mechanism, the first drive mechanism being used to drive the winding needle assembly to rotate around its central axis, and the second drive mechanism being used to drive at least one first sub-winding needle to move along a first direction.

[0030] In the above technical solution, since the winding device adopts the above-mentioned winding needle assembly, and the winding needle assembly can improve the ability of the coil to maintain its own shape and shape stability after the coil is removed from the winding needle assembly, the winding device can reduce the probability of collapse of the coil and improve the reliability of the use of the coil; if the coil is an electrode assembly, it can improve reliability problems such as folding of the diaphragm and wrinkling of the electrode, thereby improving the safety of the electrode assembly.

[0031] In some embodiments, in the first state, the second winding needle is located outside the first sub-winding needle; the winding device also includes: a third driving mechanism, the third driving mechanism is used to drive the second winding needle to move relative to the first winding needle along the second direction, so that the winding needle assembly switches between the first state and the second state.

[0032] In the above technical solution, the movement mode of the second winding needle is simple, which can further reduce the movement space required by the second winding needle during the switching of the winding needle assembly between the first state and the second state.

[0033] In a third aspect, an embodiment of the present application provides a winding method, wherein a winding needle assembly includes a first winding needle and a second winding needle, the first winding needle includes two first sub-winding needles arranged opposite to each other in a first direction and capable of moving relative to each other in the first direction, a receiving cavity is formed in each first sub-winding needle, and the receiving cavity penetrates the two side walls of the first sub-winding needle in the second direction to form matching openings respectively, and a second winding needle is provided on both sides of the first winding needle along the second direction, and each second winding needle can move relative to the first sub-winding needle, and the winding needle assembly is configured to switch between a first state and a second state, and in the first state, the outer peripheral wall of the second winding needle is aligned with the outer peripheral wall of the first sub-winding needle The outer peripheral wall is on the same preset cylindrical surface; in the second state, the second winding needle is located on the inner side of the preset cylindrical surface and at least part of the second winding needle extends into the accommodating cavity through the corresponding matching opening, so that the width of the winding needle assembly in the second direction in the second state is smaller than the width of the winding needle assembly in the second direction in the first state, and the first direction and the second direction are perpendicular to the axial direction of the winding needle assembly. The winding method includes: the winding needle assembly winds the coil in the first state until the preset conditions are met, and the winding needle assembly stretches the coil at least once. During the stretching process, the winding needle assembly switches to the second state and increases the distance between the two first sub-winding needles in the first direction.

[0034] In the above technical solution, the winding needle assembly stretches the coil at least once before removing the coil from the winding needle assembly, which can improve the coil's ability to maintain its own shape and shape stability after it is removed from the winding needle assembly. Therefore, the winding method can reduce the probability of collapse of the coil and improve the reliability of the coil. If the coil is an electrode assembly, it can improve reliability issues such as folding of the diaphragm and wrinkling of the electrode, thereby improving the safety of the electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] FIG1 is a schematic diagram of a winding needle assembly provided in some embodiments of the present application;

[0037] FIG2 is a schematic diagram of the first winding needle and the clamping member shown in FIG1 ;

[0038] FIG3 is another schematic diagram of the winding needle assembly shown in FIG1 ;

[0039] FIG4 is another schematic diagram of the first winding needle and the clamping member shown in FIG2 ;

[0040] FIG5 is another schematic diagram of the first winding needle shown in FIG4 ;

[0041] FIG6 is a schematic diagram of the coiling needle assembly shown in FIG1 winding a coil;

[0042] FIG7 is a schematic diagram of a blanking assembly stretching a coiled material according to some embodiments of the present application;

[0043] FIG8 is a schematic flow chart of a winding method provided in some embodiments of the present application.

[0044] Reference numerals:

[0045] Needle assembly 10, center axis L1, center line L2, blanking assembly 20, coil 30,

[0046] First winding needle 1, first sub-winding needle 11, accommodating cavity 11a, matching opening 11b, avoidance opening 11c, installation groove 11d, groove 11e, cavity 11f,

[0047] Second winding needle 2, second sub-winding needle 21,

[0048] Separator 3, clamping piece 4, inner clamping needle 6, outer clamping needle 7. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0051] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0052] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0053] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the terms such as thickness, length, and width of various components in the embodiments of the present application shown in the drawings should not constitute any limitation on the present application.

[0054] The term "plurality" used in this application refers to two or more (including two).

[0055] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0056] The battery referred to in the embodiments of this application refers to a single physical module that includes multiple battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or battery pack. A battery module generally includes multiple battery cells. A battery generally includes a casing for enclosing multiple battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, the battery may also not include a casing.

[0057] Illustratively, a battery includes multiple battery cells, which can be connected in series, in parallel, or in a hybrid configuration. Hybrid configuration refers to multiple battery cells being connected both in series and in parallel. Illustratively, a battery cell typically includes a housing, an electrode assembly, and an electrolyte. The housing is used to house the electrode assembly and the electrolyte, and is provided with at least one positive electrode post and at least one negative electrode post. An electrode assembly includes one or more electrode assemblies, which are formed by stacking or winding positive and negative electrode sheets and separators.

[0058] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection. Alternatively, the battery cell assembly may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0059] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter. The multiple stacked negative electrode tabs are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode column to form an electrical connection between the negative electrode tab and the negative electrode column. The material of the diaphragm is not limited, and can be, for example, polypropylene or polyethylene.

[0060] In the related art, a wound electrode assembly typically requires a winding device to wind the electrode sheet and separator to form the electrode assembly. Typically, the winding device uses a winding needle assembly to wind the electrode sheet and separator. After the winding needle assembly is completed, the electrode sheet and separator are removed from the winding needle assembly and stretched using a blanking assembly to adjust their shape. For example, a roughly cylindrical electrode assembly can be flattened after stretching to facilitate subsequent shaping.

[0061] However, after the electrode sheets and diaphragms are removed from the winding needle assembly, due to the lack of support, electrode assemblies with smaller winding widths can basically maintain their shape after removal. For example, electrode assemblies with smaller diameters can basically maintain their cylindrical shape after being removed from the winding needle assembly. However, for electrode assemblies with larger winding widths, since most of the electrode assembly is suspended in the air and is only clamped by the blanking assembly, the electrode assembly will find it difficult to maintain its original shape due to its own gravity before the blanking assembly stretches the electrode assembly. The upper part of the electrode assembly is prone to collapse, affecting the subsequent shaping process. At the same time, the collapse of the electrode assembly is prone to problems such as diaphragm folding and electrode sheet wrinkling, affecting the reliability of the electrode assembly. For example, for electrode assemblies with larger diameters (e.g., diameters greater than 400mm), after being removed from the winding needle assembly, the suspended portion is prone to collapse downward under the action of gravity, making it difficult to maintain its original cylindrical shape.

[0062] Based on the above considerations, and to facilitate maintaining the original shape of the electrode assembly after removal from the winding needle assembly, a winding needle assembly is proposed. The winding needle assembly includes a first winding needle and a second winding needle. The first winding needle includes two first sub-winding needles arranged opposite each other in a first direction and capable of relative movement in the first direction. Each first sub-winding needle has a receiving cavity formed therein, the receiving cavity extending through two side walls of the first sub-winding needle in the second direction to form respective mating openings. A second winding needle is provided on either side of the first winding needle in the second direction, and each second winding needle is movable relative to the first sub-winding needle. The winding needle assembly is configured to switch between a first state and a second state. In the first state, the outer peripheral wall of the second winding needle and the outer peripheral wall of the first sub-winding needle are located on the same predetermined cylindrical surface. In the second state, the second winding needle is located inside the predetermined cylindrical surface, and at least a portion of the second winding needle extends into the receiving cavity through the corresponding mating opening, such that the width of the winding needle assembly in the second direction in the second state is smaller than the width of the winding needle assembly in the first state. The first and second directions are perpendicular to the axial direction of the winding needle assembly.

[0063] In the above technical solution, the first winding needle comprises two first sub-winding needles arranged opposite each other and movable relative to each other along a first direction. The winding needle assembly is switchable between a first state and a second state. In the second state, the width of the winding needle assembly in the second direction is smaller than that in the first state. This allows the second winding needle to not support the corresponding portion of the coil in the second state. Furthermore, the winding needle assembly can provide clearance for the coil when the first winding needle is stretched. This allows the coil to be stretched at least once before being removed from the winding needle assembly, flattening the coil. This improves the coil's ability to maintain its shape and shape stability after removal from the winding needle assembly, reducing the probability of collapse due to gravity and other factors, thereby improving the coil's reliability. Furthermore, the first sub-winding needle provides clearance for the second winding needle, facilitating smooth switching between the first and second states and conserving axial space occupied by the winding needle assembly. If the coil is an electrode assembly, this can improve reliability issues such as diaphragm folding and electrode plate wrinkling, thereby enhancing the safety of the electrode assembly.

