Winding device and winding method

Abstract

The invention relates to a winding device and a winding method. The winding device comprises an unwinding mechanism, a buffering mechanism, a main driving mechanism, a tension control mechanism and a winding mechanism. The unreeling mechanism unreels a roll material, the roll material passes through the cache mechanism, a first electronic cam in the cache mechanism adjusts the cache length of the roll material, then the roll material passes through the main driving mechanism and the tension control mechanism, and tension control is conducted by a second electronic cam and / or a third electronic cam in the tension control mechanism. And finally, winding at the winding mechanism to form a winding core. According to the invention, active control on tension and active control on speed are realized, the risk that the winding core wrinkles and breaks the belt is reduced, and the winding efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a winding device and winding method. Background Technology

[0002] Electrode assemblies for battery cells generally include two methods: winding and lamination. Currently, for winding, with the increasing demands for winding speed, large fluctuations in tension and speed occur at high speeds, easily leading to PID control lag. This results in substandard core overhang, as well as quality problems such as separator wrinkling, electrode wrinkling, and electrode strip breakage. Although many optimizations have been made to the PID closed-loop control algorithm, the efficiency bottleneck still cannot be overcome, resulting in high equipment investment costs. Summary of the Invention

[0003] This application provides a winding device and a winding method to solve or at least improve the problems in the above-mentioned background art, realize active control of tension and active control of speed, avoid the lag of the traditional PID control method, and improve the winding quality of the core.

[0004] The present invention provides a winding device comprising, from upstream to downstream: an unwinding mechanism for unwinding a roll of material; a buffer mechanism for buffering the roll of material; the buffer mechanism including at least one fixed roller and a first electronic cam, the first electronic cam being configured to move to adjust the buffer length of the roll of material; a main drive mechanism for driving the roll of material downstream; a tension control mechanism including at least one fixed roller and a second electronic cam, the second electronic cam being configured to move to adjust the tension of the roll of material; and a winding mechanism for winding the roll of material.

[0005] Furthermore, the tension control mechanism also includes a third electronic cam configured to move in conjunction with the second electronic cam to adjust the tension of the roll.

[0006] Furthermore, the first electronic cam includes a first moving roller and a first driver, the first driver being used to drive the first moving roller to move to change its position; and / or, the second electronic cam includes a second moving roller and a second driver, the second driver being used to drive the second moving roller to move to change its position; and / or, the third electronic cam includes a third moving roller and a third driver, the third driver being used to drive the third moving roller to move to change its position.

[0007] Furthermore, the first driver, the second driver, and the third driver are all linear motors.

[0008] Furthermore, the buffer mechanism has multiple fixed rollers, and along the conveying direction of the roll, the first electronic cam is disposed between two adjacent fixed rollers.

[0009] Furthermore, the tension control mechanism has multiple fixed rollers, and along the conveying direction of the roll, the second electronic cam is disposed between two adjacent fixed rollers, and the third electronic cam is disposed between two adjacent fixed rollers.

[0010] Furthermore, a spring roller is also provided between the main drive mechanism and the tension control mechanism.

[0011] Furthermore, a tension detection mechanism is also provided downstream of the tension control mechanism.

[0012] Furthermore, the rolled material is a positive electrode sheet, a negative electrode sheet, or a separator.

[0013] The present invention also provides a winding method, wherein the winding method is performed using the winding device described in any of the above technical solutions, and the winding method includes: step S1, establishing a cam position and tension comparison table according to the position of the second electronic cam; setting the tension required for each turn of the core winding according to the core winding process requirements; step S2, establishing a first correspondence between the number of turns and the position of the second electronic cam according to the tension required for each turn and the comparison table; step S3, setting the position of the first electronic cam per turn according to the first correspondence, thereby establishing a second correspondence between the number of turns and the position of the first electronic cam; step S4, performing a winding operation according to the first correspondence and the second correspondence.

