Winding device

Abstract

The present invention relates to a winding device for winding the electrode sheets of an electric core, which comprises: a driving mandrel; a deformable structure sleeved on the outer peripheral surface of the driving mandrel, the deformable structure comprising a deformable bladder part and a deformable supporting part, the deformable bladder part being connected to the outer peripheral surface to isolate the deformable supporting part from the driving mandrel, the deformable supporting part being in a cylindrical structure, the deformable supporting part being sleeved on the outer periphery of the deformable bladder part, and the deformable bladder part being capable of switching between an expanded state and a contracted state; wherein, the deformable bladder part that switches between the expanded state and the contracted state can drive the whole deformable supporting part to expand or contract in the radial direction of the driving mandrel, so that the deformable supporting part switches between a winding position and a discharging position, and the electrode sheets of the electric core can be wound on the outer peripheral surface of the deformable supporting part in the winding position. The winding device of this embodiment can smoothly and successfully separate from the wound electric core, reduce the possibility of the electrode sheets being taken out, and improve the finished product rate of the electric core.

Description

Technical Field

[0001] The invention relates to the technical field of batteries, and in particular to a winding device. Background Art

[0002] Secondary batteries have the characteristics of high energy density and green environmental protection, becoming a new trend in energy development. Among them, the core component of the secondary battery, the battery cell, is generally formed by winding the first pole piece, the second pole piece and the diaphragm through a winding mechanism. The winding mechanism includes a winding needle for winding. After the winding needle completes the winding work, the winding needle needs to be pulled out of the battery cell formed by winding. However, since the winding needle and the battery cell are in a tight fit, when the winding needle is pulled out of the battery cell, the winding needle will easily bring out the pole piece formed by the first pole piece, the second pole piece and the diaphragm, thereby causing the entire battery cell to be scrapped. Summary of the invention

[0003] The embodiment of the present invention provides a winding device, which can ensure that the separation process of the wound battery cell is smooth and smooth, reduce the possibility of the pole piece being carried out, and improve the battery cell yield.

[0004] On the one hand, an embodiment of the present invention provides a winding device for winding a battery cell electrode sheet, the winding device comprising:

[0005] A transmission core shaft; a deformable structure, which is sleeved on the outer circumferential surface of the transmission core shaft, the deformable structure comprises a deformable capsule portion and a deformable support portion, the deformable capsule portion is connected to the outer circumferential surface to isolate the deformable support portion from the transmission core shaft, the deformable support portion is a cylindrical structure, the deformable support portion is sleeved on the outer circumference of the deformable capsule portion, and the deformable capsule portion can switch between an expanded state and a contracted state; wherein the deformable capsule portion that switches between an expanded state and a contracted state can drive the deformable support portion to expand or contract along the radial direction of the transmission core shaft as a whole, so that the deformable support portion can switch between a winding position and a unloading position, and the battery cell pole piece can be wound on the outer circumferential surface of the deformable support portion in the winding position.

[0006] According to one aspect of the embodiments of the present invention, the deformable sac portion is an integrated cylindrical structure, and the deformable sac portion is sleeved on the outer circumferential surface of the transmission core shaft.

[0007] According to one aspect of the embodiments of the present invention, in a cross section of the deformable supporting portion in the rolled-up position, the contour of the outer peripheral surface of the deformable supporting portion is circular or elliptical.

[0008] According to one aspect of the embodiments of the present invention, the deformable sac portion and the deformable support portion are an integrated structure.

[0009] According to one aspect of the embodiments of the present invention, the deformable sac portion and the deformable support portion are separate structures.

[0010] According to one aspect of an embodiment of the present invention, the deformable structure further includes an elastic part, and the elastic part is disposed between the deformable supporting part and the deformable bladder part.

[0011] According to one aspect of an embodiment of the present invention, the outer peripheral surface of the drive mandrel is a conical surface, and the surface of the deformable bladder part in contact with the drive mandrel matches the shape of the outer peripheral surface.

[0012] According to one aspect of an embodiment of the present invention, the deformable bladder part has an input port and an output port for conveying a fluid medium, and the drive mandrel is provided with an input channel communicating with the input port and an output channel communicating with the output port.

[0013] According to one aspect of an embodiment of the present invention, the drive mandrel includes an inner shaft and an outer shaft sleeve which are sleeved with each other and sealed and connected, the outer shaft sleeve is disposed between the inner shaft and the deformable bladder part, the inner shaft has a receiving hole, the input channel and the output channel both penetrate through the outer shaft sleeve and the inner shaft and are connected with the receiving hole, and the winding device further includes an input pipe fitting and an output pipe fitting disposed in the receiving hole, the input pipe fitting and the output pipe fitting are respectively connected with the input channel and the output channel and are sealed and connected with the inner shaft or the outer shaft sleeve.

[0014] According to one aspect of an embodiment of the present invention, the winding device further includes a first one-way flow guiding member and a second one-way flow guiding member, the first one-way flow guiding member is disposed in the input channel and is located downstream of the input pipe fitting, and the second one-way flow guiding member is disposed in the output channel and is located upstream of the output pipe fitting.