[0064] The present application provides an electrical device using the battery of the present disclosure as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0065] For the convenience of explanation, the following embodiments take the electrical device as a vehicle as an example. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The vehicle is provided with a battery, and the battery can be arranged at the bottom, head or tail of the vehicle. The battery can be used to power the vehicle, for example, the battery can be used as an operating power source for the vehicle. The vehicle may also include a controller and a motor, and the controller is used to control the battery to power the motor, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery can be used not only as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0066] Please refer to Figures 1-3. Figure 1 is a schematic diagram of a winding needle assembly according to some embodiments of the present application. Figure 2 is a schematic diagram of the first winding needle and the clamping member shown in Figure 1. Figure 3 is another schematic diagram of the winding needle assembly shown in Figure 1. In the embodiments of the present application, the winding needle assembly 10 includes a first winding needle 1, which includes two first sub-winding needles 11 arranged opposite to each other along a first direction. The two first sub-winding needles 11 are capable of relative movement along the first direction. At least one of the first sub-winding needles 11 can move toward or away from the other first sub-winding needle 11 along the first direction to increase or decrease the distance between the two first sub-winding needles 11 in the first direction.

[0067] The winding needle assembly 10 also includes a second winding needle 2, and a second winding needle 2 is provided on both sides of the first winding needle 1 along the second direction. The winding needle assembly 10 is configured to be able to switch between a first state and a second state; the first direction and the second direction are perpendicular to the axial direction of the winding needle assembly 10, and the radial direction of the winding needle assembly 10 can be a direction passing through the central axis L1 of the winding needle assembly 10 in a radial plane. The radial plane is perpendicular to the central axis L1 of the winding needle assembly 10, then the winding needle assembly 10 has multiple radial directions, and the first direction and the second direction can be understood as two of the multiple radial directions of the winding needle assembly 10.

[0068] In the first state, the outer peripheral wall of the second winding needle 2 and the outer peripheral wall of the first sub-winding needle 11 are on the same preset cylindrical surface. The outer peripheral wall of the second winding needle 2 can be understood as the side of the second winding needle 2 facing away from the first winding needle 1, so the outer peripheral walls of the two second winding needles 2 are arranged back to back, and the outer peripheral wall of the first sub-winding needle 11 can be understood as the side wall of the first sub-winding needle 11 facing away from the other first sub-winding needle 11, so the outer peripheral walls of the two first sub-winding needles 11 are arranged back to back; in the second state, the second winding needle 2 is located on the inner side of the preset cylindrical surface, then on the cross section of the winding needle assembly 10, the orthographic projection of the second winding needle 2 is located on the inner side of the orthographic projection of the preset cylindrical surface, so that when the second winding needle 2 is in the second state, the width of the winding needle assembly 10 in the second direction is smaller than the width of the winding needle assembly 10 in the second direction when the second winding needle 2 is in the first state, and the cross section of the winding needle assembly 10 is perpendicular to the center axis L1 of the winding needle assembly 10.

[0069] It can be seen that the winding needle assembly 10 of the embodiment of the present application can be used to wind the electrode assembly. During winding, the winding needle assembly 10 can rotate around its central axis L1 to wind the anode plate, cathode plate and diaphragm together to form a wound electrode assembly; of course, the application scenario of the winding needle assembly 10 is not limited to this.

[0070] The winding needle assembly 10 is used for winding electrode assemblies. The winding needle assembly 10 is in a first state, and the winding needle assembly 10 starts to wind the coil 30. At this time, the outer peripheral wall of the first sub-winding needle 11 and the outer peripheral wall of the second winding needle 2 can jointly support the coil 30. The winding needle assembly 10 can wind the coil 30 along the preset cylindrical surface to the outside of the preset cylindrical surface, and the shape of the wound coil 30 is basically the same as the preset cylindrical surface; after the coil 30 is wound to a certain length or the coil 30 is wound to a certain thickness, the winding needle assembly 10 stops rotating, and the winding needle assembly 10 can switch to the second state. Since the second winding needle 2 is located on the inner side of the preset cylindrical surface, the width of the winding needle assembly 10 in the second direction is reduced, and the two first sub-winding needles 11 are controlled to move away from each other along the first direction, that is, at least one first sub-winding needle 11 moves along the first direction away from the other first sub-winding needle 11, so that the two first sub-winding needles 11 can stretch the coil 30 at least once. During the above-mentioned stretching process, since the second winding needle 2 provides an avoidance space for the change in the shape of the coil 30, the width of the coil 30 in the second direction can be reduced and the width of the coil 30 in the first direction can be increased. The stretching process can change the cross-sectional shape of the cylindrical structure corresponding to the coil 30; after the coil 30 is wound to a certain extent (for example, the first winding needle 1 stretches the coil 30 a preset number of times), the coil 30 is removed from the winding needle assembly 10.

[0071] Obviously, the above-mentioned operation on the coil 30 can reduce the suspended height of the coil 30 in the second direction when the coil 30 is removed from the winding needle assembly 10, that is, reduce the suspended height of the parts on both sides of the coil 30 in the second direction when the winding needle assembly 10 withdraws the needle from the coil 30, so as to effectively reduce the risk that the coil 30 is difficult to maintain its original shape due to the influence of gravity of the coil 30, especially when the second direction is the up and down direction when the needle is withdrawn, thereby reducing the probability of collapse of the coil 30 after being removed from the winding needle assembly 10, improving the shape stability of the coil 30, facilitating the subsequent shaping process of the coil 30, and at the same time, to a certain extent, improving reliability problems such as diaphragm folding and electrode wrinkling, thereby improving the reliability and safety of the coil 30.

[0072] Especially for electrode assemblies with a large width (for example, the width of the electrode assembly in the second direction during winding is greater than 400 mm, etc.) or when the preset cylinder is a cylindrical surface and the diameter of the preset cylinder is large (for example, the diameter of the preset cylinder is greater than 400 mm, etc.), when the coil 30 is removed from the winding needle assembly 10 after the winding structure, the coil 30 is only clamped by the blanking assembly 20, and at least part of the coil 30 is in a suspended state. Before the blanking assembly 20 stretches the coil 30, the coil 30 is easily collapsed due to the influence of gravity, affecting subsequent processes. The winding needle assembly 10 of the embodiment of the present application can switch the winding needle assembly 10 to the second state before the coil 30 is removed from the winding needle assembly 10, and move the two first sub-winding needles 11 away from each other to achieve stretching of the coil 30. Therefore, when the coil 30 is removed, the suspended height of the coil 30 is reduced due to the stretching process, which improves the stability of the coil 30 in its original state for subsequent processing.

[0073] For example, during the process of winding the coil 30, the first direction and the second direction of the winding needle assembly 10 change accordingly. When the winding is completed, the winding needle assembly 10 stops rotating. The first direction can be the left and right direction, and the second direction can be the up and down direction. Then, the upper part of the coil 30 is prone to collapse after the needle is withdrawn. The winding needle assembly 10 in the embodiment of the present application can stretch the coil 30 before withdrawing the needle to reduce the suspended height of the upper part of the coil 30, thereby improving the shape stability of the coil 30.

[0074] It is understood that in the embodiment of the present application, the predetermined cylindrical surface can be a cylindrical surface, an elliptical cylindrical surface, or a diamond cylindrical surface, etc. In other words, the cross-sectional shape of the winding needle assembly 10 can be approximately circular, elliptical, or diamond-shaped, etc. For example, as shown in the figure, the predetermined cylindrical surface is a cylindrical surface, the outer peripheral wall of the first sub-winding needle 11 is a circular arc surface, and the outer peripheral wall of the second winding needle 2 is also a circular arc surface.

[0075] Among them, please refer to Figures 1, 2 and 4. Figure 4 is another schematic diagram of the first winding needle 1 and the clamping member 4 shown in Figure 2. A accommodating cavity 11a is formed in each first sub-winding needle 11, and the accommodating cavity 11a penetrates the two side walls of the first sub-winding needle 11 in the second direction to form matching openings 11b respectively. Then, a side wall of each first sub-winding needle 11 facing one of the second winding needles 2 is formed with a matching opening 11b, and a side wall of each first sub-winding needle 11 facing the other second winding needle 2 is also formed with a matching opening 11b; each second winding needle 2 can move relative to the first sub-winding needle 11 to realize the switching of the winding needle assembly 10 between the first state and the second state.

[0076] Then, in the second state, the second winding needle 2 is located inside the preset cylindrical surface, and at least a portion of the second winding needle 2 extends into the accommodating cavity 11a through the corresponding mating opening 11b. In this second state, a portion of the second winding needle 2 extends into the corresponding first sub-winding needle 11, while another portion is located outside the first sub-winding needle 11, or the entire second winding needle 2 extends into the corresponding first sub-winding needle 11. The accommodating cavity 11a provides a clearance for the movement of the second winding needle 2, thereby expanding the movement space provided by the winding needle assembly 10 when switching between the first and second states, allowing for smooth switching of the second winding needle 2. This also helps to reduce the axial length of the winding needle assembly 10, saving the space occupied by the winding needle assembly 10 in the axial direction.

