A lithium battery pole piece automatic punching device and method

Abstract

The present invention relates to the field of battery pole piece manufacturing control technology, and specifically to an automatic punching device and method for lithium battery pole pieces. The device is provided with a fixed roller and a movable roller after the extruded disc cutter body. After the pole piece is punched by the disc cutter body, two pole pieces are formed, which will pass through the fixed roller and the movable roller. The movable roller is connected to a spring so that it can move due to the pressure of the pole piece. The pressure sensor at the other end of the spring is used to collect the pressure signal of the pole piece in this direction. The data processing module is used to determine the surface undulation degree and the pressure distribution skewness according to the data distribution on the pressure signal, and then determine the defect probability and accurately adjust the overlap amount of the tool according to the defect probability and the deflection direction. The present invention can ensure the quality of the pole piece in the subsequent punching process by detecting the pole piece morphology and adaptively adjusting the overlap amount, avoiding the occurrence of a large number of low-quality pole pieces, and ensuring the quality of the finished product.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pole piece manufacturing control, and in particular to an automatic punching device and method for lithium battery pole pieces. Background Art

[0002] Pole piece production is a basic process for making lithium batteries. Pole piece punching can be used to divide the rolled battery pole pieces into strips according to the battery specifications. In the prior art, the principle of pole piece disc cutting is often used. The pole pieces are sheared by the upper and lower knife discs on the disc cutter device to form two strips of punched pole piece materials. In the process of the disc cutter cutting the pole piece, it is mainly through the contact point formed by the bite of the tool that the pole piece contacts the pole piece, and then the pole piece receives the pressure of the upper and lower knife discs and produces elastic deformation, so that the pole piece material is bent and sheared. Therefore, the overlap between the upper and lower knife discs is an important parameter in the pole piece punching process. If the overlap is not appropriate, the cut pole piece will have wavy edges, which will affect the dimensional accuracy and appearance quality of the battery, and affect the final thickness and morphology of the battery. Therefore, if the overlap of the tool is not effectively controlled, the generation of wavy edges cannot be avoided, resulting in a large number of defects in the punched material, resulting in product quality defects or cost waste. Summary of the invention

[0003] In order to solve the technical problem that the overlap amount of the tool cannot be effectively controlled in the prior art, the purpose of the present invention is to provide a lithium battery pole piece automatic punching device and method, and the technical solution adopted is as follows:

[0004] The present invention proposes an automatic punching device for lithium battery pole pieces, comprising a disc cutter body, the disc cutter body comprising two cutter discs, the device being respectively equipped with a fixed roller and a movable roller in two directions of conveying the pole piece after the two cutter discs cut; the movable roller is moved on a spring under the pressure of the pole piece, one end of the spring is connected to the movable roller, and the other end is connected to a fixed pressure sensor; the pressure sensor is used to collect in real time the pressure signal fed back by the movable roller when the pole piece is conveyed between the fixed roller and the movable roller; the device also comprises a data processing module, the data processing module receives the pressure signal and analyzes it, determines the defect probability of the pole piece generating a wavy edge, and adjusts the overlap amount of the two cutter discs in the disc cutter body according to the defect probability;

[0005] The data processing method of the data processing module includes:

[0006] In real time, the surface undulation degree of the pole piece is determined according to the fluctuation degree and pressure value of the pressure signal; the local pressure distribution skewness of each maximum point is determined according to the coordinate distribution between the maximum point and the adjacent minimum point on the pressure signal; the overall skewness and deflection direction of the pole piece are obtained according to the pressure distribution skewness of each maximum point; the defect probability is determined according to the surface undulation degree and the overall skewness; the adjustment direction of the overlap amount is determined according to the deflection direction, the adjustment amount of the overlap amount is determined according to the defect probability, and an overlap amount control signal is sent to the disc cutter body.

[0007] Furthermore, the method for obtaining the surface undulation degree includes:

[0008] The average pressure value of the pressure signal is taken as the overall pressure value, and the variance is taken as the pressure fluctuation feature; the ratio of the overall pressure value to the standard pressure value is taken as the first contrast feature, and the ratio of the pressure fluctuation feature to the standard pressure fluctuation feature is taken as the second contrast feature; the surface undulation degree is obtained according to the first contrast feature and the second contrast feature.

