Electrode slice winding device

Abstract

The invention relates to the technical field of battery processing equipment, in particular to an electrode slice winding device which comprises a revolution mechanism, a winding mechanism, a winding mechanism and an opening mechanism. The winding mechanism is arranged on the revolution mechanism, and the output end of the winding mechanism can rotate; each winding mechanism comprises a mounting base, a first expansion piece arranged on the mounting base and a rolling tongue piece mounted at the output end of the first expansion piece, each mounting base is mounted at the output end of the corresponding winding mechanism, and a pair of opening pieces capable of being opened and closed mutually is arranged at the outward end of each rolling tongue piece; the opening mechanisms are installed at the output ends of the winding mechanisms respectively, each opening mechanism is provided with a telescopic driving head, the driving heads movably penetrate through the rolling tongue pieces and are connected with the opposite inner sides of the two opening pieces in a sliding and clamping mode, and the driving heads can drive the two opening pieces to be opened and closed mutually. According to the electrode slice winding device, the overall tightness of the battery cell in the winding process can be adjusted, and the winding quality of the battery cell is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of battery processing, and in particular to an electrode sheet winding device. Background Art

[0002] The capacity of a lithium battery cell is affected by the tightness of the winding of the internal pole pieces and diaphragms. Under the same volume, the tighter the pole pieces and diaphragms are wound, the smaller the gap between each layer of pole pieces and diaphragms, and the longer the winding length of the pole pieces and diaphragms in a single lithium battery cell, and the greater the capacity. At present, lithium battery cells are generally obtained by winding pole pieces and diaphragms in sequence through a winding mechanism. In order to improve work efficiency, the current mainstream winding mechanism generally uses a revolution device to drive multiple self-rotating winding mechanisms to realize the winding of lithium battery cells separately.

[0003] For example, the patent with publication number CN117317395A-Negative electrode continuous winding equipment and lithium battery winding method discloses a winding mechanism. During winding, the winding mechanism clamps the negative electrode sheet and the diaphragm by a winding needle and directly winds them. There is no need to pre-wind the diaphragm, which saves the time of pre-winding the diaphragm head, improves the winding efficiency, and reduces the cost of winding the battery cell. However, in this patent, the negative electrode sheet unwinding mechanism needs to cooperate with the cutting and gluing mechanism to cut and paste the electrode sheet, which results in the negative electrode sheet unwinding mechanism being unable to cooperate with the winding needle to adjust the tightness of the negative electrode sheet and the diaphragm on the winding needle; at the same time, since the structure of the winding needle is relatively fixed, during the winding process, due to the instability of the electrode sheet and diaphragm feeding process, there is a certain amount of swing, and at the same time, the winding needle itself has a certain degree of deflection, which results in the electrode sheet and the diaphragm being easily offset and loosened when being wound around the winding needle, and the winding force is uneven, which in turn results in the battery cell being prone to relatively tight inner layer winding, and the outer layer winding error gradually accumulating and resulting in a relatively loose situation, resulting in an increase in the size of the battery cell, affecting the later processing. Especially for the pre-cut electrode sheet and diaphragm, the looseness of the battery cell during the above winding process is more serious. Summary of the invention

[0004] In order to overcome one of the deficiencies of the prior art, an object of the present invention is to provide an electrode sheet winding device, which can adjust the overall tightness of the battery cell during the winding process to ensure the winding quality of the battery cell.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] An electrode sheet winding device comprises a revolution mechanism, a winding mechanism, at least two groups of winding mechanisms and at least two groups of spreading mechanisms, the revolution mechanism can rotate on its own; at least two groups of winding mechanisms are provided and are respectively arranged on the revolution mechanism, and the output end of the winding mechanism can rotate on its own; the two groups of winding mechanisms each comprise a mounting seat, a first telescope arranged on the mounting seat and a rolling tongue piece installed on the output end of the first telescope, each of the mounting seats is installed on the output end of the corresponding winding mechanism, and a pair of spreading pieces that can open and close with each other are arranged on the outward end of the rolling tongue piece; the two groups of spreading mechanisms are respectively installed on the output end of each winding mechanism, and each of the spreading mechanisms is provided with a retractable driving head, the driving head moves through the rolling tongue piece and is slidably engaged with the inner sides opposite to the two spreading pieces, and the driving head can drive the two spreading pieces to open and close with each other.