[0015] According to one aspect of an embodiment of the present invention, the drive mandrel includes a first end face and a second end face which are oppositely disposed along its own axial direction, the input port and the output port are axially offset along the axial direction of the drive mandrel, wherein the input port is close to the first end face and the output port is close to the second end face.

[0016] According to one aspect of an embodiment of the present invention, the deformable bladder part has a flow exchange port for exchanging a fluid medium, the drive mandrel is provided with a flow exchange channel communicating with the flow exchange port, and the winding device further includes a flow exchange pipe fitting which is connected with the flow exchange channel and is sealed and connected with the drive mandrel.

[0017] According to one aspect of an embodiment of the present invention, the deformable supporting part is an insulating structure.

[0018] According to one aspect of an embodiment of the present invention, the winding device further includes an ear flattening component, and the ear flattening component has an air extraction channel which penetrates through the outer peripheral surface of the deformable supporting part and forms an air extraction port on the outer peripheral surface.

[0019] According to one aspect of an embodiment of the present invention, the ear flattening component includes a flow dividing component disposed in the air extraction channel, the flow dividing component is connected with the deformable supporting part, and the flow dividing component has two or more flow dividing holes communicating with the air extraction channel.

[0020] According to one aspect of an embodiment of the present invention, the tab flattening member further includes a filtering member disposed in the air extraction channel, and the filtering member is disposed downstream of the flow dividing member.

[0021] According to one aspect of an embodiment of the present invention, the driving mandrel includes an inner shaft and an outer shaft sleeve sleeved with each other. The outer shaft sleeve is disposed between the inner shaft and the deformable bladder portion. The inner shaft has a receiving hole. The air extraction channel penetrates through the deformable bladder portion, the inner shaft and the outer shaft sleeve and is connected to the receiving hole. The tab flattening member further includes a flattening air extraction pipe member. At least a part of the flattening air extraction pipe member is disposed in the receiving hole and is connected to the air extraction channel. The flattening air extraction pipe member is hermetically connected to the driving mandrel to seal the air extraction channel.

[0022] The winding device according to an embodiment of the present invention includes a driving mandrel and a deformable structure connected to the driving mandrel. The deformable structure includes a deformable bladder portion and a deformable supporting portion. The deformable bladder portion can expand or contract radially along the driving mandrel by itself, thereby driving the deformable supporting portion to expand or contract synchronously, so as to realize the switching of the deformable supporting portion between the winding position and the unloading position. The deformable supporting portion maintains an expanded state at the winding position so that the battery cell pole piece can be wound around the outer peripheral surface of the deformable supporting portion. After the winding work is completed, the deformable supporting portion and the deformable bladder portion contract synchronously to reduce their own sizes, so as to form a loose fit with the wound battery cell to realize automatic separation of the two, and then be pulled out from the wound battery cell along the withdrawal direction to complete the unloading. Since the friction resistance between the winding device and the battery cell pole piece is small and adhesion is not likely to occur when the winding device is pulled out from the wound battery cell, the pulling-out process of the winding device is smooth and stable, reducing the possibility of the battery cell pole piece being taken out together, ensuring the structural integrity of the battery cell pole piece after winding, and effectively improving the yield of the wound battery cell. Description of the Drawings

[0023] The features, advantages and technical effects of the exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0024] Figure 1 is a schematic structural view of a wound battery cell according to an embodiment of the present invention;

[0025] Figure 2 is a schematic cross-sectional structural view of a wound battery cell according to an embodiment of the present invention;

[0026] Figure 3 is a schematic cross-sectional structural view of a winding device in a winding state according to an embodiment of the present invention;

[0027] Figure 4 is Figure 3 a side view structure diagram in the direction of A in

[0028] Figure 5 It is a schematic side view structure diagram of a winding device according to another embodiment of the present invention;

[0029] Figure 6 is Figure 3 a schematic cross-sectional structure diagram of the winding device in the discharging state in the embodiment;

[0030] Figure 7 is a schematic cross-sectional structure diagram of the winding device in the winding state according to another embodiment of the present invention;

[0031] Figure 8 is a schematic cross-sectional structure diagram of the winding device in the winding state according to still another embodiment of the present invention;

[0032] Figure 9 is Figure 8 a schematic cross-sectional structure diagram of the winding device in the discharging state in the embodiment;

[0033] Figure 10 is Figure 8 an enlarged view at position B in;

[0034] Figure 11 is Figure 8 an enlarged view at position C in;

[0035] Figure 12 is a schematic cross-sectional structure diagram of the winding device in the winding state according to yet another embodiment of the present invention;

[0036] Figure 13 is a schematic cross-sectional structure diagram of the winding device in the winding state according to still another embodiment of the present invention;

[0037] Figure 14 is Figure 13 an enlarged view at position D in.

[0038] In the drawings, the drawings are not drawn to actual scale.