[0009] Furthermore, the method for obtaining the standard pressure value and the standard pressure fluctuation characteristic includes:

[0010] The moment when the electrode begins to be punched is taken as the starting moment, and all pressure signals between the starting moment and the real time moment are spliced ​​to obtain an overall pressure signal; the average pressure value of the overall pressure signal is taken as the standard pressure value, and the variance is taken as the standard pressure fluctuation characteristic.

[0011] Furthermore, the method for obtaining the pressure distribution skewness includes:

[0012] For each maximum point on the pressure signal, the minimum point closest to the left in time sequence is taken as the first minimum point, and the minimum point closest to the right in time sequence is taken as the second minimum point; the first time sequence difference and the first pressure difference between the maximum point and the first minimum point are obtained; the second time sequence difference and the second pressure difference between the maximum point and the second minimum point are obtained; the ratio of the first pressure difference to the first time sequence difference is taken as the first change feature, and the ratio of the second pressure difference to the second time sequence difference is taken as the second change feature; the difference between the first change feature and the second change feature is taken as the pressure distribution skewness feature of the maximum point.

[0013] Furthermore, the overall skewness is the average of the absolute values ​​of the pressure distribution skewness of all maximum points on the pressure signal.

[0014] Furthermore, the method for obtaining the deflection direction includes:

[0015] The average value of the pressure distribution skewness of all maximum value points on the pressure signal is used as a reference feature, and the ratio of the reference feature to the absolute value of the reference feature is used as an identifier of the deflection direction.

[0016] Furthermore, the method for obtaining the defect probability includes:

[0017] The surface undulation degree and the overall skewness are multiplied and then normalized to obtain an initial defect probability in one direction; the average of the initial defect probabilities in two directions is taken as the defect probability.

[0018] Furthermore, the setting of the adjustment direction includes:

[0019] If the identifier is 1, the adjustment direction should be a direction of reducing the overlap; if the identifier is -1, the adjustment direction should be a direction of increasing the overlap.

[0020] Furthermore, the method for obtaining the adjustment amount includes:

[0021] The defect probability is multiplied by a preset maximum adjustment amount to obtain the adjustment amount.

[0022] The present invention also proposes a method for automatically punching and cutting lithium battery pole pieces, wherein the method utilizes the automatic punching and cutting device for lithium battery pole pieces to automatically punch and cut lithium battery pole pieces.

[0023] The present invention has the following beneficial effects:

[0024] The present invention further provides a fixed roller and a movable roller after the extruded disc cutter body, that is, after the pole piece is punched through the disc cutter body, two pole pieces are formed, which will pass through the fixed roller and the movable roller. The movable roller is connected to the spring so that it can move due to the pressure of the pole piece, and then the pressure sensor at the other end of the spring is used to collect the pressure signal of the pole piece in this direction. If there is a wavy edge on the pole piece, the shape of the wavy edge will cause the movement of the movable roller to produce corresponding undulations, so that the collected pressure signal can accurately characterize the morphological characteristics of the current pole piece. Then, the data processing module is used to determine the surface undulation degree and the pressure distribution skewness according to the data distribution on the pressure signal, and then the defect probability is determined and the overlap amount of the tool is accurately adjusted according to the defect probability and the deflection direction. By detecting the morphology of the pole piece and adaptively adjusting the overlap amount, the quality of the pole piece in the subsequent punching process can be guaranteed, and a large number of low-quality pole pieces can be avoided, thereby ensuring the quality of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the structure of an automatic punching and cutting device for lithium battery pole pieces provided by one embodiment of the present invention;

[0027] Figure 2 A flow chart of a data processing method of a data processing module provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a wavy edge generated when a disc cutter body punches a pole piece provided by an embodiment of the present invention.