[0077] It can be understood that when the winding needle assembly 10 is in the second state, the above-mentioned at least part of the second winding needle 2 can extend into the corresponding first sub-winding needle 11 through at least one matching opening 11b located on the same side of the first sub-winding needle 11 in the second direction.

[0078] In the above technical solution, the first winding needle 1 includes two first sub-winding needles 11 that are relatively arranged along the first direction and can move relatively along the first direction, and the winding needle assembly 10 can switch between the first state and the second state. In the second state, the width of the winding needle assembly 10 in the second direction is smaller than the width of the winding needle assembly 10 in the second direction in the first state, so that in the second state, the second winding needle 2 can not support the corresponding part of the coil 30, and at the same time, it can avoid the coil 30 when the first winding needle 1 stretches the coil 30, so that the coil 30 can be stretched on the self-winding needle assembly 10. Before removal, the winding needle assembly 10 can stretch the material coil 30 at least once, flattening it. This improves the material coil 30's ability to maintain its shape and shape stability after removal from the winding needle assembly 10, reducing the probability of the material coil 30 collapsing due to gravity and other factors, thereby improving the reliability of the material coil 30. Furthermore, the first sub-winding needle 11 provides clearance for the second winding needle 2, facilitating smooth switching between the first and second states of the winding needle assembly 10 and conserving the axial space occupied by the winding needle assembly 10. If the material coil 30 is an electrode assembly, this can improve reliability issues such as diaphragm folding and electrode plate wrinkling, reducing the probability of electrode plate wrinkling and thus improving the safety of the electrode assembly.

[0079] It is worth noting that the embodiment of the present application does not impose any specific restrictions on the manner in which the winding needle assembly 10 switches between the first state and the second state; for example, the second winding needle 2 switches between the first state and the second state by moving relative to the first winding needle 1, for example, the second winding needle 2 can move relative to the first winding needle 1, or the second winding needle 2 can move and rotate relative to the first winding needle 1, etc. For example, the second winding needle 2 itself can be deformed to achieve the switching of the winding needle assembly 10 between the first state and the second state. It is only necessary to make the second winding needle 2 located on the inner side of the preset cylindrical surface when the winding needle assembly 10 is in the second state and at least part of the second winding needle 2 extends into the accommodating cavity 11a through the corresponding matching opening 11b, so that the width of the winding needle assembly 10 in the second direction in the second state is smaller than the width of the winding needle assembly 10 in the second direction in the first state. In this way, when the winding needle assembly 10 is in the second state, the second winding needle 2 does not effectively support the corresponding part of the coil 30, so as to avoid the change in shape of the coil 30 when the first winding needle 1 stretches the coil 30.

[0080] Please refer to FIG. 1 and FIG. 3 . In some embodiments, in the first state, the second winding needle 2 is located outside the first sub-winding needle 11 .

[0081] In the above technical solution, by arranging that the second winding needle 2 is located outside the first sub-winding needle 11 in the first state, it is convenient to reduce the volume and occupied space of the second winding needle 2 to a certain extent while satisfying the supporting function of the second winding needle 2 for the coil 30, which is beneficial to reducing the occupation of the internal space of the first winding needle 1 by the second winding needle 2 in the first state. When the winding needle assembly 10 switches to the second state, it is beneficial for the second winding needle 2 to make full use of the internal space of the first winding needle 1; especially when there are multiple second states and the multiple second states are respectively from the first gear to the Nth gear, the above setting is beneficial to appropriately increase the number of second states.

[0082] Please refer to Figures 1 to 4. In some embodiments, at least one second winding needle 2 includes two second sub-winding needles 21 spaced apart along the first direction. The spacing between the two second sub-winding needles 21 can provide a passing space for the coil 30 before winding begins, so as to achieve the fixation of the coil 30 (for example, the clamping of the coil 30), etc. For example, the coil 30 can pass through the space between the two second sub-winding needles 21 from the outside of the winding needle assembly 10 to the inside of the winding needle assembly 10. At this time, the coil 30 can be directly clamped or indirectly clamped by the two first sub-winding needles 11, or directly clamped or indirectly clamped by the two second sub-winding needles 21; of course, there are some examples in which each second winding needle 2 includes two second sub-winding needles 21 spaced apart along the first direction. The coil 30 can pass through the space between the two second sub-winding needles 21 of one of the second winding needles 2 from the outside of the winding needle assembly 10 to the inside of the winding needle assembly 10, and pass through the space between the two second sub-winding needles 21 of the other second winding needle 2 from the inside of the winding needle assembly 10 to the outside of the winding needle assembly 10. At this time, the coil 30 can be clamped by other clamping components provided outside the winding needle assembly 10; etc.

[0083] Among them, in the first state, the outer peripheral wall of the second sub-winding needle 21 and the outer peripheral wall of the first sub-winding needle 11 are both on the preset cylindrical surface; in the second state, at least part of the second sub-winding needle 21 extends into the corresponding accommodating cavity 11a so that the second sub-winding needle 21 is located on the inner side of the preset cylindrical surface, then the above-mentioned at least part of the second sub-winding needle 21 extends into a corresponding first sub-winding needle 11, or the above-mentioned at least part of the second sub-winding needle 21 extends into two first sub-winding needles 11.

[0084] Then, for a single second winding needle 2, it can be constructed as follows: in the second state, at least part of one of the second sub-winding needles 21 extends into one of the first sub-winding needles 11, and at least part of the other second sub-winding needle 21 extends into the other first sub-winding needle 11; or, in the second state, at least part of one of the second sub-winding needles 21 extends into one of the first sub-winding needles 11, and at least part of the other second sub-winding needle 21 extends into one of the above-mentioned first sub-winding needles 11 and the other first sub-winding needle 11 (for example, a side wall of each first sub-winding needle 11 facing the other first sub-winding needle 11 is formed with the avoidance opening 11c described below).

[0085] In the above technical solution, by setting at least one second winding needle 2 including two second sub-winding needles 21 spaced apart along the first direction, the spacing between the two second sub-winding needles 21 can provide a passing space for the coil 30 to achieve the fixation of the coil 30.

[0086] For example, as shown in Figures 1 to 4, the first direction is the left-right direction, and the second direction is the up-down direction. The first winding needle 1 includes two first sub-winding needles 11 arranged along the left-right direction. The two first sub-winding needles 11 can move toward each other or move away from each other along the left-right direction. The first winding needle 1 is provided with a second winding needle 2 on the upper and lower sides respectively. Each second winding needle 2 includes two second sub-winding needles 21 spaced apart along the left-right direction, so that each first sub-winding needle 11 is provided with a second sub-winding needle 21 on the upper and lower sides respectively; an accommodating cavity 11a is formed in the first sub-winding needle 11, and the accommodating cavity 11a passes through the upper side wall of the first sub-winding needle 11 to form a matching opening 11b, and the accommodating cavity 11a penetrates the lower side wall of the first sub-winding needle 11 to form a matching opening 11b; for a single second sub-winding needle 21, the upper second sub-winding needle 21 is suitable for extending into one first sub-winding needle 11 through the matching opening 11b on the upper side of the first sub-winding needle 11, or the upper second sub-winding needle 21 is suitable for extending into two first sub-winding needles 11 through the matching opening 11b on the upper side of the first sub-winding needle 11. Similarly, the lower second sub-winding needle 21 is suitable for extending into one first sub-winding needle 11 through the matching opening 11b on the lower side of the first sub-winding needle 11, or the lower second sub-winding needle 21 is suitable for extending into two first sub-winding needles 11 through the matching opening 11b on the lower side of the first sub-winding needle 11.

[0087] Optionally, the second winding needle 2 includes two second sub-winding needles 21 spaced apart along the first direction. When the second winding needle 2 is configured to be movable along the second direction relative to the first winding needle 1 to achieve switching of the winding needle assembly 10 between the first state and the second state, each second sub-winding needle 21 can move along the second direction relative to the first sub-winding needle 11 to change the distance between the second sub-winding needle 21 and the corresponding first sub-winding needle 11 in the second direction, while allowing the second sub-winding needle 21 to enter and exit the corresponding first sub-winding needle 11 through the corresponding mating port 11b.

[0088] For example, taking the first direction as the left-right direction, with one second sub-winding needle 21 corresponding to one first sub-winding needle 11 and another second sub-winding needle 21 corresponding to another first sub-winding needle 11 as an example: in the first state, all second sub-winding needles 21 are located outside the first winding needle 1, and the outer peripheral wall of each second sub-winding needle 21 and the outer peripheral wall of each first sub-winding needle 11 are both located on the preset cylindrical surface; in the second state, the left second sub-winding needle 21 can be inserted into the left first sub-winding needle 11 through the corresponding matching opening 11b, and the right second sub-winding needle 21 can be inserted into the right first sub-winding needle 11 through the corresponding matching opening 11b. For example, the length of the matching opening 11b in the first direction is greater than the width of the corresponding second sub-winding needle 21 in the first direction, and the width of the matching opening 11b in the axial direction of the winding needle assembly 10 is greater than the thickness of the corresponding second sub-winding needle 21 in the axial direction of the winding needle assembly 10, so that the matching opening 11b allows the corresponding second sub-winding needle 21 to pass through.

