Battery cell weld inspection device and battery cell weld inspection method using the same

Abstract

The present invention relates to a battery cell welded part inspection device and a welded part inspection method using the same, the device including a plate on which a battery cell cassette in which a plurality of battery cells are arranged is mounted, an Orthogonal robot that moves on an upper part of the battery cell cassette fixed to the plate, a laser pointer connected to the Orthogonal robot for indicating a defective battery cell among the plurality of battery cells, and an alignment unit that aligns a position of the battery cell cassette so that the battery cell cassette is positioned within an operating area of ​​the Orthogonal robot, and the device can prevent defective battery cells from being omitted from inspection at the final inspection stage of checking for weld defects.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0119053, filed September 21, 2022, and all contents disclosed in the Korean Patent Application are incorporated herein by reference.

[0002] The present invention relates to a battery cell weld inspection device and a battery cell weld inspection method using the same, and more particularly to a battery cell weld inspection device and a battery cell weld inspection method using the same that are capable of manually inspecting battery cells that are identified as having poor welds through voltage, current, and temperature measurements, and then performing a final inspection on all of the defective battery cells without omission. [Background technology]

[0003] Lithium secondary batteries, which are charged and discharged by the movement of lithium ions, have the advantages of high energy density and high charging voltage, and are therefore used not only in the field of small battery cells used in mobile devices and small electronic products, but also in the field of medium- to large-sized battery packs used as energy sources for electric vehicles and power storage systems that require high output and high voltage.

[0004] In order to manufacture such a medium- to large-sized battery pack, a process of electrically connecting a plurality of cylindrical battery cells is required. For example, a method of connecting metal plates to positive and negative terminals of the cylindrical battery cells by wire welding can be used.

[0005] If the connection between the wires connected to the positive and negative terminals of the cylindrical battery cell is weak, the wires may easily break due to impact. Conversely, if the connection is strong, the gasket may be damaged, causing electrolyte leakage or electrical disconnection.

[0006] Such problems can degrade the performance of the cylindrical battery cell or pose a safety hazard.

[0007] Therefore, it is necessary to thoroughly check the welding condition of the welded parts before assembling the battery pack to prevent the above problems from occurring.

[0008] However, as the number of battery cells that make up large battery packs such as those for electric vehicles has increased to 600 to 700, it is virtually impossible to manually inspect all battery cells for defects.

[0009] Therefore, recently, a method of checking for defective welds in battery cells is used, which involves measuring the voltage and current of the battery cell to check for resistance using a direct current internal resistance (DCIR) test.

[0010] Another method is to use a thermal imaging inspector to photograph the welds of the battery cells to check whether the temperature distribution is within the normal range.

[0011] In this regard, Patent Document 1 relates to a welding quality inspection system for inspecting welded parts of vehicle batteries, and discloses a welding quality inspection device that applies a current to a welded part and measures the voltage generated at the welded part.

[0012] Although Patent Document 1 provides a method for easily inspecting the welding quality of welded portions of batteries of various sizes, it does not provide a method for indicating which battery cells are defective.

[0013] In this way, after identifying battery cells with poor welds by measuring voltage and current or photographing the temperature of the welds, the worker can manually pull the welding wire of the battery cells with poor welds individually to check whether the welds are good or bad, thereby making it possible to determine whether the battery cells are passable or not.

[0014] However, due to worker error, defective battery cells may not be identified at the final stage and may end up being assembled into a battery pack. Therefore, it is necessary to thoroughly check all welds classified as defective battery cells to prevent the distribution of defective battery cells. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Korean Patent No. 10-1887148 Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a battery cell weld inspection device and a battery cell weld inspection method using the same that can prevent battery cells with defective welds from being overlooked in inspection and prevent the distribution of defective battery cells. [Means for solving the problem]

[0017] To achieve this object, a battery cell weld inspection device according to the present invention may include: a plate on which a battery cell cassette having a plurality of battery cells arranged therein is mounted; a Cartesian robot that moves above the battery cell cassette fixed to the plate; a laser pointer that is coupled to the Cartesian robot and that indicates a defective battery cell among the plurality of battery cells; and an alignment unit that aligns the position of the battery cell cassette so that the battery cell cassette is positioned within an operating area of ​​the Cartesian robot.

[0018] The battery cell cassette may further include a control unit that receives information on the internal resistance of the battery cell cassette and the position of a welded portion of a defective battery cell derived from the measurement result of a thermal imager, and controls the Cartesian robot.

[0019] The laser pointer can irradiate a laser beam onto the welded portions of the positive and negative terminals of the defective battery cell.