[0007] Furthermore, a slope is provided on one end of the inner side of the two spreading pieces close to the rolling tongue piece, and the slopes on the two spreading pieces are arranged in a trumpet shape. A wedge-shaped head is provided on the outward end of the driving head, and the two side surfaces of the wedge-shaped head are respectively slidably connected to the two slopes, and the wedge-shaped head can drive the two spreading pieces to open and close each other.

[0008] Furthermore, the two slope surfaces are provided with inverted T-shaped grooves, and the two side surfaces of the wedge-shaped head are provided with clamping heads that match the inverted T-shaped grooves.

[0009] Furthermore, magnetic blocks are arranged in the two slope surfaces, and sliding sheets cooperating with the magnetic blocks are arranged on the two side surfaces of the wedge-shaped head.

[0010] Furthermore, sliding grooves and sliding tongues are alternately arranged on the opposite sides of the two opening pieces, and the sliding tongue on one opening piece can be slidably installed in the sliding groove of the other opening piece.

[0011] Furthermore, the telescopic end of the spreading mechanism is connected to the driving head through a driving buffer assembly, and a clamping needle is provided at one end of the driving buffer assembly facing the driving head. The telescopic end of the spreading mechanism can sequentially drive the clamping needle and the driving head to move outward, so that the clamping needle gradually approaches the two spreading pieces and cooperates with the two spreading pieces to clamp the ends of the battery pole pieces and makes the two spreading pieces gradually open.

[0012] Furthermore, the drive buffer assembly includes a connecting rod and a movable cylinder, one end of the connecting rod is movably inserted in one end of the movable cylinder, the other end of the connecting rod is movably inserted with the end of the driving head away from the outside, the other end of the movable cylinder is connected to the telescopic end of the expansion mechanism, the connecting rod is movably sleeved with a first spring, a second spring is arranged in the movable cylinder, the two ends of the second spring are respectively connected with the bottom of the movable cylinder and the end face of the connecting rod, the connecting rod is movably sleeved with a movable sleeve, the clamping needle is arranged on the end of the movable sleeve facing the driving head, one end of the first spring is connected to the side surface corresponding to the driving head, and the other end is connected to the end face of the movable sleeve to abut the other side surface of the movable sleeve against the end face of the corresponding end of the movable cylinder, and the stiffness coefficient of the second spring is much larger than the stiffness coefficient of the first spring.

[0013] Furthermore, an adjusting member is provided on the movable sleeve, and the adjusting member can adjust the inclination angle of the clamping needle relative to the structure composed of the two spreading sheets.

[0014] Furthermore, the winding mechanism includes a rotating flange, an outer gear ring arranged on one end of the rotating flange, and a driving motor arranged on the revolution mechanism. The rotating flange can be rotatably installed in the rotating hole of the revolution mechanism, the output end of the driving motor is meshed with the outer gear ring through a gear, the mounting seat and the spreading mechanism are both installed on the rotating flange, and the rolling tongue piece moves through the through hole on the rotating flange and is placed on the other side of the revolution mechanism.

[0015] Furthermore, the spreading mechanism includes a base and a second retractor disposed on the base, an output end of the second retractor is connected to the driving head, and the base is mounted on a rotating flange.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] An electrode sheet winding device of the present invention is provided with a pair of opening and closing expansion sheets designed on the basis of the existing winding mechanism, so that when the electrode sheet and the diaphragm are wound on the two expansion sheets in sequence, the expansion mechanism can be used to control the driving head to drive the two expansion sheets to gradually open each other, so that during the winding process of the battery cell, the inner circle can be gradually opened to adapt to each layer of newly wound electrode sheet and diaphragm, thereby ensuring that each layer of newly wound electrode sheet and diaphragm can be tightly wound on the previous layer, reducing the cumulative error of winding. At the same time, the driving head can also drive the two expansion sheets to close, which is conducive to the rapid release of the material from the two expansion sheets after the battery cell winding is completed in the later stage, improving the efficiency of material removal, and also reducing the scratching and wear of the inner circle electrode sheet or diaphragm by the expansion sheet. Compared with the traditional method of directly ejecting the battery cell from the winding needle, the entire ejection process is smoother.