[0014] Furthermore, the tension control mechanism also includes a third electronic cam; step S1 includes: establishing a cam position-tension lookup table based on the positions of the second and third electronic cams; step S2 includes: establishing a first correspondence between the number of turns and the positions of the second and third electronic cams based on the tension required per turn and the lookup table.

[0015] Furthermore, in step S1, establishing the cam position and tension comparison table includes: step S10, dividing the stroke of the second electronic cam into n equal parts to obtain multiple positions of the second electronic cam; dividing the stroke of the third electronic cam into m equal parts to obtain multiple positions of the third electronic cam; step S11, matching the positions of the second electronic cam and the positions of the third electronic cam in pairs, and setting the corresponding tension.

[0016] Furthermore, the winding device also includes a tension detection mechanism, which is used to detect the actual tension and compare it with the tension required by the core for each turn of winding to determine whether the two are consistent.

[0017] Furthermore, the first and second correspondences are optimized and adjusted through AI self-learning.

[0018] This application pre-sets the position of each electronic cam during each turn of the winding core according to the required tension for each turn. During each turn of winding, the movement of each electronic cam is controlled according to the pre-set position, so that it moves to the set position. This achieves active control of tension and active control of speed, avoids the lag in the traditional PID control method, reduces the risk of core wrinkling and breakage, and improves winding efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a winding device according to an embodiment of this application.

[0020] Figure 2 This is a flowchart of a winding method according to an embodiment of this application. Detailed Implementation

[0021] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, inside, outside, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0024] In the description of this invention, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some implementations," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this invention.

[0025] This application provides a winding device and a winding method.

[0026] See Figure 1The winding device of this application is provided in sequence from upstream to downstream as follows: an unwinding mechanism 10 for unwinding the roll material; a buffer mechanism 20 for buffering the roll material; a main drive mechanism 30 for driving the roll material to be conveyed downstream; a tension control mechanism 40 for adjusting the tension of the roll material; and a winding mechanism 50 for winding the roll material.

[0027] In one specific embodiment, the rolled material is an electrode sheet or a separator. When used to manufacture a core for a battery cell, the unwinding mechanism 10, the buffer mechanism 20, the main drive mechanism 30, and the tension control mechanism 40 each include multiple components. Generally, the winding structure of the core is an upper separator, a positive electrode sheet, a lower separator, and a negative electrode sheet. Therefore, there are four unwinding mechanisms 10, four buffer mechanisms 20, four main drive mechanisms 30, and four tension control mechanisms 40. The upper separator, the positive electrode sheet, the lower separator, and the negative electrode sheet are each unwound by their respective unwinding mechanisms 10, and then pass through the buffer mechanism 20, the main drive mechanism 30, and the tension control mechanism 40 in sequence. Finally, they are wound at the same winding mechanism 50, thereby winding the upper separator, the positive electrode sheet, the lower separator, and the negative electrode sheet into a core. It can be understood that... Figure 1 Only one set of unwinding mechanism 10, buffer mechanism 20, main drive mechanism 30 and tension control mechanism 40 is shown as an example, and winding mechanism 50 is shown. The winding mechanism 50 overlaps the upper diaphragm, positive electrode sheet, lower diaphragm and negative electrode sheet unwound by the four unwinding mechanisms 10 respectively and winds them into a core.

[0028] Specifically, the unwinding mechanism 10 of this application includes an unwinding roller 11 for unwinding the electrode sheet or diaphragm.

[0029] The buffer mechanism 20 includes at least one fixed roller and a first electronic cam 21. For example, it has three fixed rollers: a first fixed roller 221, a second fixed roller 222, and a third fixed roller 223. Along the transport direction of the roll, the first electronic cam 21 is positioned between adjacent second fixed rollers 222 and third fixed rollers 223. That is, the buffer mechanism 20 is sequentially arranged with the first fixed roller 221, the second fixed roller 222, the first electronic cam 21, and the third fixed roller 223 along the transport direction of the roll. The positions of the first fixed roller 221, the second fixed roller 222, the first electronic cam 21, and the third fixed roller 223 allow for changes in the transport path of the roll. Furthermore, the first electronic cam 21 is configured to move to adjust the buffer length of the roll.