[0029] In the figure: 1, upper cutter disc; 2, lower cutter disc; 3, battery pole piece; 401, first fixed roller; 402, second fixed roller; 501, first movable roller; 502, second movable roller; 601, first spring; 602, second spring; 701, first pressure sensor; 702, second pressure sensor. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation, structure, features and effects of a lithium battery pole piece automatic punching device and method proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0032] The embodiment of the present invention makes improvements on the extruded disc cutter body, wherein the disc cutter body is mainly composed of two upper and lower cutter discs. When cutting the pole piece, when the pole piece sheet first contacts the cutter disc, it will produce elastic deformation due to the pressure from the upper and lower cutter surfaces, and the plate will bend due to the existence of torque, and stress mainly composed of shear stress will be generated inside the material near the tool gap. As the cutter disc rotates, when the internal stress state meets the plastic condition, plastic deformation will occur. As the shearing process continues, the shear force on the plate becomes larger and larger, and it enters the shear yield state. The shear deformation zone begins to produce macroscopic slip deformation, and the upper and lower circular cutter shear blades begin to cut into the material. At this time, the material near the edge produces plastic deformation, shear plastic slip is formed, and the cross section is bright. As the cutter disc continues to rotate, the degree of plastic deformation of the material intensifies, the material will undergo work hardening, and its stress state will also change, resulting in micro cracks inside the material. As the deformation continues, these micro cracks merge into main cracks, transform into crack expansion and separate, and a tearing zone is formed on the cross section, thereby shearing the pole piece sheet into two pole pieces. It should be noted that the punching of the pole piece by a disc cutter is a technical means well known to those skilled in the art, and only the principle is briefly described here without repeating the details.

[0033] See also Figure 1 , which shows a schematic diagram of the structure of an automatic punching device for lithium battery pole pieces provided by an embodiment of the present invention. In the embodiment of the present invention, based on the disc cutter body, fixed rollers and movable rollers are respectively installed in two directions to loosen the pole pieces after cutting by two cutter discs. Figure 1 In the figure, the upper blade 1 and the lower blade 2 cut the battery electrode 3, and two electrode sheets are formed after cutting and transported in their respective transport directions. The electrode sheet in one transport direction passes through the first fixed roller 401 and the first movable roller 501; the electrode sheet in the other transport direction passes through the second fixed roller 402 and the second movable roller 502. Furthermore, the movable roller is subjected to the pressure of the electrode sheet, causing it to move on the spring, one end of the spring is connected to the movable roller, and the other end is connected to the fixed pressure sensor. Figure 1 As shown, the first movable roller 501 is connected to the first spring 601, and the other end of the first spring 601 is connected to the first pressure sensor 701; similarly, the second movable roller 502 is connected to the second spring 602, and the other end of the second spring 602 is connected to the second pressure sensor 702. The pressure sensor is used to collect the pressure signal fed back by the movable roller when the pole piece is transported between the fixed roller and the movable roller in real time. That is, for each real-time moment, the first pressure sensor 701 can feed back a pressure signal, and the second pressure sensor 702 can also feed back a pressure signal.

[0034] In one embodiment of the present invention, a set of pressure signals is fed back at each real-time moment, and a set of pressure signals includes two pressure signals, which respectively represent the two pole pieces after slitting. The sampling frequency of the embodiment of the present invention is set to 50Hz, and for each real-time moment, the pressure data collected within 5 seconds before the real-time moment constitute the pressure signal of the real-time moment.

[0035] During the transmission process after the pole piece is cut, the pole piece will pass through the gap between the fixed roller and the movable roller, and the shape of the pole piece will cause the movable roller to move up and down on the spring. If the pole piece is flat, the movable roller will not produce obvious movement, and the pressure signal fed back by the pressure sensor will be relatively smooth and will not produce obvious pressure changes; if the pole piece has obvious wavy edges, the movable roller will move up and down due to the influence of the wavy edges, and then cause the pressure sensor to feed back an up and down pressure signal. Therefore, the shape of the pole piece can be characterized by analyzing the distribution of signal points on the pressure signal. The automatic pole piece punching equipment provided in an embodiment of the present invention also includes a data processing module, which is used to receive and analyze the pressure signal, determine the defect probability of the pole piece producing a wavy edge, and adjust the overlap of the two cutter discs in the disc cutter body according to the defect probability. Please refer to Figure 2 , which shows a flow chart of a data processing method of a data processing module provided by an embodiment of the present invention, the method comprising:

[0036] Step S1: Determine the surface undulation degree of the pole piece according to the fluctuation degree of the pressure signal and the pressure value.