[0039] Marking description:

[0040] 1. Battery cell; 1a. Tab; 1b. Positive electrode plate; 1c. Negative electrode plate; 1d. Separator;

[0041] 10. Winding device;

[0042] 11. Driving mandrel; 11a. Outer peripheral surface; 11b. Input channel; 11c. Output channel; 11e. First end face; 11f. Second end face; 11g. Commutation channel; 11h. Accommodating hole; 111. Inner shaft; 112. Outer shaft sleeve;

[0043] 12. Deformable structure; 121. Deformable bladder part; 121a. Input port; 121b. Output port; 121c. Flow conversion port; 122. Deformable support part; 122a. Outer peripheral surface; 123. Elastic part;

[0044] 13. Input pipe fitting;

[0045] 14. Output pipe fitting;

[0046] 15. First one-way flow guiding part;

[0047] 16. Second one-way flow guiding part;

[0048] 17. Sealing part;

[0049] 18. Tab flattening part; 180. Air extraction channel; 181. Flattening air extraction pipe fitting; 182. Shunt part; 182a. Shunt hole; 183. Filter part;

[0050] 19. Flow conversion pipe fitting;

[0051] 20. Coupling;

[0052] 21. Bearing;

[0053] X. Exit direction. Detailed implementation mode

[0054] The following further describes in detail the implementation mode of the present invention in conjunction with the drawings and embodiments. The following detailed description of the embodiments and the drawings are used to exemplarily illustrate the principle of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0055] In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "a plurality" is two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] To better understand the present invention, the following will describe in detail the winding device 10 according to an embodiment of the present invention with reference to Figures 1 to 14 All the dotted lines shown in all the drawings are only for illustration and do not represent specific physical structures.

[0058] Refer to Figure 1 and Figure 2 As shown, the wound cell 1 according to the embodiment of the present invention is formed by winding the cell electrodes and then shaping them. The cell 1 has an extended tab 1a. The cell electrodes include a positive electrode tab 1b, a negative electrode tab 1c, and a separator 1d. The separator 1d is an insulator between the positive electrode tab 1b and the negative electrode tab 1c. Each of the positive electrode tab 1b and the negative electrode tab 1c has a thin film for conducting electricity. The thin film of the positive electrode tab 1b has a first coating area coated with a positive active material and a positive tab that is not coated with the positive active material. The thin film of the negative electrode tab 1c has a second coating area coated with a negative active material and a negative tab that is not coated with the active material.

[0059] Refer to Figure 3 and Figure 4 As shown, an embodiment of the present invention provides a winding device 10 for winding cell electrodes. The cell electrodes are wound by the winding device 10 according to this embodiment and then shaped to form a wound cell 1. The winding device 10 according to this embodiment includes a driving mandrel 11 and a deformable structure body 12 sleeved on the driving mandrel 11. Here, the deformability in this embodiment means that the component itself has the performance of being deformable. The deformable structure body 12 has a central hole, and the driving mandrel 11 is inserted into the central hole and fixedly connected to the deformable structure body 12. The deformable structure body 12 according to this embodiment is connected to the outer peripheral surface 11a of the driving mandrel 11. The deformable structure body 12 according to this embodiment includes a deformable bladder portion 121 and a deformable support portion 122. The deformable structure body 12 is connected to the outer peripheral surface 11a of the driving mandrel 11 through the deformable bladder portion 121. The deformable support portion 122 has a cylindrical structure. The deformable support portion 122 is sleeved on the outer periphery of the deformable bladder portion 121. The deformable bladder portion 121 can isolate the deformable support portion 122 from the driving mandrel 11, so that the space between the deformable support portion 122 and the driving mandrel 11 is completely filled and isolated by the deformable bladder, and they do not contact each other.

[0060] The deformable bladder portion 121 according to this embodiment can switch between an expanded state (refer to Figure 3 as shown) and a contracted state (refer to Figure 6 as shown). The deformable bladder portion 121 that switches between the expanded state and the contracted state can drive the entire deformable support portion 122 to expand or contract radially along the driving mandrel 11. When the entire deformable support portion 122 expands or contracts radially along the driving mandrel 11, it can be in a winding position (refer to Figure 3 as shown) and a discharging position (refer toFigure 6 switch between the states as shown in the figure. The electrode sheet of the battery cell can be wound around the outer peripheral surface 122a of the deformable support portion 122 in the winding position, and finally a wound battery cell 1 can be formed. After the winding process of the electrode sheet of the battery cell is completed by the winding device 10, the deformable bladder portion 121 is controlled to switch from the expanded state to the contracted state. During the radial contraction of the deformable bladder portion 121 along the drive mandrel 11, the deformable bladder portion 121 will synchronously drive the deformable support portion 122 to gradually contract radially along the drive mandrel 11 from the expanded state. The maximum outer diameter dimension of the cross section of the deformable support portion 122 in the expanded state is greater than the maximum outer diameter dimension of the cross section of the deformable support portion 122 in the contracted state. The deformable support portion 122 can perform a winding action in the winding position and a discharging action in the discharging position. When the deformable support portion 122 switches from the winding position to the discharging position, the tight fit between the outer peripheral surface 122a of the deformable support portion 122 and the wound battery cell 1 will change to a loose fit. In this way, after the winding process of the electrode sheet of the battery cell is completed by the winding device 10, the deformable structure 12 performs a contraction action, so that a loose fit is formed between the deformable support portion 122 and the wound battery cell 1, reducing the frictional resistance between the outer peripheral surface 122a of the deformable support portion 122 and the wound battery cell 1, and at the same time reducing the possibility of adhesion between the outer peripheral surface 122a of the deformable support portion 122 and the wound battery cell 1. Thus, the winding device 10 of this embodiment can smoothly withdraw from the wound battery cell 1 along the exit direction X (see Figure 6 as shown in the figure) to complete the discharging work, thereby reducing the possibility of damaging the structure of the wound battery cell 1, improving the withdrawal work efficiency of the winding device 10, increasing the yield rate of the wound battery cell 1, and effectively reducing the production cost.