[0030] In one specific embodiment, the first electronic cam 21 includes a first movable roller 210 and a first driver (not shown). The first driver is used to drive the first movable roller 210 to move according to control commands to change its position. For example, the first driver is a linear motor, so the first movable roller 210 can move along a first direction D1 under the drive of the linear motor. Therefore, during the movement of the first movable roller 210 along the first direction D1, the distance between it and the second fixed roller 222 and the third fixed roller 223 can be changed, thereby realizing the adjustment of the roll buffer length.

[0031] The main drive mechanism 30 includes a pair of drive wheels that provide the main power for conveying the roll material downstream.

[0032] The tension control mechanism 40 includes a second electronic cam 42, a third electronic cam 43, and at least one fixed roller. For example, it has four fixed rollers: a fourth fixed roller 441, a fifth fixed roller 442, a sixth fixed roller 443, and a seventh fixed roller 444. Along the transport direction of the coil, the second electronic cam 42 is positioned between adjacent fourth fixed rollers 441 and fifth fixed rollers 442, and the third electronic cam 43 is positioned between adjacent sixth fixed rollers 443 and seventh fixed rollers 444. That is, the tension control mechanism 40 sequentially includes the fourth fixed roller 441, the second electronic cam 42, the fifth fixed roller 442, the sixth fixed roller 443, the third electronic cam 43, and the seventh fixed roller 444 along the transport direction of the coil. The fourth fixed roller 441, the second electronic cam 42, the fifth fixed roller 442, the sixth fixed roller 443, the third electronic cam 43, and the seventh fixed roller 444 are positioned such that the conveying path of the roll can be changed, and the second electronic cam 42 and the third electronic cam 43 are both configured to move to adjust the tension of the roll.

[0033] In one specific embodiment, the second electronic cam 42 includes a second moving roller 420 and a second driver (not shown), the second driver being used to drive the second moving roller 420 to move and change its position according to control commands; the third electronic cam 43 includes a third moving roller 430 and a third driver (not shown), the third driver being used to drive the third moving roller 430 to move and change its position according to control commands. Exemplarily, both the second and third drivers are linear motors, so the second moving roller 420 can move along a second direction D2 under the drive of the linear motor; the third moving roller 430 can move along a third direction D3 under the drive of the linear motor. Therefore, during the movement of the second moving roller 420 along the second direction D2 and / or the third moving roller 430 along the third direction D3, the distance between the second moving roller 420 and the third moving roller 430 along the roll material transport direction can be changed, thereby achieving adjustment of the roll material tension. In this embodiment, the second direction D2 and the third direction D3 can be set to be parallel, thereby improving tension adjustment efficiency. Of course, in some other embodiments, the second direction D2 and the third direction D3 can also be set to form a certain angle, which does not depart from the essence of this application.

[0034] As can be understood, electronic cams use constructed cam curves to simulate mechanical cams. They directly input the trajectory points into the driver and perform servo control through a set program. Therefore, electronic cams are usually controlled by a controller.

[0035] The winding mechanism 50 includes a winding needle for winding the electrode sheet and the diaphragm.

[0036] When the winding device of this embodiment is working, the unwinding mechanism 10 unwinds the electrode sheet or diaphragm. The electrode sheet or diaphragm passes through the buffer mechanism 20. The first electronic cam 21 in the buffer mechanism 20 is controlled by a linear motor to adjust the buffer length of the electrode sheet or diaphragm. Then the electrode sheet or diaphragm passes through the main drive mechanism 30 and then through the tension control mechanism 40. The tension is controlled by the second electronic cam 42 and the third electronic cam 43. Finally, it is wound into a core at the winding mechanism 50.

[0037] See Figure 2 Accordingly, the winding method of this application includes the following steps, which avoids the lag of feedback control through active control, so as to improve the winding quality.

[0038] Step S1: Establish a cam position and tension comparison table based on the positions of the second electronic cam 42 and the third electronic cam 43; set the required tension of the core during each turn of winding according to the core winding process requirements.