[0089] Optionally, for a single second winding needle 2, two second sub-winding needles 21 may be configured to move synchronously so that the distance between each second sub-winding needle 21 and the corresponding first sub-winding needle 11 in the second direction changes synchronously; but the present invention is not limited thereto.

[0090] Of course, the structure of the second winding needle 2 is not limited to this; in other embodiments of the present application, the second winding needle 2 can also be constructed as a winding needle block, and a penetration channel can be formed between the second winding needle 2 and the first winding needle 1 to realize the penetration of the coil 30 and facilitate the fixation of the coil 30.

[0091] Please refer to Figures 2 and 4. In some embodiments, a side wall of at least one first sub-winding needle 11 facing another first sub-winding needle 11 is formed with an avoidance opening 11c, and the avoidance opening 11c is respectively connected to the accommodating cavity 11a and the corresponding two matching openings 11b, so as to be suitable for avoiding the corresponding second sub-winding needle 21. For a single first sub-winding needle 11 formed with the avoidance opening 11c, its avoidance opening 11c is respectively connected to its accommodating cavity 11a and the two matching openings 11b thereon.

[0092] It can be seen that the avoidance opening 11c can also provide avoidance for the switching movement of the winding needle assembly 10 between the first state and the second state, which is conducive to further expanding the movement space provided for the second winding needle 2 when the winding needle assembly 10 switches between the first state and the second state.

[0093] Furthermore, the provision of the avoidance opening 11c prevents the sidewall of the first winding needle 11 facing the other first winding needle 11 from interfering with the movement of the second winding needle 21. This allows the spacing between the two second winding needles 21 to be appropriately reduced in the first direction, thereby increasing the proportion of the outer peripheral wall of the second winding needle 21 within the predetermined cylindrical surface of the winding needle assembly 10. This increases the circumferential support range of the outer peripheral wall of the second winding needle 2 for the web 30 in the first state, thereby improving the winding reliability of the winding needle assembly 10 for the web 30. For example, when the second winding needle 2 is configured to be movable relative to the first winding needle 1 in the second direction to switch the winding needle assembly 10 between the first and second states, the avoidance opening 11c does not obstruct the movement of the corresponding second winding needle 21. In the first state, the spacing between the two second winding needles 21 can be appropriately reduced, for example, by appropriately increasing the width of at least one second winding needle 21 in the first direction. This increases the circumferential support range of the second winding needle 2 for the web 30 while also enhancing the structural strength of the second winding needle 21.

[0094] In the above technical solution, by setting the avoidance opening 11c, an avoidance can be provided for the switching movement of the winding needle assembly 10 between the first state and the second state, which is beneficial to further expand the movement space provided for the second winding needle 2 when the winding needle assembly 10 switches between the first state and the second state. To a certain extent, the distance between the two second sub-winding needles 21 in the first direction can be appropriately reduced to adapt to the increase in the proportion of the outer peripheral wall of the second sub-winding needle 21 in the preset cylindrical surface in the circumferential direction of the winding needle assembly 10, thereby increasing the circumferential support range of the outer peripheral wall of the second winding needle 2 on the coil 30 in the first state.

[0095] It is understandable that in the above technical solution, the provision of the avoidance opening 11c can appropriately reduce the spacing between the two second sub-winding needles 21 in the first direction to a certain extent, and this is applicable to both of the following structural types: Type 1: In the second state, at least a portion of one of the second sub-winding needles 21 extends into one of the first sub-winding needles 11, and at least a portion of the other second sub-winding needle 21 extends into the other first sub-winding needle 11; Type 2: In the second state, at least a portion of one of the second sub-winding needles 21 extends into one of the first sub-winding needles 11, and at least a portion of the other second sub-winding needle 21 extends into both the one first sub-winding needle 11 and the other first sub-winding needle 11. In other words, the provision of the avoidance opening 11c ensures that the spacing between the two second sub-winding needles 21 in the first direction is not restricted by the spacing between the two first sub-winding needles 11 in the first direction.

[0096] Exemplarily, the first direction is the left-right direction, and the second direction is the up-down direction. A side wall of each first sub-winding needle 11 facing the other first sub-winding needle 11 is formed with an avoidance opening 11c. In the first state, the right end of the second sub-winding needle 21 on the left is flush with the right end of the corresponding first sub-winding needle 11, and the left end of the second sub-winding needle 21 on the right is flush with the left end of the corresponding first sub-winding needle 11. In the second state, at least a portion of the second sub-winding needle 21 on the left is suitable for extending into the left accommodating cavity 11a through the corresponding matching opening 11b and the corresponding avoidance opening 11c, and at least a portion of the second sub-winding needle 21 on the right is suitable for extending into the right accommodating cavity 11a through the corresponding matching opening 11b and the corresponding avoidance opening 11c.

[0097] Please refer to Figure 4. In some embodiments, a partition 3 is provided in the accommodating chamber 11a. The partition 3 is respectively connected to the opposite side walls of the accommodating chamber 11a to divide the accommodating chamber 11a into two chambers 11f arranged in sequence along the second direction. The two chambers 11f respectively correspond to the two second winding needles 2. One of the chambers 11f is used to accommodate a portion of one of the second winding needles 2, and the other chamber 11f is used to accommodate a portion of the other second winding needle 2. At the same time, the partition 3 can play a certain supporting role on the opposite side walls of the accommodating chamber 11a, thereby improving the structural stability of the accommodating chamber 11a and improving the structural reliability of the winding needle assembly 10.

[0098] In the above technical solution, a partition 3 is provided in the accommodating cavity 11a to divide the accommodating cavity 11a into two chambers 11f, thereby improving the structural stability of the accommodating cavity 11a and the structural reliability of the needle winding assembly 10 while meeting the accommodating requirements of the second needle winding 2 in the second state.

[0099] It can be understood that the relationship between the depth h1 of the chamber 11f in the second direction and the width h2 of the second winding needle 2 in the second direction can be set according to actual needs; for example, h1≥h2, so that the second winding needle 2 can be fully extended into the first winding needle 1 in the second direction; of course, h1 can also be smaller than h2.

[0100] Optionally, the separator 3 and the first sub-winding needle 11 are an integral part; or, the separator 3 and the first sub-winding needle 11 are separate parts, in which case the separator 3 can be fixed to the first sub-winding needle 11 by assembly and fixing means.

[0101] Optionally, a side wall of at least one first sub-winding needle 11 facing another first sub-winding needle 11 is formed with an escape opening 11c, which is connected to the accommodating cavity 11a and the two corresponding mating openings 11b, respectively, to accommodate the second sub-winding needle 21. Furthermore, a partition 3 is provided within the first sub-winding needle 11 having the escape opening 11c. The partition 3 separates the accommodating cavity 11a of the first sub-winding needle 11 into two chambers 11f arranged sequentially along the second direction. The partition 3 can extend to the escape opening 11c to divide the escape opening 11c into two sub-openings, or the partition 3 can extend to a position spaced apart from the escape opening 11c.

[0102] Of course, the embodiments of the present application are not limited thereto; in other embodiments, the partition 3 may not be provided in the accommodating cavity 11 a , and in this case, the first sub-winding needle 11 may be substantially hollow in structure.

[0103] Referring to FIG. 3 , in some embodiments, the winding needle assembly 10 has a center line L2 extending along the second direction.

[0104] Among them, the two first sub-winding needles 11 are respectively arranged on both sides of the center line L2 in the first direction; and / or, the two second sub-winding needles 21 of at least one second winding needle 2 are respectively arranged on both sides of the center line L2 in the first direction.

[0105] In the above technical solution, by arranging two first sub-winding needles 11 respectively on both sides of the center line L2 in the first direction, and / or the two second sub-winding needles 21 of the second winding needle 2 respectively on both sides of the center line L2 in the first direction, the spacing area between the two first sub-winding needles 11 and the spacing area between the two second sub-winding needles 21 of the second winding needle 2 can be arranged relative to or staggered, so that the coil 30 can be passed through the spacing area between the two second sub-winding needles 21 to the spacing area between the two first sub-winding needles 11, which is convenient for subsequent clamping or subsequent continued threading.

[0106] In addition, in the above technical solution, the two first sub-winding needles 11 can move relative to each other. If the two first sub-winding needles 11 are configured to clamp the coil 30, the coil 30 can pass through the space area between the two second sub-winding needles 21 to the space area between the two first sub-winding needles 11, so as to achieve clamping and release of the coil 30 through the two first sub-winding needles 11.