[0061] See Figure 4 As shown in the figure, the number of the deformable bladder portions 121 included in the deformable structure 12 of this embodiment can be one. The deformable bladder portion 121 of this embodiment is an integral cylindrical structure. The deformable bladder portion 121 is sleeved on the outer peripheral surface 11a of the drive mandrel 11. It is easy to understand that, see Figure 5 as shown in the figure, the number of the deformable bladder portions 121 included in the deformable structure 12 of this embodiment can also be two or more. Two or more deformable bladder portions 121 are evenly distributed along the circumferential direction of the drive mandrel 11. In one example, the deformable bladder portion 121 is fixedly connected to the outer peripheral surface 11a of the drive mandrel 11 by bonding, so as to facilitate the removal of the deformable bladder portion 121 from the drive mandrel 11, which is beneficial to the later replacement of the deformable structure 12.

[0062] In this embodiment, in the cross-section of the deformable support portion 122 in the winding position, the contour of the outer peripheral surface 122a of the deformable support portion 122 is circular or elliptical, so as to ensure that the transition of each area of the outer peripheral surface 122a is smooth, and no stress concentration will be formed in the local area of the wound battery cell pole piece, reducing the possibility of damaging or puncturing the battery cell pole piece, and ensuring the structural integrity of the formed battery cell 1. In one example, the shrinkage process of the deformable support portion 122 is uniform, so that in the cross-section of the deformable support portion 122 in the unloading position, the contour of the outer peripheral surface 122a of the deformable support portion 122 can also be kept circular or elliptical. At this time, the maximum dimension of the outer peripheral surface 122a from the axis of the drive mandrel 11 is smaller than the maximum dimension of the outer peripheral surface 122a from the axis of the drive mandrel 11 in the winding position.

[0063] In one embodiment, referring to Figure 3 as shown, the deformable bladder portion 121 and the deformable support portion 122 are of an integral structure, ensuring high connection strength between the two, and at the same time, the expansion or contraction actions of the two can be synchronized. The deformable bladder portion 121 and the deformable support portion 122 can be manufactured by an integral molding method. In one example, the materials of both the deformable bladder portion 121 and the deformable support portion 122 are elastic materials such as rubber or silica gel, so that both the deformable bladder portion 121 and the deformable support portion 122 have good deformation performance. Optionally, the deformable bladder portion 121 and the deformable support portion 122 can be manufactured by an injection molding method.

[0064] In one embodiment, referring to Figure 7 as shown, the deformable bladder portion 121 and the deformable support portion 122 are of a split structure. The deformable bladder portion 121 and the deformable support portion 122 are detachably connected, which is convenient to remove the deformable support portion 122 from the deformable bladder portion 121 and replace it with a new deformable support portion 122, reducing the use and maintenance costs. The deformable bladder portion 121 and the deformable support portion 122 of this embodiment can be manufactured using different materials. In one example, the deformable bladder portion 121 can be manufactured using rubber or silica gel materials, while the deformable support portion 122 can be manufactured using insulating materials such as Teflon (polytetrafluoroethylene), so that the deformable support portion 122 itself has both insulating properties and deformation properties.

[0065] Further, referring to Figure 8 and Figure 9As shown, the deformable structure 12 further includes an elastic portion 123. The elastic portion 123 is disposed between the deformable support portion 122 and the deformable bladder portion 121. The deformable support portion 122 and the deformable bladder portion 121 are separated by the elastic portion 123 and do not directly contact each other. The elastic portion 123 of this embodiment is an integral cylindrical structure, which is sleeved on the outer periphery of the deformable bladder portion 121 and is detachably connected to the deformable bladder portion 121. In one example, the elastic portion 123 is fixedly connected to the deformable bladder portion 121 and the elastic portion 123 is fixedly connected to the deformable support portion 122 by an adhesive method. The elastic portion 123 of this embodiment can play a role in restraining and shaping the deformable bladder portion 121, so as to ensure that the structure of the deformable bladder portion 121 is regular when it is in an expanded state, so that the outer peripheral surface 122a of the deformable support portion 122 is smooth and flat after expansion, and finally it is beneficial to improve the structural regularity of the wound battery cell 1. It is easy to understand that the number of the elastic portions 123 can also be more than two. More than two elastic portions 123 are evenly distributed along the circumferential direction of the drive core shaft 11. The material of the elastic portion 123 of this embodiment can be an elastic material such as rubber or silica gel.