[0039] In one specific embodiment, the strokes of the second electronic cam 42 and the third electronic cam 43 are divided into n and m equal parts, respectively; then, the positions of the second electronic cam 42 and the third electronic cam 43 are matched pairwise, and the corresponding tension F is set. 11 The value of Fnm is used to create a table showing the relationship between cam position and tension, as shown below. The tension corresponding to the cam position can be obtained through theoretical calculations, computer simulations, or experimental measurements.

[0040]

[0041] Step S2: Based on the tension required for each winding and the cam position and tension comparison table, establish a first correspondence between the number of windings and the positions of the second and third electronic cams.

[0042] Once the required tension for each turn is set, the corresponding cam position is obtained by consulting a cam position-tension lookup table, thus obtaining the second and third electronic cam positions. For example, if the required tension for a certain turn of winding is set to F, the tension F and F... 25 If they are the same, it means that during this turn of winding, the second electronic cam 42 should be in position 2 and the third electronic cam 43 should be in position 5.

[0043] Step S3: Based on the first correspondence, set the position of the first electronic cam 21 per revolution, thereby establishing a second correspondence between the number of revolutions and the position of the first electronic cam.

[0044] Since the length of the coil between the second electronic cam 42 and the third electronic cam 43 changes during their movement, the feeding of the coil needs to be adjusted accordingly. Therefore, in this step, the position of the first electronic cam 21 is adaptively set according to the position changes of the second electronic cam 42 and the third electronic cam 43 to adjust the buffer length of the coil to adapt to the tension adjustment and to match the speed changes during the winding process, thereby achieving speed control.

[0045] In one specific implementation, when winding a specific battery cell, a correspondence between the positions of the second electronic cam 42 and the third electronic cam 43 and the position of the first electronic cam 21 can be established in advance to form a reference table. Based on the positions of the second electronic cam 42 and the third electronic cam 43, the position of the first electronic cam 21 can be obtained, and the position of the first electronic cam 21 per revolution can be set according to the first correspondence.

[0046] Step S4: Perform a winding operation according to the first correspondence and the second correspondence.

[0047] Specifically, at the beginning of each winding, based on the first correspondence between the number of windings and the positions of the second and third electronic cams, and the second correspondence between the number of windings and the position of the first electronic cam, the controller controls the first electronic cam 21, the second electronic cam 42, and the third electronic cam 43 to move to the desired positions. That is, the linear motor drives the first moving roller 210, the second moving roller 420, and the third moving roller 430 to the desired positions. The linear motor operates according to a pre-set program through the controller.

[0048] It is understood that at the beginning of each winding, the controller controls the first electronic cam 21, the second electronic cam 42 and the third electronic cam 43 to move to the required position, including keeping the positions of the first electronic cam 21, the second electronic cam 42 and the third electronic cam 43 unchanged.

[0049] In one specific embodiment, the tension of the first 1 to 20 turns of the winding core is set as the first tension, for example, 200 gf, and the tension of the 21st to 30th turns is set as the second tension, for example, 300 gf. Based on the required tension and referring to the cam position and tension lookup table, the first cam positions of the second electronic cam 42 and the third electronic cam 43 for the first 1 to 20 turns, and the second cam positions of the second electronic cam 42 and the third electronic cam 43 for the 21st to 30th turns are obtained accordingly. Furthermore, based on the change from the first cam position to the second cam position, by looking up the pre-established lookup table between the positions of the second electronic cam 42 and the third electronic cam 43 and the position of the first electronic cam 21, the first electronic cam 21 is set to move from the original first buffer position to the second buffer position to adjust the buffer length and control the winding speed to adapt to the change in cam position. Based on the above settings, during the winding operation, the positions of the first electronic cam 21, the second electronic cam 42, and the third electronic cam 43 remain unchanged during the first to 20 turns of the winding core. At the beginning of the 21st turn, the first electronic cam 21 is moved from the first buffer position to the second buffer position, for example, see [reference needed]. Figure 1 A linear motor moves the first moving roller 210 to the left, while simultaneously moving the second electronic cam 42 and the third electronic cam 43 from the first cam position to the second cam position. For example, a linear motor moves the second moving roller 420 upward and the third moving roller 430 downward. This movement of the second and third moving rollers 420 increases the distance between them along the winding direction, thereby increasing tension to accommodate tension adjustments from 200gf to 300gf. Simultaneously, the leftward movement of the first moving roller 210 reduces the buffer length of the winding, releasing more material. This, combined with the movements of the second and third moving rollers 420 and 430, matches the speed variations during winding.