[0107] For example, taking the first direction as the left-right direction and the second direction as the up-down direction as an example, the above technical solution includes the following examples:

[0108] Example 1: The two first sub-winding needles 11 are respectively arranged on the left and right sides of the center line L2, that is, one of the first sub-winding needles 11 is arranged on the left side of the center line L2, and the other first sub-winding needle 11 is arranged on the right side of the center line L2. The two second sub-winding needles 21 of at least one second winding needle 2 are respectively arranged on the left and right sides of the center line L2, that is, in the same second winding needle 2, one of the second sub-winding needles 21 is arranged on the left side of the center line L2, and the other second sub-winding needle 21 is arranged on the right side of the center line L2; at this time, the spacing area between the two first sub-winding needles 11 can be arranged relative to the spacing area between the two second sub-winding needles 21 of the second winding needle 2.

[0109] Furthermore, in Example 1, the two first sub-winding needles 11 are symmetrically arranged about the center line L2, and / or the two second sub-winding needles 21 of at least one second winder needle 2 are symmetrically arranged about the center line L2.

[0110] Example 2: The two first sub-winding needles 11 are respectively arranged on the left and right sides of the center line L2, that is, one of the first sub-winding needles 11 is arranged on the left side of the center line L2, and the other first sub-winding needle 11 is arranged on the right side of the center line L2. One of the two second sub-winding needles 21 of the second winding needle 2 is arranged on the left or right side of the center line L2, and a part of the other one is arranged on the left side of the center line L2, and the other part of the other one is arranged on the right side of the center line L2; at this time, the spacing area between the two first sub-winding needles 11 can be staggered left and right with the spacing area between the two second sub-winding needles 21 of the second winding needle 2, and the staggered distance can be set according to actual needs.

[0111] Among them, in Example 2, the setting forms of the two second winding needles 2 can be the same or different; for example, one of the second sub-winding needles 21 in the upper second winding needles 2 is arranged on the left side of the center line L2, and a part of the other second sub-winding needle 21 is arranged on the left side of the center line L2, and the other part is arranged on the right side of the center line L2, while one of the second sub-winding needles 21 in the lower second winding needles 2 is arranged on the left side of the center line L2, a part of the other second sub-winding needle 21 is arranged on the left side of the center line L2, and the other part is arranged on the right side of the center line L2, or one of the second sub-winding needles 21 in the lower second winding needles 2 is arranged on the right side of the center line L2, and a part of the other second sub-winding needle 21 is arranged on the left side of the center line L2, and the other part is arranged on the right side of the center line L2.

[0112] Furthermore, in Example 2, the two first sub-winding needles 11 are symmetrically arranged about the center line L2.

[0113] Example three: The two second sub-winding needles 21 of at least one second winding needle 2 are respectively arranged on the left and right sides of the center line L2, that is, in the same second winding needle 2, one of the second sub-winding needles 21 is arranged on the left side of the center line L2, and the other second sub-winding needle 21 is arranged on the right side of the center line L2, one of the first sub-winding needles 11 is arranged on the left or right side of the center line L2, and a part of the other first sub-winding needle 11 is arranged on the left side of the center line L2, and the other part is arranged on the right side of the center line L2; at this time, the spacing area between the two first sub-winding needles 11 can be staggered left and right with the spacing area between the two second sub-winding needles 21 of the second winding needle 2, and the staggered distance can be set according to actual needs.

[0114] Furthermore, in Example 3, the two second sub-winding needles 21 of at least one second winding needle 2 are symmetrically arranged about the center line L2.

[0115] Referring to Figures 1-4, in some embodiments, the winding needle assembly 10 further includes two opposing clamping members 4 that can move relative to each other to clamp the material coil 30, thereby securing the material coil 30 and enabling the winding needle assembly 10 to rotate so that the material coil 30 is wound around the outer peripheral wall of the winding needle assembly 10. As can be seen, while the winding needle assembly 10 is winding the material coil 30, a portion of the material coil 30 can pass between the two clamping members 4. After the clamping members 4 clamp the material coil 30, the winding needle assembly 10 begins to rotate to wind the material coil 30, thereby reducing the risk of the material coil 30 becoming loose or wrinkled during the winding process and improving the safety of the structure after the material coil 30 is formed.

[0116] As shown in Figures 1-4, two clamping members 4 are respectively provided on two first sub-winding needles 11. Thus, each clamping member 4 is provided on a corresponding first sub-winding needle 11, and the two clamping members 4 can move closer to or further away from each other to clamp and release the web 30. For example, one clamping member 4 is fixedly provided on one of the first sub-winding needles 11, and the other clamping member 4 is movably provided on the other first sub-winding needle 11, so that the two clamping members 4 can move closer to or further away from each other; alternatively, each clamping member 4 can be movably provided on a corresponding first sub-winding needle 11.

[0117] In the above technical solution, a clamping member 4 is provided so that the coil 30 can be clamped by the clamping member 4 to fix the coil 30, thereby realizing the winding of the coil 30 on the outer peripheral wall of the winding needle assembly 10; in addition, due to the provision of the clamping member 4, the position of the first sub-winding needle 11 does not need to be changed when the coil 30 is clamped and fixed, that is, the position of the first sub-winding needle 11 is relatively fixed, which facilitates the relative fixation of the preset cylindrical surface in the first state and the second state, thereby helping to reduce the position requirements for the second winding needle 2 in the first state and the second state, and during the winding process, there is no need to adjust the position of the first sub-winding needle 11, which helps to simplify the winding steps of the winding needle assembly 10.

[0118] Please refer to Figures 3 and 4. In some embodiments, the outer peripheral walls of the two first sub-winding needles 11 are arranged back to back, and a mounting groove 11d is formed on the side wall of each first sub-winding needle 11 facing the other first sub-winding needle 11, and at least a portion of each clamping member 4 is accommodated in the mounting groove 11d of the corresponding first sub-winding needle 11; it can be seen that the mounting groove 11d can provide an installation space for the clamping member 4, so as to reduce the influence of the clamping member 4 on the distance between the two first sub-winding needles 11, improve the winding effect, and at the same time help to appropriately reduce the outer contour size of the winding needle assembly 10 and reduce the space occupied by the winding needle assembly 10.

[0119] In some other embodiments, the second winding needle 2 includes two second sub-winding needles 21 spaced apart along the first direction, and each clamping member 4 is respectively provided on the two second sub-winding needles 21; for example, one of the clamping members 4 is fixedly provided on one of the second sub-winding needles 21, and the other clamping member 4 is movably provided on the other second sub-winding needle 21 to achieve the approach or distance between the two clamping members 4; or, each clamping member 4 is respectively movably provided on the corresponding second sub-winding needle 21.

[0120] Of course, in other embodiments of the present application, the winding needle assembly 10 may not be provided with the clamping member 4, in which case the two first sub-winding needles 11 can clamp and fix the coil 30; or, when the second winding needle 2 includes two second sub-winding needles 21 spaced apart along the first direction, the spacing between the two second sub-winding needles 21 in the first direction is adjustable so that the two second sub-winding needles 21 can clamp and fix the coil 30; or, a clamping assembly independent of the winding needle assembly 10 may be provided separately.

[0121] Please refer to Figures 2 to 4. In some embodiments, the outer peripheral walls of the two first sub-winding needles 11 are arranged back to back, and the outer peripheral wall of each first sub-winding needle 11 is respectively formed with a groove 11e. The grooves 11e of the two first sub-winding needles 11 are arranged back to back along the radial direction of the winding needle assembly 10, that is, the notches of the two grooves 11e are arranged back to back.

[0122] It can be seen that the groove 11e can provide a clamping space for the blanking component 20, so that the blanking component 20 can clamp the wound coil 30, realize the separation of the coil 30 from the winding needle component 10, and complete the needle withdrawal operation. Exemplarily, the blanking component 20 includes an inner clamping needle 6 and an outer clamping needle 7, the inner clamping needle 6 is used to be inserted into the groove 11e so that a part of the inner clamping needle 6 is matched with the radial inner side of the winding, and the outer clamping needle 7 is suitable for moving to the radial outer side of the coil 30, and the outer clamping needle 7 moves relative to the inner clamping needle 6 to clamp the coil 30; when the coil 30 needs to be removed from the winding needle component 10, the inner clamping needle 6 of one blanking component 20 is inserted into the groove 11e, the outer clamping needle 7 is moved to the outer side of the coil 30, and the inner clamping needle of the other blanking component 20 is inserted into the groove 11e. 6 is inserted into another groove 11e, and the outer clamping needle 7 is also moved to the outside of the coil 30. The corresponding outer clamping needle 7 and inner clamping needle 6 are close to each other to clamp the coil 30 from the inside and outside. At this time, the outer clamping needle 7 and the inner clamping needle 6 can pull the coil 30 to remove the coil 30 from the winding needle assembly 10. The two blanking assemblies 20 both apply force to the coil 30, and the two blanking assemblies 20 are arranged relative to each other along the radial direction of the coil 30, so that the two blanking assemblies 20 can apply force to the coil 30 more evenly, which can reduce the risk of deformation of the coil 30.