[0037] The pressure value represented by the pressure signal can directly represent the morphological characteristics of the current electrode. If the pressure value on the pressure signal is small, it means that the moving roller has not produced obvious displacement and the flatness of the electrode is high. Similarly, if the pressure fluctuation on the pressure signal is weak, it means that the moving roller is relatively stable and the flatness of the electrode is high. Therefore, the surface undulation of the electrode can be determined by the fluctuation degree of the pressure signal and the pressure value, that is, the greater the fluctuation degree and the greater the pressure value, the greater the surface undulation of the electrode.

[0038] Preferably, in one embodiment of the present invention, in order to further reflect the fluctuation degree of the pressure signal to be analyzed and the abnormal degree of the pressure value, the two pressure characteristics are compared with the standard pressure characteristics to further highlight the surface fluctuation degree of the electrode at the real time, specifically including:

[0039] The average pressure value of the pressure signal is taken as the overall pressure value, and the variance is taken as the pressure fluctuation feature; the ratio of the overall pressure value to the standard pressure value is taken as the first contrast feature, and the ratio of the pressure fluctuation feature to the standard pressure fluctuation feature is taken as the second contrast feature; the surface fluctuation degree is obtained according to the first contrast feature and the second contrast feature. That is, the larger the first contrast feature and the second contrast feature, the greater the pressure feature on the real-time pressure signal is relative to the standard pressure feature, and the greater the surface fluctuation degree.

[0040] In one embodiment of the present invention, in order to further quantify the surface undulation degree, it is considered that if the overall pressure value is close to the standard pressure value, the first contrast feature is close to 1; similarly, the closer the pressure fluctuation feature is to the standard pressure fluctuation feature, the closer the second contrast feature is to 1. Therefore, the surface undulation degree is quantified according to a preset surface undulation degree formula, and the surface undulation degree formula includes:

[0041] ;in is the surface undulation degree of the pole piece at the rth moment; sigmoid ( ) is a common activation function used for normalization processing; is the overall pressure value; is the standard pressure value; is the pressure fluctuation characteristic; It is the standard pressure fluctuation characteristic.

[0042] In the surface undulation degree formula, if the overall pressure value is close to the standard pressure value, and the pressure fluctuation feature is closer to the standard pressure fluctuation feature, the product of the first contrast feature and the second contrast feature is closer to 1, and the result is closer to 0 after further subtraction from the positive integer 1; if the overall pressure value is greater than the standard pressure value, and the pressure fluctuation feature is greater than the standard pressure fluctuation feature, the product of the first contrast feature and the second contrast feature is greater than 1, and the subtraction result is greater than 0. Therefore, the first contrast feature and the second contrast feature are merged by multiplication, and subtraction from the positive integer 1 can obviously quantify the current data results, and further normalization with the sigmoid function can obtain the surface undulation degree with a value range between 0 and 1.

[0043] It should be noted that, because two pole pieces are generated when the pole piece is sheared by the disc cutter, each pole piece corresponds to a pressure signal at the real time, and therefore each pole piece corresponds to a surface undulation degree.

[0044] Step S2: Determine the local pressure distribution skewness of each maximum point according to the coordinate distribution between the maximum point and the adjacent minimum point on the pressure signal; obtain the overall skewness and deflection direction of the pole piece according to the pressure distribution skewness of each maximum point.