[0050] It should be noted that the above embodiments are merely exemplary descriptions. In actual winding, for each turn, a conventional approach is to calculate the corresponding winding length according to the Archimedes spiral formula, and combine it with the length encoder to determine whether it is within the corresponding number of turns, and then set the required tension for each turn, thereby controlling the positions of the first electronic cam 21, the second electronic cam 42 and the third electronic cam 43 accordingly.

[0051] Therefore, based on the tension required for each winding, the positions of the first electronic cam 21, the second electronic cam 42, and the third electronic cam 43 are pre-set during each winding of the core. During winding, the first electronic cam 21, the second electronic cam 42, and the third electronic cam 43 are adjusted according to the pre-set positions, thereby achieving active control of tension and active control of speed. This avoids the lag in the traditional PID control method, reduces the risk of core wrinkling and breakage, and improves winding efficiency.

[0052] It should be noted that, in this embodiment of the application, since the movement of the electronic cam is ultimately presented through the movement trajectory of the moving roller, the position of the electronic cam can be considered as the position of its corresponding moving roller.

[0053] In addition, since electronic cams are flexible and their trajectories are easy to modify, allowing for convenient changes to the trajectory as needed, the winding device and winding method of this application can be applied to winding various types of battery cells, such as prismatic cells, cylindrical cells, and cells of different sizes, thus having wider applicability.

[0054] In another specific embodiment, the tension control mechanism 40 includes a fixed roller and an electronic cam, i.e., only a second electronic cam 42 or a third electronic cam 43 is provided. For example, only the second electronic cam 42 is provided, without the third electronic cam 43. Since the second electronic cam 42 itself can be controlled and moved to different positions by the controller, the distance between it and the fixed roller can also be adjusted, thereby adjusting the tension of the coil.

[0055] Specifically, in this embodiment, the corresponding winding method includes: establishing a cam position-tension lookup table based on the position of the second electronic cam 42; wherein the specific method for establishing the cam position-tension lookup table is the same as the logic of the embodiment described above, and will not be repeated here. Simultaneously, according to the core winding process requirements, the tension required for each turn of the core is set. Based on the tension required for each turn and the lookup table, a first correspondence between the number of turns and the position of the second electronic cam is established. Based on the first correspondence, the position of the first electronic cam per turn is set, thereby establishing a second correspondence between the number of turns and the position of the first electronic cam. Finally, the winding operation is performed according to the first and second correspondences.

[0056] It can also be understood that when the tension control mechanism 40 is equipped with a second electronic cam 42 and a third electronic cam 43, it has a larger tension adjustment range and higher adjustment accuracy because it has two electronic cams and their positions can be controlled by the controller.

[0057] Furthermore, the winding device of this application also includes a tension detection mechanism 60, which is located downstream of the tension control mechanism 40. The tension detection mechanism 60 is used to detect the actual tension and compare it with the set value (i.e., the set tension required by the core for each turn of winding) to determine whether the two are consistent.

[0058] After performing a sufficient number of winding operations or having a sufficient number of samples, the winding method of this application can, based on AI self-learning, fine-tune the first correspondence and / or the second correspondence before the start of the next core winding, thereby optimizing the control of the coil tension, buffer length and speed, and ultimately producing cores with extremely high consistency at the winding mechanism.

[0059] In other words, in the winding method of this application, the first correspondence and the second correspondence can be continuously iterated and optimized through AI self-learning.