[0020] The plate may include a lift for adjusting the height of the plate, and the lift may be located below the plate.

[0021] The battery cell cassette includes four corner portions formed by two side surfaces meeting, and the alignment portion can align the battery cell cassette by moving toward or away from the four corner portions.

[0022] The plate may include a coupling portion for fixing the position of the battery cell cassette.

[0023] The battery pack may further include a number display unit that displays the number of defective battery cells.

[0024] The battery pack may further include a manual inspector that allows an operator to manually inspect the welded portion of the defective battery cell indicated by the laser pointer.

[0025] The manual tester may include a push-pull jig that pulls a wire at a welded portion of the defective battery cell, and an alarm unit that displays an alarm when the force of the push-pull jig pulling the wire reaches a set magnitude.

[0026] The number displayed on the number display unit may be decreased each time the worker checks the defective battery cell weld indicated by the laser pointer.

[0027] The battery cell weld inspection method using the battery cell weld inspection device includes the steps of: placing a battery cell cassette, in which a plurality of battery cells are mounted, on a plate; aligning the position of the battery cell cassette using an alignment unit; transmitting position information of a weld of a defective battery cell to a Cartesian robot; indicating the weld of the defective battery cell with a laser pointer according to movement of the Cartesian robot; and inspecting the weld of the defective battery cell indicated by the laser pointer by pulling it with a manual inspector, wherein the position information of the weld of the defective battery cell may be obtained from a result of measuring the internal resistance of the battery cell cassette and a result of measuring it with a thermal imaging inspector that have been previously performed.

[0028] When manual inspection of a specific defective battery cell among a plurality of defective battery cells is completed, the laser beam of the laser pointer indicates other defective battery cells, and when manual inspection of the other defective battery cells is completed, if there are further defective battery cells, the laser beam can be irradiated and manual inspection can be performed on the further defective battery cells.

[0029] The number of defective battery cells is displayed numerically on a number display unit, and each time the wire of a welded portion of a defective battery cell is pulled during the pulling and inspection step using the manual inspector, the number on the number display unit decreases by one, and the worker can inspect the welded portions by pulling the wire of the welded portion of all defective battery cells until the number displayed on the number display unit becomes 0.

[0030] The step of inspecting using the manual inspector may be performed by pulling a wire at a welded portion of the defective battery cell until an alarm of the manual inspector sounds.

[0031] Furthermore, the present invention can also be provided as a configuration in which the above-mentioned problems to be solved are combined in any desired manner. [Effects of the Invention]

[0032] As described above, when using the battery cell weld inspection device according to the present invention, the number of all battery cells whose welds have been determined to be defective is displayed, and the welds of the defective battery cells are directly indicated using a laser pointer, making it possible to easily identify the defective battery cells and perform a final inspection.

[0033] Furthermore, by using the battery cell weld inspection method according to the present invention, manual inspection of all defective battery cells can be performed, thereby preventing defective battery cells from being overlooked at the final inspection stage and being distributed. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a perspective view of a battery cell weld inspection device according to the present invention; [Figure 2] FIG. 2 is a partially enlarged view of FIG. [Figure 3] FIG. 2 is a plan view of the battery cell cassette. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person of ordinary skill in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0036] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0037] Furthermore, descriptions that specify or add elements are applicable to all inventions unless otherwise specified, and are not limited to a particular invention.

[0038] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0039] Furthermore, throughout the description of the present invention and the claims, unless otherwise specified, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0040] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0041] FIG. 1 is a perspective view of a battery cell weld inspection device according to the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a plan view of a battery cell cassette.

[0042] 1 to 3, the battery cell weld inspection device according to the present invention includes a plate 200 on which a battery cell cassette, in which a plurality of battery cells are arranged in a holder and a frame, is mounted; a Cartesian robot 500 that moves above the battery cell cassette fixed to the plate 200; a laser pointer 510 connected to the Cartesian robot 500 and used to indicate a defective battery cell among the plurality of battery cells; an alignment unit 300 that aligns the position of the battery cell cassette so that the battery cell cassette is positioned within the operating area of ​​the Cartesian robot 500; and a manual inspector 600 that allows an operator to manually inspect the welds of the defective battery cells indicated by the laser pointer 510.

[0043] The battery cell weld inspection device also includes a housing 100, which is a space in which components of the battery cell weld inspection device are arranged and defective welds are indicated with a laser pointer, allowing an operator to perform manual inspection.

[0044] The battery cell weld inspection device according to the present invention is used in the final stage of checking the quality of wire welds connected to the positive and negative terminals of a cylindrical battery cell. Therefore, prior to performing the final inspection using the battery cell weld inspection device according to the present invention, battery cells with defective welds are identified using a DCIR and a thermal imager, and the corresponding information is transmitted to the battery cell weld inspection device.