[0045] When the disc cutter cuts the pole piece, if the overlap of the blade is too large, a large shear force will be generated, which will cause the battery pole piece to have a wavy edge. Due to the large shear force, the wavy edge has a certain stacking effect, which causes the overall wavy edge to be biased in the direction of movement. If the overlap of the blade is too small, the tool will not be able to completely bite the material, the pole piece will not be sheared thoroughly, and the pole piece material may have uneven stress distribution near the shearing point, thus forming a wavy edge on the cut pole piece. At this time, the wavy edge will have strong irregularity. Due to the small overlap and discontinuous bite, the overall wavy edge will be biased in the opposite direction of the moving direction. Please refer to Figure 3 , which shows a schematic diagram of a wavy edge generated when a disc cutter body provided by an embodiment of the present invention punches a pole piece, Figure 3 In the embodiment of the present invention, the wave edge generated by the pole piece in the moving direction obviously has a certain skewness. Therefore, the embodiment of the present invention continues to analyze the skewness characteristics on the pressure signal to further determine the defect of the pole piece at the real time.

[0046] The embodiment of the present invention first performs a local analysis on the pressure signal, selects the maximum point as the main analysis object, and determines the skewness of the local pressure distribution of each maximum point according to the coordinate distribution between the maximum point and the adjacent minimum point on the pressure signal. That is, the maximum point and the adjacent minimum point constitute a local range, and the skewness of the pressure distribution can be determined according to the coordinate distribution within the local range. For example, if the maximum point is closer to the minimum point on the left and the pressure difference is greater, it means that the fluctuation within the local range is more biased to the left.

[0047] Preferably, in one embodiment of the present invention, the method for obtaining the pressure distribution skewness includes:

[0048] For each maximum point on the pressure signal, the minimum point closest to the left in time sequence is taken as the first minimum point, and the minimum point closest to the right is taken as the second minimum point.

[0049] A first timing difference and a first pressure difference between the maximum point and the first minimum point are obtained; a second timing difference and a second pressure difference between the maximum point and the second minimum point are obtained. In the embodiment of the present invention, the absolute value of the difference between the horizontal coordinates of the two points is directly used as the timing difference, and the absolute value of the difference between the vertical coordinates is used as the pressure difference.

[0050] The ratio of the first pressure difference to the first time series difference is taken as the first change feature, and the ratio of the second pressure difference to the second time series difference is taken as the second change feature. The larger the ratio of the pressure difference to the time series difference, the stronger the change in the pressure data is in a shorter period of time, that is, the larger the first change feature is, the more drastic the change in the data on the left side of the maximum point is; the larger the second change feature is, the more drastic the change in the data on the right side of the maximum point is. Therefore, the difference between the first change feature and the second change feature is taken as the skewness feature of the pressure distribution of the maximum point. The larger the skewness feature of the pressure distribution is, the larger the first change feature is relative to the second change feature at this time, and the pressure data change is more biased to the left side of the maximum point. It can be further known that the larger the absolute value of the skewness feature of the pressure distribution is, the more obvious the skewness distribution is in the local range of the pressure signal at this time, and the greater the degree of wave edge generated by the pole piece at the real time.

[0051] Because the pressure distribution skewness represents the skewness in the local range of the pressure signal, the larger the skewness in the local range, the more likely the pole piece is to have a wavy edge due to improper tool overlap. Therefore, the overall skewness and deflection direction of the pole piece can be obtained based on the pressure distribution skewness of each maximum point. The larger the overall skewness, the greater the probability of a wavy edge defect. The determination of the deflection direction can determine the adjustment direction of the overlap in the subsequent analysis process.

[0052] Preferably, in one embodiment of the present invention, the overall skewness is the average of the absolute values ​​of the pressure distribution skewness of all maximum value points on the pressure signal.

[0053] Further, the average value of the pressure distribution skewness of all maximum points on the pressure signal is used as a reference feature, and the ratio of the reference feature to the absolute value of the reference feature is used as an identifier of the deflection direction. It should be noted that the purpose of performing the ratio operation on the reference feature and the absolute value of the reference feature in this step is to extract the sign of the reference feature, that is, the obtained identifier has only two states of 1 and -1. Because the conveying direction of the pole piece is opposite to the timing direction of the pressure signal, that is, the latest pole piece position in the conveying direction corresponds to the last pressure data on the pressure signal. Therefore, if the reference feature is a positive value, the identifier is 1, indicating that the overall data change direction on the pressure signal is biased towards the opposite direction in the timing, which means that the wave deflection of the pole piece at this time is more biased towards the movement direction of the lithium battery pole piece, indicating that the overlap of the cutter disc is large at this time and needs to be reduced. Similarly, if the reference feature is a negative value, the identifier is -1, indicating that the overlap of the cutter disc is small at this time and needs to be increased. Therefore, if the identifier is 1, the adjustment direction should be the direction of reducing the overlap; if the identifier is -1, the adjustment direction should be the direction of increasing the overlap.