[0066] The drive core shaft 11 of this embodiment includes a first end face 11e and a second end face 11f that are oppositely arranged along its own axial direction. The outer peripheral surface 11a of the drive core shaft 11 of this embodiment connects the first end face 11e and the second end face 11f and is itself a conical surface. The outer diameter dimension of the end corresponding to the first end face 11e of the drive core shaft 11 of this embodiment is larger than the outer diameter dimension of the end corresponding to the second end face 11f. The inner surface of the hollow deformable bladder portion 121 is also a conical inclined surface, so that the surface of the deformable bladder portion 121 in contact with the drive core shaft 11 matches the shape of the outer peripheral surface 11a of the drive core shaft 11. In this way, during the process of the deformable bladder portion 121 changing from the expanded state to the contracted state, under the restraint of the drive core shaft 11, the outer circumferential surface of the deformable bladder portion 121 will gradually turn into a conical inclined surface. For the deformable bladder portion 121 in the contracted state, the outer diameter dimension of the cross section near the first end face 11e is larger than the outer diameter dimension of the cross section near the second end face 11f. Thus, the outer diameter dimension of the cross section of the deformable support portion 122 sleeved on the outer periphery of the deformable bladder portion 121 near the first end face 11e is larger than the outer diameter dimension of the cross section near the second end face 11f, so that the outer peripheral surface 122a of the deformable support portion 122 is also a conical inclined surface. When the winding device 10 is pulled out from the wound battery cell 1 along the exit direction X, the wound battery cell 1 will gradually and slowly slide down along the outer peripheral surface 122a of the deformable support portion 122. Thus, the wound battery cell 1 itself is subjected to a small impact force, and the pole piece is not easily structurally damaged during the pulling out process of the winding device 10. In one embodiment, the drive core shaft 11 of this embodiment can also be an overall cylindrical structure.

[0067] In one embodiment, the deformable bladder portion 121 has an input port 121a and an output port 121b for conveying a fluid medium. The drive mandrel 11 has an input channel 11b communicating with the input port 121a and an output channel 11c communicating with the output port 121b. In this embodiment, the deformable bladder portion 121 is inflated by filling a fluid medium into the deformable bladder portion 121 through the input channel 11b and the input port 121a. The fluid medium filled into the deformable bladder portion 121 is pumped out through the output channel 11c and the output port 121b to control the contraction of the deformable bladder portion 121. The fluid medium in this embodiment can be a liquid or a gas. Preferably, the fluid medium filled into the deformable bladder portion 121 is a gas. When the fluid medium filled into the deformable bladder portion 121 is a gas, when the winding device 10 is driven by an external driving force to switch from a stopped state to a high-speed rotating state, the damping force of the gas on the entire winding device 10 is small and will not apply an excessive reverse torque to the deformable bladder portion 121, thereby ensuring the smooth start-up process and speed-up process of the winding device 10. At the same time, when the gas leaks, it will not cause pollution to the winding device 10 or other components, improving the use safety of the winding device 10.

[0068] In one embodiment, the outer peripheral surface 11a of the drive mandrel 11 is a conical surface. The drive mandrel 11 includes a first end face 11e and a second end face 11f that are oppositely arranged along its own axis. The internal space of the deformable bladder portion 121 gradually increases from the first end face 11e to the second end face 11f. The input port 121a and the output port 121b included in the deformable bladder portion 121 are arranged offset along the axis of the drive mandrel 11. Among them, the input port 121a is close to the first end face 11e, and the output port 121b is close to the second end face 11f. In this way, when filling a fluid medium into the deformable bladder portion 121 through the input port 121a, the fluid medium can be filled into the deformable bladder portion 121 from the end with a smaller internal space of the deformable bladder portion 121, and then the fluid medium gradually flows towards the end with a larger internal space of the deformable bladder portion 121, ensuring that the portion of the deformable bladder portion 121 close to the first end face 11e expands first, and then gradually expands towards the second end face 11f, improving the smoothness of the inflation process of the deformable bladder portion 121. When pumping out the fluid medium filled into the deformable bladder portion 121 through the output port 121b, the fluid medium can be pumped out from the end with a larger internal space of the deformable bladder portion 121, ensuring that the portion of the deformable bladder portion 121 close to the second end face 11f contracts first, and then gradually contracts towards the first end face 11e, improving the smoothness of the contraction process of the deformable bladder portion 121.