[0045] As such, the control unit 700 receives the internal resistance value derived from the results of measuring the voltage and current of the battery cell cassette, and the welding position information of the defective battery cell obtained from the temperature distribution results measured by the thermal image inspector, and controls the Cartesian robot.

[0046] The control unit 700 controls the Cartesian robot 500 to move in the forward / backward and left / right directions on a two-dimensional plane, and the laser pointer 510 connected to the Cartesian robot 500 irradiates a laser beam on the defective battery cell to visually indicate that it is a defective battery cell.

[0047] Specifically, as shown in FIG. 3 , when multiple battery cells 801 are mounted in a battery cell cassette 800 and wires 810 are welded to a metal plate 820, the laser pointer 510 can irradiate a laser beam onto the positive terminal welding portion where the wire is welded in the defective battery cell, as shown by the dotted circle in FIG. 3 .

[0048] Since the laser beam can be irradiated individually to the positive electrode terminal weld and / or the negative electrode terminal weld, it is possible to more specifically determine whether the positive electrode terminal weld or the negative electrode terminal weld is defective among defective battery cells.

[0049] Therefore, the present invention provides excellent visibility for an operator to identify defective battery cells for manual inspection.

[0050] In order for the laser pointer 510 to indicate the welded portion of a defective battery cell, the battery cell cassette 800 must be placed in an area that can be indicated by the laser pointer. Therefore, when the battery cell cassette 800 is placed on the plate 200, the alignment unit 300 aligns the battery cell cassette 800 so that it is placed in an area that can be indicated by the laser pointer.

[0051] Specifically, the battery cell cassette 800 includes four corner portions formed by the meeting of two side surfaces, and the alignment unit 300 aligns the battery cell cassette 800 by moving toward or away from the four corner portions.

[0052] Referring to FIG. 2, the lower end of the alignment unit 300 includes a guide 310 having a recessed groove into which the corner of the battery cell cassette 800 is inserted.

[0053] The plate 200 includes coupling portions 210 that protrude upward from the top surface to fix the position of the battery cell cassette 800. The coupling portions 210 are made up of four coupling portions 210 that are arranged adjacent to the four corners of the battery cell cassette 800. Grooves into which the coupling portions 210 can be inserted are formed on the bottom surface of the battery cell cassette 800, and the battery cell cassette 800 is placed so that the coupling portions 210 are inserted into the grooves, thereby fixing the position of the battery cell cassette.

[0054] In addition, a lift for adjusting the height of the plate 200 may be provided below the plate. After the battery cell cassette 800 is mounted on the upper surface of the plate 200, the battery cell cassette can be moved upward using the lift to the height of the alignment unit 300. Here, the battery cell cassette 800 can be maintained in a fixed position by the coupling unit 210 without shaking or moving.

[0055] The present invention includes a number display unit 400 that displays the number of defective battery cells. The control unit 700 can receive the number of defective battery cells along with their locations, and the number of defective welded battery cells is displayed numerically on the number display unit 400 so that the worker can recognize it.

[0056] Specifically, the number display unit 400 displays the number of defective welds among all the battery cells contained in the battery cell cassette 800, and displays 2 if both the positive and negative terminals of one battery cell have defective welds.

[0057] The number display unit 400 is configured to decrease the displayed number each time the worker checks a defective battery cell weld indicated by the laser pointer 510 using the manual inspector 600. For example, if the number 2 is initially displayed on the number display unit, meaning that there are two defective welds in total, the number changes to 1 when the worker completes inspection of one defective weld, and the number changes to 0 when the worker completes inspection of the remaining defective weld.

[0058] The manual tester 600 includes a push-pull jig 610 that pulls the wire at the welded portion of the defective battery cell, and an alarm unit 620 that displays an alarm when the force with which the push-pull jig 610 pulls the wire reaches a preset tension.

[0059] That is, after setting the magnitude of tension to pull the wire using the manual inspection device 600, when the push-pull jig 610 is hooked onto the wire 810 and pulled, if the tension exceeds the set magnitude, the alarm unit 620 will indicate this with sound or light, and the operator will then release the push-pull jig 610 from the wire.

[0060] For example, the magnitude of the tension can be set as a reference point corresponding to the range in which the bonding strength of the weld is normal, and manual inspection can be performed by having an operator pull the wire of the defective battery cell weld until an alarm sounds on the manual inspector 600. If the wire is released before the alarm sounds, it corresponds to a weak point and can be determined to be a defective weld, but if the wire remains attached until the alarm sounds, it can be finally determined to be a normal weld.