[0054] Step S3: Determine the defect probability based on the surface undulation degree and the overall skewness.

[0055] As described in the above steps, the greater the surface undulation and the greater the overall skewness, the greater the probability that the pole piece will have a wavy edge defect. Therefore, the defect probability can be determined based on the surface undulation and the overall skewness.

[0056] Preferably, in the embodiment of the present invention, because there are two pole pieces at this time, each pole piece corresponds to a surface undulation degree and an overall skewness, so for one pole piece, the surface undulation degree and the overall skewness are multiplied and then normalized to obtain the initial defect probability in one direction. The mean of the initial defect probabilities in the two directions is taken as the defect probability. In the embodiment of the present invention, normalization can also be implemented using a sigmoid function, which will not be elaborated or limited here.

[0057] Step S4: determining the adjustment direction of the overlap amount according to the deflection direction, determining the adjustment amount of the overlap amount according to the defect probability, and sending an overlap amount control signal to the disc cutter body.

[0058] Because the deflection direction can represent the tool overlap state when punching the pole piece in real time, the adjustment direction of the overlap can be determined according to the deflection direction. Further considering that the greater the defect probability, the easier it is for the pole piece to produce a wavy edge or the greater the degree of the wavy edge produced, the adjustment amount of the overlap can be determined according to the defect probability, and an overlap control signal is sent to the disc cutter body, and the overlap control signal includes the adjustment amount and the adjustment direction.

[0059] Preferably, in the embodiment of the present invention, considering that the defect probability is data between 0 and 1, the defect probability is directly multiplied by the preset maximum adjustment amount to obtain the adjustment amount. It should be noted that the preset maximum adjustment amount can be set according to the specifications of the disc cutter body and is not limited here.

[0060] In summary, the embodiment of the present invention is provided with a fixed roller and a movable roller after the extruded disc cutter body, that is, after the pole piece is punched through the disc cutter body, two pole pieces are formed, which will pass through the fixed roller and the movable roller. The movable roller is connected to the spring so that it can move due to the pressure of the pole piece, and then the pressure sensor at the other end of the spring is used to collect the pressure signal of the pole piece in this direction. If there is a wavy edge on the pole piece, the shape of the wavy edge will cause the movement of the movable roller to produce corresponding undulations, so that the collected pressure signal can accurately characterize the morphological characteristics of the current pole piece. Then, the data processing module is used to determine the surface undulation degree and the pressure distribution skewness according to the data distribution on the pressure signal, and then the defect probability is determined and the overlap amount of the tool is accurately adjusted according to the defect probability and the deflection direction. By detecting the morphology of the pole piece and adaptively adjusting the overlap amount, the quality of the pole piece in the subsequent punching process can be guaranteed, and a large number of low-quality pole pieces can be avoided, thereby ensuring the quality of the finished product.

[0061] Based on the above-mentioned automatic punching and cutting device for lithium battery pole pieces, the present invention also proposes a method for automatic punching and cutting of lithium battery pole pieces, which utilizes an automatic punching and cutting device for lithium battery pole pieces to automatically punch and cut lithium battery pole pieces. The process has been explained through the content of the above-mentioned automatic punching and cutting device for lithium battery pole pieces, and will not be repeated here.