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a front view of an embodiment of the present invention;

[0020] Figure 2 is a left side view of an embodiment of the present invention;

[0021] Figure 3 is a partial cross-sectional view of an embodiment of the present invention;

[0022] Figure 4 The structure diagram of the tongue rolling piece and the opening piece in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0023] Figure 5 The structure diagram of the tongue rolling piece and the opening piece in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0024] Figure 6 is a schematic diagram of the structure of the tongue rolling piece and the opening piece in another embodiment of the present invention;

[0025] Figure 7 is a partial cross-sectional view of an improved embodiment of the present invention;

[0026] Figure 8 It is a partial cross-sectional view of the cooperation between the rolling tongue piece and the opening piece in the improved embodiment of the present invention.

[0027] Description of Figure Numbers:

[0028] Revolution mechanism 100, rotating hole 110, turntable 120, winding mechanism 200, rotating flange 210, outer gear ring 220, driving motor 230, gear 240, perforation 250, winding mechanism 300, mounting seat 310, first retractor 320, rolling tongue piece 330, opening piece 340, slope 341, inverted T-slot 342, magnetic block 343, slide groove 344, sliding tongue 345, opening mechanism 400, driving head 410, wedge head 411, clamping head 412, sliding piece 413, base 420, second retractor 430, driving buffer assembly 500, clamping needle 510, connecting rod 520, movable cylinder 530, first spring 540, second spring 550, movable sleeve 560, adjusting member 570. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] See also Figures 1 to 8 The present application provides an electrode sheet winding device, comprising a revolution mechanism 100, a winding mechanism 200, at least two groups of winding mechanisms 300 and at least two groups of spreading mechanisms 400, wherein the revolution mechanism 100 can rotate on its own; the winding mechanism 200 is provided with at least two groups, and is respectively provided on the revolution mechanism 100, and the output end of the winding mechanism 200 can rotate on its own; the two groups of winding mechanisms 300 each include a mounting seat 310, a first retractor 320 provided on the mounting seat 310, and a rolling tongue piece 330 installed on the output end of the first retractor 320, each The mounting seat 310 is installed on the output end of the corresponding winding mechanism 200, and a pair of expansion pieces 340 that can open and close with each other are arranged on the outward end of the rolling tongue piece 330; two groups of expansion mechanisms 400 are respectively installed on the output end of each winding mechanism 200, and each expansion mechanism 400 is provided with a retractable driving head 410, and the driving head 410 moves through the rolling tongue piece 330 and is slidably engaged with the inner sides opposite to the two expansion pieces 340, and the driving head 410 can drive the two expansion pieces 340 to open and close with each other.

[0031] Among them, the first retractor 320 drives the rolling tongue piece 330 to retract, and its main purpose is to eject and remove the battery cell wound on the expansion piece 340. The first retractor 320 in the present application is a structure similar to a telescopic cylinder. The expansion piece 340 in the present application has an external dimension similar to that of the rolling tongue piece 330, which can facilitate the ejection of the wound battery cell in the later stage. In the present application, at least one end of the two expansion pieces 340 is slidably mounted on the outward end of the rolling tongue piece 330. Of course, in some embodiments, the outward end of the rolling tongue piece 330 is forked or U-shaped, and the two expansion pieces 340 are respectively mounted on each fork. Such a structural design can achieve space intensiveness to a certain extent, and also provide space for the installation of the drive head 410. The first retractor 320 in the present application can be a telescopic electric cylinder.

