Electrode sheet cutting device and cutting method

Abstract

The present invention relates to an electrode sheet cutting device and a cutting method, and more particularly, to a vision system that recognizes the shape of an electrode tab, grasps the cutting position, and determines the cutting position of the electrode sheet, thereby improving the accuracy of cutting the electrode sheet.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0179723 dated December 15, 2021, and all contents disclosed in the documents of the relevant Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an electrode sheet cutting device and a cutting method for improving the accuracy of the cutting position when cutting an electrode sheet. [Background technology]

[0003] Generally, a secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in advanced electronic devices such as automobiles, phones, laptops, and camcorders.

[0004] The secondary batteries are classified into can-type secondary batteries in which an electrode assembly is housed in a metal can and pouch-type secondary batteries in which an electrode assembly is housed in a pouch. The pouch-type secondary battery includes an electrode assembly, an electrolyte, and a pouch that contains the electrode assembly and the electrolyte. The electrode assembly has a structure in which a plurality of electrodes and a plurality of separators are alternately stacked.

[0005] The lamination process, one of the unit processes used to assemble automotive batteries, involves unwinding rolls of electrodes, cutting them individually at target locations, and then mating and sealing them with separators to produce semi-finished products in the form of monocells or bicells. A monocell or bicell refers to a semi-finished product in which a laminate consisting of electrodes of opposite polarity and a separator between them is cut to an appropriate size.

[0006] In the lamination process, the unwound electrode is cut at the target position by a tab sensor that detects the linear section of the tab before cutting and calculates the distance to be cut.

[0007] In this case, the tab detection sensor must clearly recognize the straight section of the tab in order to accurately calculate the distance to be cut. If the electrode meanders, causing a change in the path line, or if the setting position of the tab detection sensor is misaligned, the tab detection sensor will not be able to accurately recognize the straight section of the tab, which may result in a decrease in the accuracy of the cutting position and lead to the production of defective electrodes. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent No. 1509208 Summary of the Invention [Problem to be solved by the invention]

[0009] As a result of extensive research to solve the above problems, the inventors have found that the accuracy of determining the cutting position of the electrode sheet can be improved by using a vision that recognizes the overall shape of tabs formed at regular intervals on the electrode sheet.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electrode sheet cutting device that improves the accuracy of cutting an electrode sheet.

[0011] Another object of the present invention is to provide an electrode sheet cutting method that improves the accuracy of cutting the electrode sheet. [Means for solving the problem]

[0012] Therefore, the present invention provides a method for manufacturing an electrode sheet having a plurality of electrode tabs formed at regular intervals on one side thereof, the method comprising: a conveying unit for conveying the electrode sheet from a measurement point to a cutting point; a sensing unit provided at the measurement point for sensing the shape of an electrode tab formed on the electrode sheet passing through the measurement point and generating an electrode tab sensing signal; a control unit that receives the electrode tab detection signal generated by the detection unit and determines a cutting portion of the electrode sheet; The electrode sheet cutting device includes a cutting unit that cuts the cutting portion of the electrode sheet determined by the control unit.

[0013] The sensing unit may include a vision system that senses the shape of an electrode tab formed on the electrode sheet passing the measurement point and generates an electrode tab sensing signal.

[0014] The vision system may include a vision camera that can recognize the overall shape of the electrode tab.

[0015] The control unit may determine positions of the electrode tabs and cutting portions between adjacent electrode tabs using the transmitted electrode tab sensing signal.

[0016] The present invention also provides a method for manufacturing a cutting device, comprising the steps of: (S1) transporting an electrode sheet having a plurality of electrode tabs formed at regular intervals on one side thereof from a measurement point to a cutting point; (S2) sensing the shape of an electrode tab formed on the electrode sheet passing the measurement point and generating an electrode tab sensing signal; (S3) determining a cutting position on the electrode sheet using the electrode tab sensing signal; and (S4) cutting the electrode sheet according to the determined cutting position. [Effects of the Invention]

[0017] According to the electrode sheet cutting device of the present invention, the overall shape of the tabs formed on the electrode sheet being transported in one direction is sensed using a vision, and the cutting position of the electrode sheet is determined based on the sensed tab shape, thereby improving the accuracy of cutting the electrode sheet. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of an electrode sheet cutting device according to an embodiment of the present invention; [Figure 2a] 10 is a schematic diagram illustrating the shape of an electrode tab sensed by a vision system according to one embodiment of the present invention. [Figure 2b] 10 is a schematic diagram illustrating the shape of an electrode tab sensed by a vision system according to one embodiment of the present invention. [Figure 3] 10 is a schematic diagram illustrating a process of determining a cutting location using the shape of an electrode tab sensed by a vision system and then cutting an electrode sheet according to an embodiment of the present invention. FIG. [Figure 4a] 10 is a schematic diagram showing the shape of an electrode tab sensed by a vision system according to a comparative example of the present invention. FIG. [Figure 4b] 10 is a schematic diagram showing the shape of an electrode tab sensed by a vision system according to a comparative example of the present invention. FIG. [Figure 5] 10 is a schematic diagram showing a process in which an electrode sheet is cut after a cutting location is determined using the shape of an electrode tab sensed by a vision system according to a comparative example of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following description will be given with reference to the drawings according to the embodiments of the present invention, but this is for easier understanding of the present invention and does not limit the scope of the present invention.