[0062] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0063] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A lithium battery pole piece automatic punching device, comprising a disc cutter body, wherein the disc cutter body comprises two cutter discs, characterized in that: The device is respectively equipped with a fixed roller and a movable roller in two directions of conveying the electrode piece after cutting by two cutter discs; the movable roller is moved under the action of a spring under the pressure of the electrode piece, one end of the spring is connected to the movable roller, and the other end is connected to a fixed pressure sensor; the pressure sensor is used to collect in real time the pressure signal fed back by the movable roller when the electrode piece is conveyed between the fixed roller and the movable roller; the device also includes a data processing module, which receives and analyzes the pressure signal, determines the defect probability of the electrode piece generating a wavy edge, and adjusts the overlap amount of the two cutter discs in the disc cutter body according to the defect probability; The data processing method of the data processing module includes: In real time, the surface undulation degree of the electrode piece is determined according to the fluctuation degree of the pressure signal and the pressure value; According to the coordinate distribution between the maximum point and the adjacent minimum point on the pressure signal, the local pressure distribution skewness of each maximum point is determined; according to the pressure distribution skewness of each maximum point, the overall skewness and deflection direction of the pole piece are obtained; according to the surface undulation degree and the overall skewness, the defect probability is determined; according to the deflection direction, the adjustment direction of the overlap amount is determined, according to the defect probability, the adjustment amount of the overlap amount is determined, and an overlap amount control signal is sent to the disc cutter body.

2. The automatic punching equipment for lithium battery pole pieces according to claim 1, characterized in that: The method for obtaining the surface undulation degree comprises: The average pressure value of the pressure signal is used as the overall pressure value, and the variance is used as the pressure fluctuation feature; the ratio of the overall pressure value to the standard pressure value is used as the first comparison feature, and the ratio of the pressure fluctuation feature to the standard pressure fluctuation feature is used as the second comparison feature; the surface undulation degree is obtained according to the first comparison feature and the second comparison feature; The method for obtaining the standard pressure value and the standard pressure fluctuation characteristic includes: The moment when the electrode begins to be punched is taken as the starting moment, and all pressure signals between the starting moment and the real time moment are spliced ​​to obtain an overall pressure signal; the average pressure value of the overall pressure signal is taken as the standard pressure value, and the variance is taken as the standard pressure fluctuation characteristic.

3. The automatic punching and cutting device for lithium battery pole pieces according to claim 1, characterized in that: The method for obtaining the pressure distribution skewness includes: For each maximum point on the pressure signal, the minimum point closest to the left in time sequence is taken as the first minimum point, and the minimum point closest to the right in time sequence is taken as the second minimum point; the first time sequence difference and the first pressure difference between the maximum point and the first minimum point are obtained; the second time sequence difference and the second pressure difference between the maximum point and the second minimum point are obtained; the ratio of the first pressure difference to the first time sequence difference is taken as the first change feature, and the ratio of the second pressure difference to the second time sequence difference is taken as the second change feature; the difference between the first change feature and the second change feature is taken as the pressure distribution skewness feature of the maximum point.

4. The automatic punching and cutting device for lithium battery pole pieces according to claim 3, characterized in that: The overall skewness is the average of the absolute values ​​of the pressure distribution skewness of all maximum points on the pressure signal.

5. The automatic punching and cutting device for lithium battery pole pieces according to claim 4, characterized in that: The method for obtaining the deflection direction includes: The average value of the pressure distribution skewness of all maximum value points on the pressure signal is used as a reference feature, and the ratio of the reference feature to the absolute value of the reference feature is used as an identifier of the deflection direction.

6. The automatic punching and cutting device for lithium battery pole pieces according to claim 1, characterized in that: The method for obtaining the defect probability includes: The surface undulation degree and the overall skewness are multiplied and then normalized to obtain an initial defect probability in one direction; the average of the initial defect probabilities in two directions is taken as the defect probability.

7. The automatic punching and cutting device for lithium battery pole pieces according to claim 5, characterized in that: The setting of the adjustment direction includes: If the identifier is 1, the adjustment direction should be a direction of reducing the overlap; if the identifier is -1, the adjustment direction should be a direction of increasing the overlap.

8. The automatic punching and cutting device for lithium battery pole pieces according to claim 1, characterized in that: The method for obtaining the adjustment amount includes: The defect probability is multiplied by a preset maximum adjustment amount to obtain the adjustment amount.

9. A method for automatically punching lithium battery pole pieces, characterized in that: The method utilizes the lithium battery pole piece automatic punching equipment as described in claim 1 to automatically punch the lithium battery pole piece.

Images