[0061] In this way, a battery cell cassette determined to be a defective battery cell at the final stage can be discarded or sent to a recycling process without being sent to the battery pack assembly process.

[0062] A battery cell weld inspection method using a battery cell weld inspection device according to the present invention includes the steps of placing a battery cell cassette 800, in which a plurality of battery cells are mounted, on a plate 200, aligning the position of the battery cell cassette 800 using an alignment unit 300, transmitting position information of the weld of a defective battery cell to a Cartesian robot 500, displaying the weld of the defective battery cell with a laser pointer 510 as the Cartesian robot 500 moves, and inspecting the weld of the defective battery cell displayed by the laser pointer 510 by drawing it with a manual inspector 600.

[0063] Furthermore, the information on the position of the welded portion of the defective battery cell may be obtained from the results of measuring the internal resistance of the battery cell cassette and the results of measuring with a thermal image inspection device, which have been carried out in advance.

[0064] In one specific example, when manual inspection of a specific defective battery cell among multiple defective battery cells constituting a battery cell cassette is completed, the laser beam of the laser pointer 510 indicates other defective battery cells, and when manual inspection of the other defective battery cells is completed, if there are any further defective battery cells, the laser beam can be irradiated and manual inspection can be performed on the further defective battery cells.

[0065] In this way, when manual inspection of a defective battery cell weld is completed, the laser beam moves from the previously pointed defective battery cell to another defective battery cell, visually informing the worker of the other defective battery cells. Thus, the worker can quickly and accurately confirm the overall location of the defective battery cells and perform manual inspection.

[0066] In this way, the present invention performs manual inspection only on the welds of defective battery cells based on data obtained from the battery cell cassette internal resistance measurements and thermal imaging inspection device images, thereby enabling faster and more accurate determination of the quality of defective battery cells compared to the conventional method of manually inspecting all battery cells.

[0067] Furthermore, when the battery cell weld inspection method according to the present invention is used, the number of defective welds initially displayed on the quantity display unit 400 decreases by one each time the wire of the defective battery cell weld is pulled and an alarm is generated by the alarm unit of the manual inspection unit.

[0068] The worker performs a manual inspection of all the welds indicated by the laser pointer until the number displayed on the quantity display reaches 0. This prevents defective battery cells from being omitted from the inspection when manually inspecting battery cells with defective welds according to the data.

[0069] Therefore, the present invention not only reduces the weld inspection process by not requiring full inspection of all battery cells, but also prevents defective welds from being overlooked in the final inspection stage by having an operator perform manual inspection until the number displayed on the quantity display unit reaches 0.

[0070] 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. [Explanation of symbols]

[0071] 100 Housing 200 plates 210 Joint 300 Alignment Section 310 Guide 400 Quantity Display 500 Cartesian robot 510 Laser Pointer 600 Manual Inspection Machine 610 Push-Pull Jig 620 Alarm section 700 control section 800 Battery Cell Cassette 801 Battery Cell 810 Wire 820 Metal Plate

Claims

1. a plate on which a battery cell cassette in which a plurality of battery cells are arranged is attached; an orthogonal robot that moves above the battery cell cassette fixed to the plate; a laser pointer coupled to the Cartesian robot for indicating a defective battery cell among the plurality of battery cells; an alignment unit that aligns the position of the battery cell cassette so that the battery cell cassette is placed within an operating area of ​​the Cartesian robot; A battery cell weld inspection device including: the battery cell weld inspection device further includes a manual inspector that allows an operator to manually inspect the weld of the defective battery cell indicated by the laser pointer, the manual tester includes a push-pull jig that pulls a wire at a welded portion of the defective battery cell, and an alarm unit that displays an alarm when a force that the push-pull jig pulls the wire reaches a preset magnitude; When manual inspection of a specific defective battery cell among a plurality of defective battery cells is completed, the laser beam of the laser pointer indicates other defective battery cells, and when manual inspection of the other defective battery cells is completed, if there are any further defective battery cells, the laser beam is irradiated on the further defective battery cells and manual inspection is performed by the manual inspector.