[0032] It should be noted that in the present application, how to judge whether the newly wound pole piece and diaphragm are tightly wound on the pole piece and diaphragm that have been wound in the inner layer can be achieved by setting a pressure sensor on the stretching sheet 340, and judging whether the newly wound pole piece and diaphragm are completely and tightly fitted on the already wound pole piece and diaphragm by judging the pressure value of the pressure sensor; or by setting a photoelectric sensor in the axial direction of the winding of the battery cell to detect whether the newly wound pole piece and diaphragm are completely and tightly fitted on the already wound pole piece and diaphragm. Of course, there are many other embodiments to achieve the above requirements, which the applicant will not elaborate on here. Of course, in some embodiments, after the pole piece and diaphragm are wound a certain number of times in sequence, the two stretching sheets 340 can be controlled to gradually open so that the already wound pole piece and diaphragm are gradually stretched and automatically adjusted to adapt to the opening degree of the two stretching sheets 340, thereby achieving the automatic tight winding of the already wound pole piece and diaphragm. This application adopts this method for adjustment.

[0033] The electrode sheet winding device is provided with a pair of opening and closing expansion sheets 340 designed to be adjustable on the basis of the existing winding mechanism 200. In this way, when the electrode sheet and the diaphragm are wound on the two expansion sheets 340 in sequence, the expansion mechanism 400 can control the drive head 410 to drive the two expansion sheets 340 to gradually open each other, so that during the winding process of the battery cell, the inner circle can be gradually expanded to adapt to each layer of newly wound electrode sheet and diaphragm, thereby ensuring that each layer of newly wound electrode sheet and diaphragm can be tightly wound on the previous layer, reducing the cumulative error of winding. At the same time, the drive head 410 can also drive the two expansion sheets 340 to close, which is conducive to the rapid release of the material from the two expansion sheets 340 after the battery cell winding is completed in the later stage, improving the efficiency of material removal, and also reducing the scratching and wear of the expansion sheet 340 on the inner circle electrode sheet or diaphragm. Compared with the traditional method of directly ejecting the battery cell from the winding needle, the entire ejection process is smoother.

[0034] See also Figures 1 to 3In one embodiment of the present application, the revolution mechanism 100 includes a turntable 120 and a driving structure for driving the turntable 120 to rotate, such as a servo motor, etc. These are conventional means and are not described in detail in this application. In another embodiment of the present application, the winding mechanism 200 includes a rotating flange 210, an outer gear ring 220 arranged on one end of the rotating flange 210, and a driving motor 230 arranged on the revolution mechanism 100. The rotating flange 210 can be rotatably installed in the rotating hole 110 of the revolution mechanism 100. The output end of the driving motor 230 is meshed with the outer gear ring 220 through a gear 240. The mounting seat 310 and the spreading mechanism 400 are both installed on the rotating flange 210. The rolling tongue piece 330 moves through the through hole 250 on the rotating flange 210 and is placed on the other side of the revolution mechanism 100. More specifically, the driving motor 230 is installed on one side of the turntable 120, and the mounting seat 310 and the spreading mechanism 400 are both installed on the same side of the turntable 120, which can facilitate installation and improve overall aesthetics.

[0035] The tongue-rolling piece 330 moves through the through hole 250 on the rotating flange 210. This arrangement is mainly for the purpose of, after the winding of the battery cell is completed, the two opening pieces 340 are closed to loosen the inner ring of the battery cell, and the tongue-rolling piece 330 shrinks along with the first retractor 320. At this time, the two opening pieces 340 and the battery cell gradually approach the end face of the rotating flange 210. Due to the end face of the rotating flange 210, the battery cell can be pushed down from the two opening pieces 340 in cooperation with the first retractor 320 to achieve the dropping of the battery cell. At this time, the first retractor 320 continues to extend, waiting for the next winding work.

[0036] In the above improved embodiment, in order to realize the telescopic action of the driving head 410 on the tongue rolling piece 330, the spreading mechanism 400 includes a base 420 and a second telescopic device 430 arranged on the base 420, the output end of the second telescopic device 430 is connected to the driving head 410, and the base 420 is installed on the rotating flange 210. Among them, the second telescopic device 430 is a telescopic electric cylinder or a motor screw structure; because the adjustment of the driving head 410 in this application is a micro-adjustment, it is more appropriate to use a telescopic electric cylinder for driving.