[0069] The drive mandrel 11 of this embodiment includes an inner shaft 111 and an outer shaft sleeve 112 that are sleeved with each other and sealed and connected. The outer shaft sleeve 112 is disposed between the inner shaft 111 and the deformable bladder portion 121. In this embodiment, the outer shaft sleeve 112 and the inner shaft 111 can be fixedly connected by an interference fit. The materials of the inner shaft 111 and the outer shaft sleeve 112 in this embodiment can be the same, both being materials such as steel or iron. The materials of the inner shaft 111 and the outer shaft sleeve 112 in this embodiment can also be different. Among them, the inner shaft 111 can be a metal material such as steel or iron, while the outer shaft sleeve 112 can be an engineering plastic. The inner shaft 111 has a receiving hole 11h. The input channel 11b and the output channel 11c both penetrate through the outer shaft sleeve 112 and the inner shaft 111 and are connected to the receiving hole 11h. Refer to Figure 10 and Figure 11 As shown, the winding device 10 further includes an input pipe fitting 13 and an output pipe fitting 14 disposed in the receiving hole 11h of the inner shaft 111. The input pipe fitting 13 and the output pipe fitting 14 are respectively connected to the input channel 11b and the output channel 11c. In this embodiment, a fluid medium is filled into the deformable bladder portion 121 through the input pipe fitting 13, the input channel 11b, and the input port 121a to cause the deformable bladder portion 121 to expand, thereby driving the deformable support portion 122 to expand and finally reach the winding position. The fluid medium inside the deformable bladder portion 121 is pumped out through the output pipe fitting 14, the output channel 11c, and the output port 121b to cause the deformable bladder portion 121 to contract, thereby driving the deformable support portion 122 to contract and finally reach the unloading position. Disposing the input pipe fitting 13 and the output pipe fitting 14 in the receiving hole 11h of the inner shaft 111 is beneficial to improving the overall compactness of the winding device 10. At the same time, the input pipe fitting 13 and the output pipe fitting 14 are closer to the axis of the rotating mandrel. Thus, when the winding device 10 rotates at a high speed, the input pipe fitting 13 and the output pipe fitting 14 have a smaller impact on the stability of the entire winding device 10. The input pipe fitting 13 and the output pipe fitting 14 are respectively sealed and connected to the inner shaft 111 or the outer shaft sleeve 112. In one example, the input pipe fitting 13 and the output pipe fitting 14 are respectively sealed and connected to the inner shaft 111 or the outer shaft sleeve 112 through a seal 17. The seal 17 of this embodiment can be an elastic material such as rubber or silica gel. The seal 17 and the input channel 11b or the output channel 11c are hermetically connected by an interference fit. Optionally, a card slot is provided on the inner shaft 111 or the outer shaft sleeve 112, and the seal 17 is snapped into the card slot, so that the input pipe fitting 13 and the output pipe fitting 14 are respectively hermetically connected to the input channel 11b and the output channel 11c, and at the same time, the position of the seal 17 is restricted and defined. Optionally, the seal 17 is an annular structure with a central hole, so that the seal 17 can be sleeved on the outer periphery of the input pipe fitting 13 or the output pipe fitting 14 to achieve a sealing fit. Optionally, switch valves are provided on both the input pipe fitting 13 and the output pipe fitting 14 to facilitate controlling the opening and closing of the input pipe fitting 13 and the output pipe fitting 14.

[0070] See Figure 10 and Figure 11 As shown, the winding device 10 of this embodiment further includes a first one-way flow guide member 15 and a second one-way flow guide member 16. The first one-way flow guide member 15 is disposed in the input channel 11b and downstream of the input pipe fitting 13. The first one-way flow guide member 15 can prevent the fluid medium filled into the deformable bladder portion 121 from flowing back to the input pipe fitting 13, ensuring the safety and smoothness of the fluid medium filling process, and at the same time preventing the fluid medium in the expanded deformable bladder portion 121 from leaking from the input pipe fitting 13. The second one-way flow guide member 16 is disposed in the output channel 11c and upstream of the output pipe fitting 14. The second one-way flow guide member 16 can prevent the fluid medium drawn from the inside of the deformable bladder portion 121 from flowing back to the deformable bladder portion 121, ensuring the smoothness of the contraction process of the deformable bladder portion 121. Optionally, both the first one-way flow guide member 15 and the second one-way flow guide member 16 are one-way valves or one-way conduction louver structures.

[0071] In another embodiment, see Figure 12 As shown, the deformable bladder portion 121 has a fluid exchange port 121c for exchanging fluid medium. The drive mandrel 11 is provided with a fluid exchange channel 11g communicating with the fluid exchange port 121c. The fluid medium is filled into the deformable bladder portion 121 or the fluid medium inside the deformable bladder portion 121 is drawn out through the fluid exchange channel 11g and the fluid exchange port 121c. The winding device 10 further includes a fluid exchange pipe fitting 19 communicating with the fluid exchange channel 11g. The drive mandrel 11 of this embodiment has a receiving hole 11h extending along its own axial direction. The winding device 10 further includes a fluid exchange pipe fitting 19 disposed in the receiving hole 11h. The fluid exchange pipe fitting 19 communicates with the fluid exchange channel 11g and is sealingly connected to the drive mandrel 11. The structural design of filling the fluid medium into the deformable bladder portion 121 or drawing out the fluid medium inside the deformable bladder portion 121 through the fluid exchange pipe fitting 19, the fluid exchange channel 11g and the fluid exchange port 121c can reduce the number of components and reduce the failure rate of the winding device 10. The fluid exchange pipe fitting 19 and the drive mandrel 11 of this embodiment are sealingly connected through a seal 17.

[0072] The deformable support portion 122 of the embodiment of the present invention is an insulating structure. The material of the deformable support portion 122 can be an insulating elastic material such as rubber, Teflon or plastic. Thus, the deformable support portion 122 not only has insulating properties itself, but also has a certain telescopic deformation performance in its own structure. Since the deformable support portion 122 is an insulating structure, no static electricity will be generated during the process of winding the battery core electrode sheet, reducing the interference and adverse effects on the winding process of the battery core electrode sheet. At the same time, it is not easy to have an adhesion phenomenon between the deformable support portion 122 and the battery core electrode sheet, ensuring the smoothness of the withdrawal process of the winding device 10 along the withdrawal direction X and preventing the battery core electrode sheet from being pulled out together.