[0020] Electrode sheet cutting device The present invention relates to an electrode sheet cutting device that can improve the accuracy of electrode sheet cutting by detecting the shape of electrode tabs formed at regular intervals on the side of an electrode sheet and determining the cutting position of the electrode sheet using the detected shape of the electrode tabs.

[0021] FIG. 1 is a schematic diagram of an electrode sheet cutting device according to an embodiment of the present invention.

[0022] Referring to FIG. 1, the electrode sheet cutting device 1 includes a conveying unit 100 that conveys an electrode sheet 110 having a plurality of electrode tabs 120 formed at regular intervals on one side thereof through a measuring point A to a cutting point B; a sensing unit (200) provided at the measurement point (A) for sensing the shape of the electrode tab (120) formed on the electrode sheet (110) passing through the measurement point (A) and generating an electrode tab (120) sensing signal; a control unit (300) that receives the electrode tab (120) detection signal generated by the detection unit (200) and determines the cutting position of the electrode sheet (110); The cutting unit 400 cuts the cutting portion of the electrode sheet 110 determined by the control unit 300 .

[0023] Transfer section In the present invention, the transfer unit 100 transfers the electrode sheet 110 having the electrode tabs 120 formed thereon through a measurement point A to a cutting point B. The transfer unit 100 includes a conveyor belt that transfers the electrode sheet 110 so that the electrode tabs 120 formed at regular intervals on the side of the electrode sheet 110 are transferred in order through the measurement point A to the cutting point B, and the conveyor belt is made up of a pair of belts that support and transfer the electrode sheet 110 at the same time.

[0024] Here, the conveyor belt generally refers to a belt-shaped device that continuously moves and / or transports objects, and is not particularly limited as long as it is a conveyor belt commonly used in the industry. For example, a conveyor belt applicable to the transfer unit 100 may include a belt portion that rotates while being wound around a first roller and a second roller disposed at both ends of the length. Here, the length direction may refer to one direction in which the electrode sheet moves.

[0025] Sensing part In the present invention, the sensing unit 200 is provided at the measurement point A and senses the shape of the electrode tabs 120 formed on the electrode sheet 110 passing through the measurement point A to generate an electrode tab 120 sensing signal. In this case, the sensing unit 200 being provided at the measurement point A means that the sensing unit 200 is installed at a position where the shape of the electrode tabs 120 formed on the electrode sheet 110 passing through the measurement point A can be confirmed.

[0026] The sensing unit 200 may include a vision system 210 that detects the position of the electrode tab 120 by checking the shape of the electrode tab 120 passing through the measurement point A, and then generates an electrode tab 120 sensing signal. At this time, the vision system 210 may check the overall shape of the electrode tab 120.

[0027] The vision system 210 includes a vision camera and can sense the shape of the electrode tabs 120 when the electrode sheet 100 is transported, thereby determining the position of the electrode tabs 120 and ultimately determining the cutting position of the electrode sheet 110.

[0028] At this time, the vision system 210 can sense and confirm the overall shape of the electrode tab 120, so even if the size or shape of the electrode tab 120 is somewhat irregular, it can recognize it as an electrode tab 120 based on its overall shape.

[0029] The cutting position may be determined to be a midpoint between adjacent electrode tabs 120 .

[0030] Figures 2a and 2b are schematic diagrams showing the shape of an electrode tab sensed by a vision system according to one embodiment of the present invention, and Figures 2a and 2b show the case where the lengths a and b of the straight section SA of the electrode tab 120 are different (a>b).

[0031] 2a and 2b, the area VA sensed by the vision system includes the overall shape of the electrode tab 120. Therefore, the vision system can sense the electrode tab 120 even if the design of the electrode tab 120 varies slightly. For example, the length a of the straight section SA of the electrode tab 120 in FIG. 2a is longer than the length b of the straight section SA of the electrode tab 120 in FIG. 2b. However, because the vision system senses the electrode tab 120 based on its overall shape, it can properly sense the electrode tab 120 and accurately determine the cutting position in both cases.

[0032] Control Unit In the present invention, the control unit 300 receives the electrode tab detection signal generated by the detection unit 200 and calculates and determines the accurate cutting position on the electrode sheet 110 .

[0033] The cutting position may be determined to be a midpoint between adjacent electrode tabs 120 .

[0034] For example, the center value of the adjacent electrode tabs 120 can be calculated using the electrode tab 120 sensing signal transmitted from the sensing unit 200 to determine the cutting position.

[0035] The control unit can use a programmable logic controller (PLC) or a universal machine and automation controller (UMAC) to determine the cutting position.