[0037] See also Figures 4 to 5In order to achieve the two spreading pieces 340 to better cooperate with the driving head 410 to achieve the opening and closing action, in the present application, a slope 341 is provided on the inner side of the two spreading pieces 340 close to the rolling tongue piece 330, and the slopes 341 on the two spreading pieces 340 are arranged in a trumpet shape. A wedge-shaped head 411 is provided on the outward end of the driving head 410, and the two side surfaces of the wedge-shaped head 411 are respectively slidably connected with the two slopes 341, and the wedge head 411 can drive the two spreading pieces 340 to open and close with each other. Among them, through the cooperation of the two side surfaces of the wedge-shaped head 411 and the two slopes 341, the two spreading pieces 340 can be opened and closed with each other, and the whole movement is not easy to get stuck.

[0038] In a specific embodiment, an inverted T-shaped groove 342 is formed on the two slope surfaces 341 , and a clamping head 412 matching with the inverted T-shaped groove 342 is formed on both side surfaces of the wedge-shaped head 411 .

[0039] Of course, in an improved embodiment, the two opening pieces 340 may be connected via a return spring, so that the two side surfaces of the wedge-shaped head 411 and the two slope surfaces 341 may be slidably connected to achieve the above-mentioned opening and closing action.

[0040] See also Figure 6 In an improved embodiment of the present application, in order to simplify the structure, magnetic blocks 343 are provided in both of the two slopes 341, and sliding pieces 413 cooperating with the magnetic blocks 343 are provided on both sides of the wedge-shaped head 411. The sliding piece 413 is a detachable structure, which is convenient for later replacement, and the two open pieces 340 can be retracted by magnetic adsorption.

[0041] See also Figures 4 to 6 In one embodiment of the present application, in order to make the connection between the two stretching pieces 340 tighter and facilitate the winding of the pole piece and the diaphragm, the two stretching pieces 340 are alternately provided with sliding grooves 344 and sliding tongues 345 on the opposite sides. The sliding tongue 345 on one of the stretching pieces 340 can be slidably installed in the sliding groove 344 of the other stretching piece 340. Such an arrangement allows the two stretching pieces 340 to be arranged in parallel to maintain overall consistency, which is conducive to ensuring that the wound battery cell can maintain overall consistency and reduce the influence of the force acting on the pole piece and the diaphragm during winding.

[0042] In actual use, the winding device also needs to cooperate with the pole piece feeding, diaphragm feeding, cutting assembly and other mechanisms to jointly realize the winding of the battery cell. Therefore, when the pole piece feeding and diaphragm feeding respectively transport the pole piece and the diaphragm to one side of the two said opening pieces 340, in order to enable the two said opening pieces 340 to drive the ends of the pole piece and the diaphragm to rotate around themselves, an external pressing needle can be used to cooperate with the two opening pieces 340 to clamp the ends of the pole piece and the diaphragm. However, such a structure requires the addition of an external mechanism. For this reason, in an improved embodiment of the present application, see further Figure 5 The telescopic end of the spreading mechanism 400 is connected to the driving head 410 through a driving buffer assembly 500. A clamping needle 510 is provided at one end of the driving buffer assembly 500 facing the driving head 410. The telescopic end of the spreading mechanism 400 can drive the clamping needle 510 and the driving head 410 to move outward in turn, so that the clamping needle 510 gradually approaches the two spreading pieces 340 and cooperates with the two spreading pieces 340 to clamp the ends of the battery pole pieces and gradually opens the two spreading pieces 340.

[0043] In this embodiment, by providing the driving buffer assembly 500, when the opening mechanism 400 drives the driving head 410 to open the two opening pieces 340, the clamping needle 510 can be synchronously driven to gradually approach the two opening pieces 340 to clamp the ends of the pole piece and the diaphragm, which is conducive to the two opening pieces 340 driving the pole piece and the diaphragm to be wound. It should be noted that in this embodiment, due to the provision of the driving buffer assembly 500, during the process of extending the telescopic end of the opening mechanism 400, the clamping needle 510 is sequentially driven to first approach the two opening pieces 340, and then the driving head 410 is driven to open the two opening pieces 340.