[0073] See Figure 13 and Figure 14 As shown, the winding device 10 of the embodiment of the present invention further includes an ear flattening component 18. The ear flattening component 18 has an air extraction channel 180. The air extraction channel 180 penetrates through the outer peripheral surface 122a of the deformable support portion 122 and forms an air extraction port on the outer peripheral surface 122a. When the winding device 10 winds the electrode tab of the battery cell and the ear flattening component 18 is in the working state, the electrode tabs of the battery cell electrode tab will be stacked on the area of the outer peripheral surface 122a of the deformable support portion 122 close to the ear flattening component 18. The ear flattening component 18 can extract air from the atmospheric environment through the air extraction port, so as to form an air field in the spatial area around the electrode tab, so that the flowing air exerts a downward pressure on the electrode tab towards the outer peripheral surface 122a of the deformable support portion 122, so that each layer of electrode tab is subjected to a centripetal force, so that each layer of electrode tab can be stacked flatly in sequence, avoiding the folding and structural damage of the electrode tab in the high-speed rotation state.

[0074] The ear flattening component 18 of this embodiment further includes a flow splitting component 182 arranged in the air extraction channel 180. The flow splitting component 182 is connected to the deformable support portion 122. The flow splitting component 182 has more than two flow splitting holes 182a communicating with the air extraction channel 180. The flow splitting holes 182a on the flow splitting component 182 can control the air flow rate, ensure that the air flow rates drawn into each flow splitting hole 182a are uniform, so that the downward pressures received by each area on the electrode tab are kept balanced.

[0075] The ear flattening component 18 of this embodiment further includes a filtering component 183 arranged in the air extraction channel 180. The filtering component 183 is arranged downstream of the flow splitting component 182. The filtering component 183 can filter the air before entering the air extraction channel 180, reducing the possibility of external foreign objects entering the air extraction channel 180 and blocking the air extraction channel 180.

[0076] The battery cell electrode tab of this embodiment has a positive electrode tab and a negative electrode tab. The number of air extraction ports can be two. One air extraction port is arranged at the position corresponding to the positive electrode tab on the deformable support portion 122, and one air extraction port is arranged at the position corresponding to the negative electrode tab, respectively for applying centripetal force to the positive electrode tab and the negative electrode tab. Optionally, the number of air extraction ports can also be multiple, so that at least two air extraction ports are arranged at the position corresponding to the positive electrode tab on the deformable support portion 122, and at least two air extraction ports are arranged at the position corresponding to the negative electrode tab, so as to apply a greater and more balanced centripetal force to the positive electrode tab and the negative electrode tab.

[0077] The drive mandrel 11 of this embodiment includes an inner shaft 111 and an outer shaft sleeve 112 that are sleeved with each other. The outer shaft sleeve 112 is disposed between the inner shaft 111 and the deformable bladder portion 121. The inner shaft 111 has a receiving hole 11h. The air extraction channel 180 penetrates through the deformable bladder portion 121, the inner shaft 111, and the outer shaft sleeve 112 and communicates with the receiving hole 11h. The tab flattening member 18 further includes a flattening air extraction pipe member 181. At least a part of the flattening air extraction pipe member 181 is disposed in the receiving hole 11h of the inner shaft 111 and communicates with the air extraction channel 180. Disposing the flattening air extraction pipe member 181 in the receiving hole 11h of the inner shaft 111 is beneficial to improving the overall structural compactness of the winding device 10. Optionally, a switching valve is provided on the flattening air extraction pipe member 181 to facilitate controlling the opening and closing of the flattening air extraction pipe member 181. The flattening air extraction pipe member 181 is hermetically connected to the drive mandrel 11 to seal the air extraction channel 180. Optionally, the flattening air extraction pipe member 181 can be hermetically connected to the inner shaft 111 or the outer shaft sleeve 112 through a seal 17.

[0078] The drive mandrel 11 of this embodiment has a first cylinder protruding from the first end face 11e. The first cylinder can be connected to the coupling 20 so that an external drive member drives the winding device 10 to rotate through the coupling 20. The drive mandrel 11 further has a second cylinder protruding from the second end face 11f. The second cylinder can be connected to the bearing 21 to be supported on an external bracket through the bearing 21.

[0079] The winding device 10 of the embodiment of the present invention includes a drive mandrel 11 and a deformable structure body 12 connected to the drive mandrel 11. The deformable structure body 12 includes a deformable bladder portion 121 and a deformable support portion 122. The deformable bladder portion 121 itself can expand or contract along the radial direction of the drive mandrel 11, thereby driving the deformable support portion 122 to expand or contract synchronously, so as to realize the switching of the deformable support portion 122 between the winding position and the unloading position. The deformable support portion 122 remains in an expanded state at the winding position so that the electrode tab of the battery cell can be wound around the outer peripheral surface 122a of the deformable support portion 122. After the winding work is completed, the deformable support portion 122 and the deformable bladder portion 121 contract synchronously to reduce its own size, so as to form a loose fit with the wound battery cell 1 to realize automatic separation of the two. Then, the entire winding device 10 is pulled out from the wound battery cell 1 along the withdrawal direction X to complete the unloading. Since the friction resistance between the winding device 10 and the electrode tab of the battery cell is small and adhesion is not likely to occur when the winding device 10 is pulled out from the wound battery cell 1, the pulling-out process of the winding device 10 is smooth and stable, reducing the possibility of the electrode tab of the battery cell being taken out together, ensuring the structural integrity of the electrode tab of the battery cell after winding, not easily occurring loose winding, and effectively improving the yield of the wound battery cell 1.