[0123] After the blanking assembly 20 takes off the coil 30 , the two blanking assemblies 20 can be moved away from each other to stretch the coil 30 so that the coil 30 is further flattened.

[0124] In the above technical solution, grooves 11e are respectively provided on the outer peripheral wall of each first sub-winding needle 11 to provide a mating space with the blanking assembly 20, so as to realize the separation of the coil 30 and the winding needle assembly 10 and proceed to the next process; at the same time, since the two grooves 11e are arranged radially opposite to each other along the radial direction of the winding needle assembly 10, the two blanking assemblies 20 can be arranged radially opposite to each other, which is convenient for directly stretching the coil 30 after removing it to further flatten it, and the coil 30 is subjected to a more balanced force, reducing the risk of deformation of the coil 30.

[0125] Optionally, the first winding needle 1 and the second winding needle 2 may be made of aluminum alloy or alloy steel.

[0126] Please refer to Figures 1 to 4. In some embodiments, the second winding needle 2 moves within the cross-section of the winding needle assembly 10 to switch the winding needle assembly 10 between the first state and the second state. During the switching of the winding needle assembly 10 between the first state and the second state, the axial position of the second winding needle 2 in the winding needle assembly 10 can remain unchanged.

[0127] For example, the second winding needle 2 can move and / or rotate within the cross section of the winding needle assembly 10 .

[0128] In the above technical solution, by setting the second winding needle 2 to move within the cross-section of the winding needle assembly 10 so that the winding needle assembly 10 switches between the first state and the second state, the movement space required for the second winding needle 2 when switching between the above states can be reduced, saving the space required for the winding needle assembly 10 to work.

[0129] Please refer to FIG. 1 to FIG. 4 . In some embodiments, at least one second winding needle 2 is movable relative to the first winding needle 1 along a second direction.

[0130] In the above technical solution, by setting at least one second winding needle 2 to be movable relative to the first winding needle 1 along the second direction, it is beneficial to simplify the movement mode of the at least one second winding needle 2, and at the same time, it can further reduce the movement space required for the at least one second winding needle 2 during the switching of the winding needle assembly 10 between the first state and the second state.

[0131] For example, as shown in Figures 1-4, each second winding needle 2 can move relative to the first winding needle 1 in the second direction to change the position of the second winding needle 2 relative to the first winding needle 1 in the second direction, thereby changing the width of the winding needle assembly 10 in the second direction and switching between different states of the winding needle assembly 10. Optionally, the two second winding needles 2 can be configured to move synchronously in the second direction to achieve synchronous switching of the two second winding needles 2, which is beneficial for improving winding efficiency.

[0132] Exemplarily, if the winding needle assembly 10 is constructed such that in the first state the second winding needle 2 is located outside the first sub-winding needle 11, and in the second state at least part of the second winding needle 2 extends into the corresponding first sub-winding needle 11, then when at least one second winding needle 2 can be moved relative to the first winding needle 1 along the second direction, the length of the at least one second winding needle 2 extending into the first winding needle 1 in the second direction can be adjusted, thereby adjusting the width of the winding needle assembly 10 in the second direction.

[0133] Please refer to Figures 1 to 4. In some embodiments, there are multiple second states, and the multiple second states are respectively from the first gear to the Nth gear. From the first gear to the Nth gear, the width of the winding needle assembly 10 in the second direction decreases; in the first gear, the width of the winding needle assembly 10 in the second direction is W1, and in the Mth gear, the width of the winding needle assembly 10 in the second direction is W M , 1≤M≤N, in the Nth gear, the width of the winding needle assembly 10 in the second direction is W N , N≥2, then W1>W M >W N That is, the higher the gear position, the smaller the width of the winding needle assembly 10 in the second direction. In the first state, the width of the winding needle assembly 10 in the second direction is W, and W>W1.

[0134] It can be seen that, through the above arrangement, the winding needle assembly 10 can stretch the coil 30 at least once before the coil 30 is removed; for example, if the winding needle assembly 10 stretches the coil 30 once before removing the coil 30, the winding needle assembly 10 can stretch the coil 30 using any gear, such as the winding needle assembly 10 can stretch the coil 30 using the Nth gear; for another example, if the winding needle assembly 10 stretches the coil 30 multiple times before removing the coil 30, the winding needle assembly 10 can stretch the coil 30 using any two gears, and the gear corresponding to the previous stretching is lower than the gear corresponding to the next stretching, and the shape of the coil 30 after stretching at the high gear is flatter than the shape of the coil 30 after stretching at the low gear, and the gear difference corresponding to the two adjacent stretchings can be greater than or equal to 1.

[0135] In the above technical solution, multiple second states are set from the first gear to the Nth gear, and from the first gear to the Nth gear, the width of the winding needle assembly 10 in the second direction is reduced, so as to improve the shape stability of the coil 30 after it is removed from the winding needle assembly 10, while adapting to the different requirements of different coils 30 for the number of stretching times, flatness, etc.

[0136] Optionally, in the Nth gear, the second winding needle 2 does not protrude beyond the corresponding side wall of the first winding needle 1 in the second direction; for example, with the second direction being the up-down direction, for the upper second winding needle 2, in the Nth gear, the upper end surface of the upper second winding needle 2 is located below the upper side wall of the first winding needle 1, or the upper end surface of the upper second winding needle 2 is flush with the upper side wall of the first winding needle 1; for the lower second winding needle 2, in the Nth gear, the lower end surface of the lower second winding needle 2 is located above the lower side wall of the first winding needle 1, or the lower end surface of the lower second winding needle 2 is flush with the lower side wall of the first winding needle 1. Of course, in other examples, the second state is one, and in the second state, the second winding needle 2 does not protrude beyond the corresponding side wall of the first winding needle 1 in the second direction.

[0137] On the second aspect, an embodiment of the present application provides a winding device, including the above-mentioned winding needle assembly 10, a first driving mechanism and a second driving mechanism. The first driving mechanism is used to drive the winding needle assembly 10 to rotate around the central axis L1 of the winding needle assembly 10 to achieve winding of the roll 30, and the second driving mechanism is used to drive at least one first sub-winding needle 11 to move along the first direction to achieve relative movement of the two first sub-winding needles 11 in the first direction.

[0138] In the above technical solution, since the winding device adopts the above-mentioned winding needle assembly 10, and the winding needle assembly 10 can improve the ability of the coil 30 to maintain its own shape and shape stability after the coil 30 is removed from the winding needle assembly 10, the winding device can reduce the probability of the coil collapsing and improve the reliability of the coil; if the coil 30 is an electrode assembly, it can improve reliability problems such as diaphragm folding and electrode wrinkling, thereby improving the safety of the electrode assembly.

[0139] 1 and 3 , each second winding needle 2 can move relative to the first sub-winding needle 11 along the second direction to achieve switching of the winding needle assembly 10 between the first state and the second state.

[0140] In the first state, the second winding needle 2 is located outside the first sub-winding needle 11; the winding device also includes a third driving mechanism, which can be used to drive the second winding needle 2 to move relative to the first winding needle 1 along the second direction to switch the winding needle assembly 10 between the first state and the second state.

[0141] Exemplarily, the second winding needle 2 includes two second sub-winding needles 21 , and the third driving mechanism is used to drive the two second sub-winding needles 21 corresponding to the second winding needle 2 to move relative to the first winding needle 1 along the second direction.

[0142] In the above technical solution, the movement mode of the second winding needle 2 is simple, which can further reduce the movement space required by the second winding needle 2 during the switching of the winding needle assembly 10 between the first state and the second state.

[0143] In some embodiments, the winding needle assembly 10 includes two clamping members 4 that are arranged opposite to each other and can move relative to each other. The winding device may include a fourth driving mechanism, which is used to drive at least one clamping member 4 to move to achieve the clamping and release of the coil 30 by the two clamping members 4.

[0144] Thirdly, embodiments of the present application provide a winding method for winding an electrode assembly using a winding needle assembly 10. The winding needle assembly 10 includes a first winding needle 1 and a second winding needle. The first winding needle 1 includes two first sub-winding needles 11 arranged opposite each other in a first direction and capable of relative movement in the first direction. A second winding needle 2 is provided on either side of the first winding needle 1 in a second direction. The winding needle assembly 10 is configured to switch between a first state and a second state. In the first state, the outer peripheral wall of the second winding needle 2 and the outer peripheral wall of the first sub-winding needle 11 are located on the same predetermined cylindrical surface. In the second state, the second winding needle 2 is located inside the predetermined cylindrical surface, such that the width of the winding needle assembly 10 in the second direction in the second state is smaller than the width of the winding needle assembly 10 in the first state. The first and second directions are perpendicular to the axial direction of the winding needle assembly 10.