[0044] See also Figure 7 and Figure 8In an improved embodiment of the present application, in order to realize the above-mentioned sequential linkage, the driving buffer assembly 500 includes a connecting rod 520 and a movable cylinder 530, one end of the connecting rod 520 is movably inserted in one end of the movable cylinder 530, the other end of the connecting rod 520 is movably plugged with the end of the driving head 410 away from the outside, the other end of the movable cylinder 530 is connected to the telescopic end of the expansion mechanism 400, the connecting rod 520 is movably sleeved with a first spring 540, the movable cylinder 530 is provided with a second spring 550, and the second spring 550 is The two ends are respectively connected to the bottom of the movable cylinder 530 and the end face of the connecting rod 520, the connecting rod 520 is movably sleeved with a movable sleeve 560, and the clamping needle 510 is provided on the end of the movable sleeve 560 facing the driving head 410. One end of the first spring 540 is connected to the side surface corresponding to the driving head 410, and the other end is connected to the end face of the movable sleeve 560 to abut the other side surface of the movable sleeve 560 against the end face of the corresponding end of the movable cylinder 530. The stiffness coefficient of the second spring 550 is much larger than the stiffness coefficient of the first spring 540.

[0045] Among them, the stiffness coefficient of the second spring 550 is much greater than the stiffness coefficient of the first spring 540. The main purpose of this arrangement is that when the telescopic end of the expansion mechanism 400 extends to drive the movable cylinder 530 close to the connecting rod 520, the first spring 540 is compressed first, and the movable sleeve 560 is gradually forced to approach the driving head 410, thereby also making the clamping needle 510 gradually approach the two expansion pieces 340, and then can cooperate with the expansion pieces 340 to clamp the end of the pole piece and the diaphragm. In the present application, when the clamping needle 510 is fully in place, the first spring 540 is in a fully compressed state.

[0046] When the telescopic end of the expansion mechanism 400 continues to extend, the second spring 550 begins to be compressed, and then starts to drive the drive head 410 to expand the two expansion pieces 340 until the two expansion pieces 340 are expanded to a preset width, and then winding can begin. If the tightness of the winding of the pole piece and the diaphragm needs to be adjusted during the winding process, the expansion mechanism 400 only needs to continue to extend appropriately. At this time, because the first spring 540 has been completely compressed, it will not affect the relative position of the clamping needle 510 relative to the two expansion pieces 340, thereby ensuring the quality of the winding of the pole piece and the diaphragm. In addition, the buffering effect of the second spring 550 also enables the winding center formed by the two expansion pieces 340 and the rolling tongue piece 330 to withstand the impact from the pole piece and the diaphragm during the winding process, and also to a certain extent avoids the expansion mechanism 400 from extending too much and causing damage to the already wound pole piece and diaphragm, thereby playing a buffering and protective role.

[0047] In the above-mentioned embodiment, due to long-term use, the clamping pin 510 will be deformed, which will cause the clamping force between it and the two opening pieces 340 to decrease. In order to facilitate adjustment, in an improved embodiment of the present application, an adjustment member 570 is provided on the movable sleeve 560, and the adjustment member 570 can adjust the inclination angle of the clamping pin 510 relative to the structure composed of the two opening pieces 340. It should be noted that the clamping pin 510 is V-shaped with a large angle as a whole, which is conducive to adjusting the elasticity. The adjustment member 570 is a nut in the present application.