[0080] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A winding device for winding the electrode tabs of an electric core, the winding device comprising: A driving mandrel; A deformable structure sleeved on the outer peripheral surface of the driving mandrel. The deformable structure includes a deformable bladder portion and a deformable supporting portion. The deformable bladder portion is detachably connected to the driving mandrel. The deformable bladder portion is connected to the outer peripheral surface to isolate the deformable supporting portion from the driving mandrel. The deformable supporting portion has a cylindrical structure and is sleeved on the outer periphery of the deformable bladder portion. The deformable bladder portion can switch between an expanded state and a contracted state; Wherein, the deformable bladder portion switching between the expanded state and the contracted state can drive the entire deformable supporting portion to expand or contract radially along the driving mandrel, so that the deformable supporting portion switches between a winding position and a discharging position, and the electrode tabs of the electric core can be wound around the outer peripheral surface of the deformable supporting portion in the winding position; The winding device further includes an ear flattening component having an air extraction channel that penetrates the outer peripheral surface of the deformable supporting portion and forms an air extraction port on the outer peripheral surface; The driving mandrel includes a receiving hole, and the air extraction channel penetrates the deformable bladder portion and the driving mandrel and is connected to the receiving hole.

2. The winding device according to claim 1, characterized in that, The deformable bladder portion is an integral cylindrical structure and is sleeved on the outer peripheral surface of the driving mandrel.

3. The winding device according to claim 1, characterized in that, In the cross-section of the deformable supporting portion in the winding position, the contour of the outer peripheral surface of the deformable supporting portion is circular or elliptical.

4. The winding device according to claim 1, characterized in that, The deformable bladder portion and the deformable supporting portion are of an integral structure.

5. The winding device according to claim 1, characterized in that, The deformable bladder portion and the deformable supporting portion are of a split structure.

6. The winding device according to claim 5, characterized in that, The deformable structure further includes an elastic portion disposed between the deformable supporting portion and the deformable bladder portion.

7. The winding device according to claim 1, characterized in that The outer peripheral surface of the driving mandrel is a conical surface, and the surface of the deformable bladder portion in contact with the driving mandrel matches the shape of the outer peripheral surface.

8. The winding device according to claim 1, characterized in that, The deformable bladder portion has an input port and an output port for conveying a fluid medium. The driving mandrel is provided with an input channel communicating with the input port and an output channel communicating with the output port.

9. The winding device according to claim 8, characterized in that, The driving mandrel includes an inner shaft and an outer shaft sleeve sleeved and sealingly connected to each other. The outer shaft sleeve is disposed between the inner shaft and the deformable bladder portion. The inner shaft has a receiving hole. The input channel and the output channel both penetrate the outer shaft sleeve and the inner shaft and are connected to the receiving hole. The winding device further includes an input pipe fitting and an output pipe fitting disposed in the receiving hole. The input pipe fitting and the output pipe fitting are respectively connected to the input channel and the output channel and are sealingly connected to the inner shaft or the outer shaft sleeve.

10. The winding device according to claim 9, characterized in that, The winding device further includes a first one-way flow guiding member and a second one-way flow guiding member. The first one-way flow guiding member is disposed in the input channel and is located downstream of the input pipe fitting. The second one-way flow guiding member is disposed in the output channel and is located upstream of the output pipe fitting.

11. The winding device according to claim 8, characterized in that, The drive mandrel includes a first end face and a second end face disposed opposite to each other along its own axial direction. The input port and the output port are arranged offset from each other along the axial direction of the drive mandrel. Among them, the input port is close to the first end face, and the output port is close to the second end face.

12. The winding device according to claim 1, characterized in that, The deformable bladder portion has a fluid exchange port for exchanging fluid media. The drive mandrel is provided with a fluid exchange channel connected to the fluid exchange port. The winding device further includes a fluid exchange pipe fitting, and the fluid exchange pipe fitting is connected to the fluid exchange channel and is sealingly connected to the drive mandrel.

13. The winding device according to claim 1, characterized in that, The deformable support portion is an insulating structure.

14. The winding device according to claim 1, characterized in that, The tab flattening member includes a flow splitting member disposed in the air extraction channel. The flow splitting member is connected to the deformable support portion, and the flow splitting member has two or more flow splitting holes communicating with the air extraction channel.

15. The winding device according to claim 14, characterized in that, The tab flattening member further includes a filtering member disposed in the air extraction channel, and the filtering member is disposed downstream of the flow splitting member.

16. The winding device according to claim 1, characterized in that, The drive mandrel includes an inner shaft and an outer shaft sleeve sleeved with each other. The outer shaft sleeve is disposed between the inner shaft and the deformable bladder portion. The inner shaft has the accommodation hole. The air extraction channel penetrates through the deformable bladder portion, the inner shaft and the outer shaft sleeve and is connected to the accommodation hole. The tab flattening member further includes a flattening air extraction pipe fitting. At least a part of the flattening air extraction pipe fitting is disposed in the accommodation hole and is connected to the air extraction channel. The flattening air extraction pipe fitting is sealingly connected to the drive mandrel to seal the air extraction channel.

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