2. a plate on which a battery cell cassette in which a plurality of battery cells are arranged is attached; an orthogonal robot that moves above the battery cell cassette fixed to the plate; a laser pointer coupled to the Cartesian robot for indicating a defective battery cell among the plurality of battery cells; an alignment unit that aligns the position of the battery cell cassette so that the battery cell cassette is placed within an operating area of ​​the Cartesian robot; A battery cell weld inspection device including: the battery cell weld inspection device further includes a number display unit that displays the number of defective battery cells; the battery cell weld inspection device further includes a manual inspector that allows an operator to manually inspect the weld of the defective battery cell indicated by the laser pointer, the manual tester includes a push-pull jig that pulls a wire at a welded portion of the defective battery cell, and an alarm unit that displays an alarm when a force that the push-pull jig pulls the wire reaches a preset magnitude; the number displayed on the number display unit decreases each time the operator checks the weld of a defective battery cell indicated by the laser pointer using the manual inspector, and the manual inspector continues to inspect the welds of all defective battery cells until the number displayed on the number display unit reaches 0.

3. 3. The battery cell weld inspection device according to claim 1, further comprising a control unit that receives information on the internal resistance value of the battery cell cassette and the position of the weld of a defective battery cell derived from the measurement results of the thermal image inspection device and controls the Cartesian robot.

4. 3. The battery cell weld inspection device according to claim 1, wherein the laser pointer irradiates a laser beam onto the welds of the positive and negative terminals of a defective battery cell.

5. a lift for adjusting the height of the plate; The battery cell weld inspection device according to claim 1 or 2, wherein the lift is located below the plate.

6. the battery cell cassette includes four corners formed by two side surfaces meeting, The battery cell weld inspection device according to claim 1 or 2, wherein the alignment unit aligns the battery cell cassette while moving toward or away from the four corner portions.

7. The battery cell weld inspection device according to claim 1 or 2, wherein the plate includes a connecting portion for fixing the position of the battery cell cassette.

8. A battery cell weld inspection method using a battery cell weld inspection device, comprising: The battery cell weld inspection device includes: a plate on which a battery cell cassette in which a plurality of battery cells are arranged is attached; an orthogonal robot that moves above the battery cell cassette fixed to the plate; a laser pointer coupled to the Cartesian robot for indicating a defective battery cell among the plurality of battery cells; an alignment unit that aligns the position of the battery cell cassette so that the battery cell cassette is placed within an operating area of ​​the Cartesian robot; Including, The battery cell weld inspection method includes: placing a battery cell cassette having a plurality of battery cells mounted therein on a plate; aligning the position of the battery cell cassette using an alignment unit; transmitting information about the position of the welded portion of the defective battery cell to the Cartesian robot; indicating a welded portion of a defective battery cell with a laser pointer according to the movement of the Cartesian robot; inspecting the welded portion of the defective battery cell indicated by the laser pointer by pulling it with a manual inspector; Including, The information on the position of the welded portion of the defective battery cell is obtained from the results of a measurement of the internal resistance of the battery cell cassette and a measurement result of a thermal imaging inspection device that have been carried out in advance, When manual inspection of a specific defective battery cell among the plurality of defective battery cells is completed, the laser beam of the laser pointer indicates other defective battery cells; When the manual inspection of the other defective battery cell is completed, if there is still another defective battery cell, the laser beam is irradiated on the still another defective battery cell and a manual inspection is performed.

9. A battery cell weld inspection method using a battery cell weld inspection device, comprising: The battery cell weld inspection device includes: a plate on which a battery cell cassette in which a plurality of battery cells are arranged is attached; an orthogonal robot that moves above the battery cell cassette fixed to the plate; a laser pointer coupled to the Cartesian robot for indicating a defective battery cell among the plurality of battery cells; an alignment unit that aligns the position of the battery cell cassette so that the battery cell cassette is placed within an operating area of ​​the Cartesian robot; Including, The battery cell weld inspection method includes: placing a battery cell cassette having a plurality of battery cells mounted therein on a plate; aligning the position of the battery cell cassette using an alignment unit; transmitting information about the position of the welded portion of the defective battery cell to the Cartesian robot; indicating a welded portion of a defective battery cell with a laser pointer according to the movement of the Cartesian robot; inspecting the welded portion of the defective battery cell indicated by the laser pointer by pulling it with a manual inspector; Including, The information on the position of the welded portion of the defective battery cell is obtained from the results of a measurement of the internal resistance of the battery cell cassette and a measurement result of a thermal imaging inspection device that have been carried out in advance, The number of the defective battery cells is displayed numerically on the number display unit, In the step of pulling and inspecting with the manual inspector, the number on the quantity display unit is decreased by one each time the wire of the welding portion of the defective battery cell is pulled, The battery cell weld inspection method comprises the steps of: an operator inspecting the welds of all defective battery cells by pulling the wires of the welds until the number displayed in the quantity display unit reaches 0;

10. 10. The battery cell weld inspection method according to claim 8, wherein the inspecting step using the manual inspector is performed by pulling a wire of the weld of the defective battery cell until an alarm of the manual inspector sounds.

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