[0048] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An electrode sheet winding device, characterized in that: include A revolution mechanism, which is capable of rotating on itself; A winding mechanism, which is provided with at least two groups and is respectively arranged on the revolution mechanism, and the output end of the winding mechanism can rotate; At least two groups of winding mechanisms, each comprising a mounting seat, a first retractor arranged on the mounting seat, and a tongue-rolling piece installed on the output end of the first retractor, each mounting seat being installed on the output end of the corresponding winding mechanism, and a pair of opening pieces capable of opening and closing with each other are arranged on the outward end of the tongue-rolling piece; At least two groups of spreading mechanisms are respectively installed on the output end of each of the winding mechanisms. Each of the spreading mechanisms is provided with a retractable driving head. The driving head moves through the rolling tongue piece and is slidably engaged with the inner sides opposite to the two spreading pieces. The driving head can drive the two spreading pieces to open and close each other.

2. The electrode sheet winding device according to claim 1, characterized in that: A slope is provided on one end of the inner side of the two spreading pieces close to the rolling tongue piece, and the slopes on the two spreading pieces are arranged in a trumpet shape. A wedge-shaped head is provided on the outward end of the driving head, and the two side surfaces of the wedge-shaped head are respectively slidably connected to the two slopes. The wedge-shaped head can drive the two spreading pieces to open and close each other.

3. The electrode sheet winding device according to claim 2, characterized in that: The two slope surfaces are provided with inverted T-shaped grooves, and the two side surfaces of the wedge-shaped head are provided with clamping heads matched with the inverted T-shaped grooves.

4. The electrode sheet winding device according to claim 2, characterized in that: Magnetic blocks are arranged in the two slope surfaces, and sliding sheets cooperating with the magnetic blocks are arranged on the two side surfaces of the wedge-shaped head.

5. The electrode sheet winding device according to claim 1, characterized in that: Slide grooves and slide tongues are alternately arranged on the opposite sides of the two expansion pieces, and the slide tongue on one expansion piece can be slidably installed in the slide groove of the other expansion piece.

6. An electrode sheet winding device according to any one of claims 1 to 5, characterized in that: The telescopic end of the spreading mechanism is connected to the driving head through a driving buffer assembly. A clamping needle is provided at one end of the driving buffer assembly facing the driving head. The telescopic end of the spreading mechanism can drive the clamping needle and the driving head to move outward in turn, so that the clamping needle gradually approaches the two spreading pieces and cooperates with the two spreading pieces to clamp the ends of the battery pole pieces and makes the two spreading pieces gradually open.

7. The electrode sheet winding device according to claim 6, characterized in that: The driving buffer assembly includes a connecting rod and a movable cylinder, one end of the connecting rod is movably inserted in one end of the movable cylinder, the other end of the connecting rod is movably inserted with the end of the driving head away from the outside, the other end of the movable cylinder is connected to the telescopic end of the expansion mechanism, the connecting rod is movably sleeved with a first spring, a second spring is arranged in the movable cylinder, the two ends of the second spring are respectively connected with the bottom of the movable cylinder and the end face of the connecting rod, the connecting rod is movably sleeved with a movable sleeve, the clamping needle is arranged on the end of the movable sleeve facing the driving head, one end of the first spring is connected to the side surface corresponding to the driving head, and the other end is connected to the end face of the movable sleeve so that the other side surface of the movable sleeve abuts against the end face of the corresponding end of the movable cylinder, and the stiffness coefficient of the second spring is much larger than the stiffness coefficient of the first spring.

8. The electrode sheet winding device according to claim 7, characterized in that: The movable sleeve is provided with an adjusting member, and the adjusting member can adjust the inclination angle of the clamping needle relative to the structure composed of the two spreading sheets.

9. The electrode sheet winding device according to claim 1, characterized in that: The winding mechanism includes a rotating flange, an outer gear ring arranged on one end of the rotating flange, and a driving motor arranged on the revolution mechanism. The rotating flange can be rotatably installed in the rotating hole of the revolution mechanism, and the output end of the driving motor is meshed with the outer gear ring through a gear. The mounting seat and the spreading mechanism are both installed on the rotating flange, and the rolling tongue piece moves through the through hole on the rotating flange and is placed on the other side of the revolution mechanism.

10. The electrode sheet winding device according to claim 9, characterized in that: The expansion mechanism comprises a base and a second retractor arranged on the base, an output end of the second retractor is connected to the driving head, and the base is mounted on a rotating flange.

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