[0060] In addition, the winding device of this application may also be provided with a spring roller 70 between the main drive mechanism 30 and the tension control mechanism 40, that is, a fixed roller is connected by a spring. The spring deforms due to the tension of the winding material and changes its deformation according to the change of tension. Therefore, the spring roller 70 can ensure that the winding material is always in a taut state.

[0061] Finally, it is understood that the winding apparatus and winding method of this application can be applied not only to the winding process of battery cells, but also to processes involving tension adjustment and control, such as electrode coating, without departing from the protection scope of this application.

[0062] It should be noted that although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A winding device, characterized in that, From upstream to downstream, the following are installed sequentially: Unwinding mechanism, used for unwinding coiled material; A buffer mechanism for buffering the roll material; the buffer mechanism includes at least one fixed roller and a first electronic cam, the first electronic cam being configured to move to adjust the buffer length of the roll material; The main drive mechanism is used to drive the coil material to be conveyed downstream; The tension control mechanism includes at least one fixed roller and a second electronic cam, the second electronic cam being configured to move to adjust the tension of the roll; And a winding mechanism for winding the roll.

2. The winding device according to claim 1, characterized in that, The tension control mechanism further includes a third electronic cam configured to move in conjunction with the second electronic cam to adjust the tension of the roll.

3. The winding device according to claim 2, characterized in that, The first electronic cam includes a first movable roller and a first driver, the first driver being used to drive the first movable roller to move in order to change its position; And / or, the second electronic cam includes a second moving roller and a second driver, the second driver being used to drive the second moving roller to move to change its position; And / or, the third electronic cam includes a third moving roller and a third driver, the third driver being used to drive the third moving roller to move to change its position.

4. The winding device according to claim 1, characterized in that, The buffer mechanism has multiple fixed rollers, and along the conveying direction of the roll, the first electronic cam is disposed between two adjacent fixed rollers.

5. The winding device according to claim 2, characterized in that, The tension control mechanism has multiple fixed rollers. Along the conveying direction of the roll, the second electronic cam is disposed between two adjacent fixed rollers, and the third electronic cam is disposed between two adjacent fixed rollers.

6. The winding device according to claim 1, characterized in that, A spring roller is also provided between the main drive mechanism and the tension control mechanism.

7. The winding apparatus according to any one of claims 1-6, characterized in that, A tension detection mechanism is also provided downstream of the tension control mechanism.

8. A winding method, wherein the winding method is performed using a winding apparatus as described in any one of claims 1-7, characterized in that, The winding method includes: Step S1: Based on the position of the second electronic cam, establish a cam position and tension comparison table; based on the core winding process requirements, set the tension required for each turn of the core during winding. Step S2: Based on the tension required for each winding and the reference table, establish a first correspondence between the number of turns and the position of the second electronic cam; Step S3: Based on the first correspondence, set the position of the first electronic cam per revolution, thereby establishing a second correspondence between the number of revolutions and the position of the first electronic cam; Step S4: Perform a winding operation according to the first correspondence and the second correspondence.

9. The winding method according to claim 8, characterized in that, The tension control mechanism also includes a third electronic cam; Step S1 includes: establishing a cam position and tension comparison table based on the second electronic cam position and the third electronic cam position; Step S2 includes: establishing a first correspondence between the number of turns and the positions of the second and third electronic cams based on the tension required for each turn and the reference table.

10. The winding method according to claim 9, characterized in that, In step S1, establishing the cam position and tension comparison table includes: Step S10: Divide the stroke of the second electronic cam into n equal parts to obtain multiple positions of the second electronic cam; divide the stroke of the third electronic cam into m equal parts to obtain multiple positions of the third electronic cam. Step S11: Match the positions of the second electronic cam and the third electronic cam in pairs, and set the corresponding tension.

11. The winding method according to any one of claims 8-10, characterized in that, The winding device also includes a tension detection mechanism, which is used to detect the actual tension and compare it with the tension required for each turn of the winding core to determine whether the two are consistent.

12. The winding method according to claim 11, characterized in that, The first and second correspondences are optimized and adjusted through AI self-learning.

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