[0145] Each first winding needle 11 has a housing cavity 11a formed therein. The housing cavity 11a extends through both side walls of the first winding needle 11 in the second direction to form respective mating openings 11b. Thus, the side wall of each first winding needle 11 facing one of the second winding needles 2 is formed with a mating opening 11b, and the side wall of each first winding needle 11 facing the other second winding needle 2 is also formed with a mating opening 11b. Each second winding needle 2 is movable relative to the first winding needle 11 to switch the winding needle assembly 10 between a first state and a second state. In the second state, the second winding needle 2 is located inside the predetermined cylindrical surface, and at least a portion of the second winding needle 2 extends into the housing cavity 11a through the corresponding mating opening 11b. In the second state, a portion of the second winding needle 2 extends into the corresponding first winding needle 11, while another portion is located outside the first winding needle 11, or the entire second winding needle 2 extends into the corresponding first winding needle 11.

[0146] Please refer to Figures 6 to 8, Figure 6 is a schematic diagram of the winding needle assembly 10 shown in Figure 1 winding the coil, Figure 7 is a schematic diagram of the blanking assembly 20 stretching the coil provided in some embodiments of the present application, and Figure 8 is a flow chart of the winding method provided in some embodiments of the present application; the winding method includes: the winding needle assembly 10 winds the coil 30 in a first state until a preset condition is met, the winding needle assembly 10 stretches the coil 30 at least once, and during the stretching process, the winding needle assembly 10 switches to the second state and increases the distance between the two first sub-winding needles 11 in the first direction.

[0147] Increasing the distance between the two first sub-winding needles 11 in the first direction can be achieved, for example, by moving the two first sub-winding needles 11 in opposite directions, or by moving one of the first sub-winding needles 11 along the first direction away from the other first sub-winding needle 11.

[0148] It is understood that during the stretching process, the order of "switching the winding needle assembly 10 to the second state" and "increasing the distance between the two first sub-winding needles 11 in the first direction" can be adapted and coordinated; for example, the winding needle assembly 10 can be switched to the second state first, and then the distance between the two first sub-winding needles 11 in the first direction can be increased, or the two operations can be performed simultaneously, that is, the distance between the two first sub-winding needles 11 in the first direction is increased while the winding needle assembly 10 is switched to the second state. Furthermore, when the two operations are performed simultaneously, the rate of increase in the distance between the two first sub-winding needles 11 in the first direction can be matched to the degree to which the winding needle assembly 10 is switched to the second state, so that during the stretching process, the outer peripheral wall of the second winding needle 2 can still consistently support the corresponding portion of the coil 30, thereby further reducing the probability of the coil 30 collapsing.

[0149] It can be seen that before the coil 30 is removed from the winding needle assembly 10, the winding needle assembly 10 can stretch the coil 30 at least once, so that the shape of the coil 30 tends to be flat, thereby effectively reducing the suspended height of the unsupported part of the coil 30 when the coil 30 is removed from the winding needle assembly 10, especially reducing the suspended height of the upper part of the coil 30 when the coil 30 is removed from the winding needle assembly 10, reducing the risk of collapse of the above-mentioned part of the coil 30, improving the stability of the shape of the coil 30 when it is removed, facilitating subsequent shaping processes, and at the same time helping to reduce problems such as diaphragm folding and electrode wrinkling caused by collapse of the coil 30, thereby improving the reliability and safety of the use of the coil 30.

[0150] For example, take the example of the winding needle assembly 10 stretching the coil 30 once: the winding needle assembly 10 is in the first state and rotates to wind the coil 30 until the preset conditions are met, the winding needle assembly 10 stops rotating, and the winding needle assembly 10 switches to the second state, so that the width of the winding needle assembly 10 in the second direction in the second state is smaller than the width of the winding needle assembly 10 in the second direction in the first state, and the distance between the two first sub-winding needles 11 in the first direction is increased, so that the width of the coil 30 in the second direction gradually decreases and the width of the coil 30 in the first direction gradually increases, and the coil 30 tends to be flat.

[0151] For another example, take the winding needle assembly 10 performing two stretching operations on the web 30: the multiple second states can be a first gear and a second gear, respectively. From the first gear to the second gear, the width of the winding needle assembly 10 in the second direction decreases. The winding needle assembly 10 is in the first state and rotates to wind the web 30 until a preset condition is met. The winding needle assembly 10 stops rotating and switches to the first gear, increasing the distance between the two first sub-winding needles 11 in the first direction, causing the web 30 to flatten. After the first stretching is completed, a second stretching operation can be performed, switching the winding needle assembly 10 to the second gear, further increasing the distance between the two first sub-winding needles 11 in the first direction, causing the web 30 to flatten further. Of course, the winding needle assembly 10 can also stretch the web 30 three or more times.

[0152] In the above technical solution, the winding needle assembly 10 stretches the coil 30 at least once before removing the coil from the winding needle assembly 10, which can improve the ability of the coil 30 to maintain its own shape and shape stability after the coil 30 is removed from the winding needle assembly 10. Therefore, the winding method can reduce the probability of collapse of the coil 30 and improve the reliability of the use of the coil 30; if the coil 30 is an electrode assembly, it can improve reliability problems such as folding of the diaphragm and wrinkling of the electrode, thereby improving the safety of the electrode assembly.

[0153] In the embodiment of the present application, there is no specific limitation on the preset condition. For example, the preset condition may be that the length of the wound coil 30 meets the preset length, or the thickness of the wound coil 30 meets the preset thickness, etc.

[0154] Please refer to FIG. 6 and FIG. 7 . In some embodiments, the winding device further includes a blanking assembly 20 . The blanking assembly 20 is used to remove the coil 30 from the winding needle assembly 10 .

[0155] The winding method also includes: after the blanking assembly 20 removes the coil 30, the blanking assembly 20 stretches the coil 30. The change in the shape of the coil 30 caused by the stretching process will not be restricted by the size of the first winding needle 1 in the second direction, so that the coil 30 becomes further flat, which is conducive to reducing the thickness of the electrode assembly and the thickness of the battery cell.

[0156] For example, the blanking component 20 includes an inner clamping needle 6 and an outer clamping needle 7. The inner clamping needle 6 is arranged inside the coil 30, and the outer clamping needle 7 moves to the outside of the coil 30. The inner clamping needle 6 and the outer clamping needle 7 clamp the coil 30 and pull out the coil needle component 10 to realize needle withdrawal; then the two blanking components 20 move away from each other to stretch the coil 30.

[0157] Please refer to Figures 1 to 8 again to describe the winding needle assembly 10 of a specific embodiment of the present application.

[0158] In the embodiment of the present application, the needle winding assembly 10 includes a first needle 1, a second needle 2 and a clamping member 4. The needle winding assembly 10 has a central axis L1 and a center line L2. The central axis L1 extends axially along the needle winding assembly 10, and the center line L2 extends in the vertical direction.

[0159] The first winding needle 1 includes two first sub-winding needles 11 arranged opposite each other in the left-right direction. The two first sub-winding needles 11 are respectively located on the left and right sides of the centerline L2. The two first sub-winding needles 11 can move relative to each other in the first direction to change the distance between the two first sub-winding needles 11 in the first direction. A mounting groove 11d is formed on the side wall of each first sub-winding needle 11 facing the other first sub-winding needle 11, and a groove 11e is formed on the outer peripheral wall of each first sub-winding needle 11 facing away from the other first sub-winding needle 11. The grooves 11e of the two first sub-winding needles 11 are arranged in opposite directions along the radial direction of the winding needle assembly 10 to provide space for the inner clamping needle 6 of the blanking assembly 20 to mate, facilitating the blanking assembly 20 to remove the coil from the winding needle assembly 10.

[0160] Among them, an accommodating cavity 11a is formed in each first sub-winding needle 11, and the accommodating cavity 11a passes through the upper and lower side walls of the first sub-winding needle 11 to form a matching opening 11b respectively, and the accommodating cavity 11a passes through the side wall of the corresponding first sub-winding needle 11 facing the other first sub-winding needle 11 to form an avoidance opening 11c, and the avoidance opening 11c is connected to the matching opening 11b.

[0161] The first winding needle 1 is provided with a second winding needle 2 on both sides in the up and down directions, and each second winding needle 2 includes two second sub-winding needles 21 arranged at intervals along the left and right directions. The two second sub-winding needles 21 are respectively arranged on the left and right sides of the center line L2, so that the spacing area between the two second sub-winding needles 21 is directly opposite to the spacing area between the two first sub-winding needles 11 in the upper and lower directions; each second sub-winding needle 21 can move relative to the first sub-winding needle 11 in the cross-section of the winding needle assembly 10 and in the upper and lower directions, so that the winding needle assembly 10 has a first state and a second state that can be switched with each other. In the first state, the outer peripheral wall of each second sub-winding needle 21 and the outer peripheral wall of each first sub-winding needle 11 are on the same preset cylindrical surface, and each second sub-winding needle 21 is located outside the first sub-winding needle 11; in the second state, at least part of each second sub-winding needle 21 extends into the accommodating cavity 11a of the corresponding first sub-winding needle 11 through the corresponding matching opening 11b and the avoidance opening 11c, and each second sub-winding needle 21 is located on the inner side of the preset cylindrical surface, so that the width of the winding needle assembly 10 in the up and down direction in the second state is smaller than the width of the winding needle assembly 10 in the up and down direction in the first state.