[0036] Cutting section In the present invention, the cutting unit 400 is provided at the cutting point B and cuts the electrode sheet 110 passing through the cutting point B according to the cutting position determined by the control unit 400, thereby obtaining a unit electrode 2.

[0037] That is, when the sensing unit 200 senses the electrode tab 120 passing through the measurement point A and determines the cutting position, the cutting unit 400 cuts the electrode sheet 110 passing through the cutting point B at the determined cutting position.

[0038] The electrode sheet cutting device according to one embodiment of the present invention having such a configuration has a feature of detecting the position based on the shape of the electrode tabs formed on the electrode sheet and cutting the electrode sheet. This feature allows the time point for cutting the electrode sheet to be detected accurately, thereby enabling the electrode sheet to be cut accurately, resulting in unit electrodes of uniform quality.

[0039] Electrode sheet cutting method The present invention also relates to an electrode sheet cutting method, the electrode sheet cutting method including the steps of (S1) continuously transporting an electrode sheet having a plurality of electrode tabs formed at regular intervals on one side thereof through a measurement point to a cutting point using a transport unit, (S2) sensing the shapes of the electrode tabs formed on the electrode sheet passing the measurement point to generate an electrode tab sensing signal, (S3) determining a cutting position on the electrode sheet using the electrode tab sensing signal, and (S4) cutting the electrode sheet according to the determined cutting position. The electrode sheet cutting method can be performed using the electrode sheet cutting device described above.

[0040] The steps (S1), (S2), (S3) and (S4) may be performed in a conveying unit, a sensing unit, a control unit and a cutting unit of the electrode sheet cutting device, respectively.

[0041] FIG. 3 is a schematic diagram illustrating a process of determining a cutting location using the shape of an electrode tab sensed by a vision system and then cutting an electrode sheet according to an embodiment of the present invention.

[0042] Referring to FIG. 3, the position of the electrode tabs 120 can be determined using the shape of the electrode tabs 120 identified in the area VA sensed by the vision system, and a cutting point B can be determined at the midpoint between adjacent electrode tabs 120, and a unit electrode 2 can be manufactured by cutting.

[0043] 4a and 4b are schematic diagrams showing the shape of an electrode tab sensed by a sensor according to a comparative example of the present invention. The sensor recognizes the electrode tab by sensing the linear section of the electrode tab. 4a and 4b show the case where the lengths a and b of the linear section SA of the electrode tab 120 are different (a>b).

[0044] FIG. 5 is a schematic diagram showing a process of determining a cutting location using the shape of an electrode tab sensed by a vision system and then cutting an electrode sheet according to a comparative example of the present invention.

[0045] Referring to Figures 4a and 4b, since the sensor detects the straight section of the electrode tab, if the length of the straight section changes, the sensor may not be able to detect the electrode tab. If the cutting point is determined incorrectly, cutting may occur at an abnormal position, as shown in Figure 5, resulting in a defect.

[0046] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content.

[0047] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is of course possible for a person skilled in the art to which the present invention pertains to make various modifications and variations within the technical spirit of the present invention and the equivalent scope of the claims set forth below. [Explanation of symbols]

[0048] 1: Electrode sheet cutting device 2: Unit electrode 100:Transfer section 110: Electrode sheet 120: Electrode tab 200: Sensing part 210: Vision System 300: Control unit 400: Cutting section A: Measurement point B: Cutting point VA: Area sensed by the vision system SA: Straight section of electrode tab a, b: Length of the straight section of the electrode tab

Claims

1. a transfer unit for transferring an electrode sheet having a plurality of electrode tabs formed at regular intervals on one side thereof from a measurement point to a cutting point; a sensing unit provided at the measurement point for sensing the overall shape of the electrode tab formed on the electrode sheet passing through the measurement point and generating an electrode tab sensing signal; a control unit that receives the electrode tab detection signal generated by the detection unit and determines a cutting portion of the electrode sheet; and an electrode sheet cutting device including a cutting unit that cuts the cutting portion of the electrode sheet determined by the control unit;

2. 2. The electrode sheet cutting device of claim 1, wherein the sensing unit includes a vision system that senses the overall shape of the electrode tab formed on the electrode sheet passing through the measurement point and generates an electrode tab sensing signal.

3. The electrode sheet cutting device according to claim 2 , wherein the vision system includes a vision camera capable of recognizing the overall shape of the electrode tab.

4. 2. The electrode sheet cutting device of claim 1, wherein the control unit determines the positions of the electrode tabs and cutting areas between adjacent electrode tabs using the transmitted electrode tab sensing signal.

5. (S1) transferring an electrode sheet having a plurality of electrode tabs formed at regular intervals on one side thereof from a measurement point to a cutting point; (S2) sensing the overall shape of the electrode tab formed on the electrode sheet passing through the measurement point and generating an electrode tab sensing signal; (S3) determining a cutting position on the electrode sheet using the electrode tab sensing signal; and (S4) cutting the electrode sheet according to the determined cutting position.

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