[0162] The preset cylindrical surface is a cylindrical surface, and the outer peripheral wall of each second sub-winding needle 21 and the outer peripheral wall of each first sub-winding needle 11 are arc surfaces.

[0163] There are two clamping members 4 and the two clamping members 4 are arranged in sequence along the left and right directions. Each clamping member 4 is arranged in a corresponding mounting groove 11d. The two clamping members 4 can move relative to each other to clamp the coil 30. The coil 30 can then pass through the gap between the two second sub-winding needles 21 to the gap between the two first sub-winding needles 11 and be clamped by the clamping member 4.

[0164] The winding needle assembly 10 winds the electrode assembly, and the coil 30 passes through the space area between the two second sub-winding needles 21 and is arranged between the two first sub-winding needles 11 and is clamped by the two clamping members 4. The winding needle assembly 10 switches to the first state (if the winding needle assembly 10 is in the first state, there is no need to switch, if the winding needle assembly 10 is not in the first state, it is switched), and the winding needle assembly 10 rotates around its central axis L1 to achieve winding of the coil 30; for example, the diaphragm passes through the space area between the two second sub-winding needles 21 and is arranged between the two first sub-winding needles 11 and is clamped by the two clamping members 4, and then the electrode sheet is fed in, and the winding needle assembly 10 rotates to allow the diaphragm and the electrode sheet to be wound on a preset cylindrical surface.

[0165] After the coil 30 is wound to a certain length, the winding needle assembly 10 stops rotating, and each second winding needle 2 moves in the up and down direction toward the direction close to the first winding needle 1 to switch the winding needle assembly 10 to the second state, reducing the width of the winding needle assembly 10 in the up and down direction. At this time, each second sub-winding needle 21 is respectively accommodated in the accommodating cavity 11a of the corresponding first sub-winding needle 11 through the corresponding matching port 11b and the corresponding avoidance port 11c. At the same time, the two first sub-winding needles 11 are separated in the left and right directions to stretch the coil 30, so as to achieve the "first flattening" of the coil 30, so that the upper part of the coil 30 basically stops against the upper side wall of the first winding needle 1, and the lower part of the coil 30 basically stops against the lower side wall of the first winding needle 1.

[0166] Then, the inner clamping needles 6 of the two blanking assemblies 20 respectively cooperate with the grooves 11e of the two first sub-winding needles 11, and the outer clamping needles 7 respectively move to the outside of the coil 30, and the outer clamping needles 7 and the corresponding inner clamping needles 6 clamp the coil 30, and pull out the winding needle assembly 10 to achieve the separation of the winding needle assembly 10 and the coil 30; then, the two blanking assemblies 20 move away from each other to achieve the "second flattening" of the coil 30. At the same time, in the above process, the winding needle assembly 10 can be restored to the initial winding state to wait for the next winding.

[0167] In the above technical solution, before the coil 30 is removed from the winding needle assembly 10, the winding needle assembly 10 can stretch the coil 30 once to reduce the suspended height of the upper part of the coil 30 when the winding needle assembly 10 is pulled out from the coil 30, reduce the risk of collapse of the upper part of the coil 30, and at the same time reduce the risk of reliability problems such as wrinkling and breakage of the pole piece caused by the collapse of the coil 30, facilitate the subsequent shaping of the coil 30, and improve the reliability and safety of the use of the coil 30.

[0168] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0169] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A needle winding assembly, wherein: include: A first winding needle, the first winding needle comprises two first sub-winding needles which are arranged opposite to each other in a first direction and can move relative to each other in the first direction, each of the first sub-winding needles has a receiving cavity formed therein, and the receiving cavity penetrates two side walls of the first sub-winding needle in the second direction to form matching openings respectively; A second winding needle, wherein the second winding needles are respectively arranged on both sides of the first winding needle along the second direction, each of the second winding needles can move relative to the first sub-winding needle, and the winding needle assembly is configured to be switchable between a first state and a second state, In the first state, the outer peripheral wall of the second winding needle and the outer peripheral wall of the first sub-winding needle are on the same preset cylindrical surface; in the second state, the second winding needle is located on the inner side of the preset cylindrical surface and at least a portion of the second winding needle extends into the accommodating cavity through the corresponding matching opening, so that the width of the winding needle assembly in the second direction in the second state is smaller than the width of the winding needle assembly in the second direction in the first state, and the first direction and the second direction are perpendicular to the axial direction of the winding needle assembly.

2. The needle winding assembly according to claim 1, wherein: In the first state, the second winding needle is located outside the first sub-winding needle.

3. The needle winding assembly according to claim 1 or 2, wherein: At least one of the second winding needles includes two second sub-winding needles spaced apart along the first direction, In the first state, the outer peripheral wall of the second sub-winding needle and the outer peripheral wall of the first sub-winding needle are both on the preset cylindrical surface; in the second state, at least part of the second sub-winding needle extends into the corresponding accommodating cavity so that the second sub-winding needle is located on the inner side of the preset cylindrical surface.

4. The needle winding assembly according to claim 3, wherein: A side wall of at least one of the first sub-winding needles facing another of the first sub-winding needles is formed with an escape opening, and the escape opening is communicated with the accommodating cavity and the corresponding two matching openings respectively, so as to be suitable for avoiding the corresponding second sub-winding needle.

5. The needle winding assembly according to claim 3 or 4, wherein: A partition is provided in the accommodating cavity, and the partition is connected to two opposite side walls of the accommodating cavity respectively, so as to divide the accommodating cavity into two chambers arranged in sequence along the second direction, and the two chambers correspond to two second winding pins respectively.

6. The needle winding assembly according to any one of claims 3 to 5, wherein: The winding needle assembly has a center line extending along the second direction, The two first sub-winding needles are respectively arranged on both sides of the center line in the first direction; and / or, The two second sub-winding needles of at least one second winding needle are respectively arranged on both sides of the center line in the first direction.

7. The needle winding assembly according to any one of claims 1 to 6, wherein: The needle winding assembly also includes: Two clamping members are arranged opposite to each other, and the two clamping members can move relative to each other to clamp the coiled material. The two clamping members are respectively arranged corresponding to the two first sub-coiling needles.

8. The needle winding assembly according to any one of claims 1 to 7, wherein: The outer peripheral walls of the two first sub-winding needles are arranged opposite to each other, and a groove is formed on the outer peripheral wall of each of the first sub-winding needles. The grooves of the two first sub-winding needles are arranged opposite to each other in the radial direction of the winding needle assembly.

9. The needle winding assembly according to any one of claims 1 to 8, wherein: The second winding needle moves within the cross section of the winding needle assembly to switch the winding needle assembly between the first state and the second state.

10. The needle winding assembly according to claim 9, wherein: At least one of the second winding needles is movable relative to the first winding needle along the second direction.

11. The needle winding assembly according to claim 10, wherein: The second states are multiple and are respectively from the first gear to the Nth gear. From the first gear to the Nth gear, the width of the winding needle assembly in the second direction decreases.

12. A winding device, wherein: include: A winding needle assembly, wherein the winding needle assembly is a winding needle assembly according to any one of claims 1 to 11; A first driving mechanism, the first driving mechanism is used to drive the winding needle assembly to rotate around its central axis; A second driving mechanism, wherein the second driving mechanism is used to drive at least one of the first sub-winding needles to move along the first direction.

13. The winding device according to claim 12, wherein: In the first state, the second winding needle is located outside the first sub-winding needle; The winding device also includes: A third driving mechanism is used to drive the second winding needle to move relative to the first winding needle along the second direction, so that the winding needle assembly switches between the first state and the second state.

14. A winding method, wherein: The winding needle assembly includes a first winding needle and a second winding needle, the first winding needle includes two first sub-winding needles arranged opposite to each other in a first direction and capable of moving relative to each other in the first direction, each of the first sub-winding needles has an accommodating cavity formed therein, the accommodating cavity penetrates two side walls of the first sub-winding needle in the second direction to respectively form a matching opening, the first winding needle is respectively provided with the second winding needle on both sides along the second direction, each of the second winding needles can move relative to the first sub-winding needle, and the winding needle assembly is configured to be switchable between a first state and a second state, In the first state, the outer peripheral wall of the second winding needle and the outer peripheral wall of the first sub-winding needle are on the same preset cylindrical surface; in the second state, the second winding needle is located on the inner side of the preset cylindrical surface and at least a portion of the second winding needle extends into the accommodating cavity through the corresponding matching opening, so that the width of the winding needle assembly in the second direction in the second state is smaller than the width of the winding needle assembly in the second direction in the first state, and the first direction and the second direction are perpendicular to the axial direction of the winding needle assembly in pairs. The winding method comprises: The winding needle assembly winds the coil in the first state until a preset condition is met, and the winding needle assembly stretches the coil at least once. During the stretching process, the winding needle assembly switches to the second state and increases the distance between the two first sub-winding needles in the first direction.

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