Electric vehicle battery case manufacturing method

Abstract

To providing an electric vehicle battery case manufacturing method that can ensure high quality of the final product.SOLUTION: An electric vehicle battery case manufacturing method includes a first cycle performing step of sequentially performing a unit assembly preparing step S1, a first welding step S2, a first machining step S3, and a first inspection step S4. Therein: the unit assembly preparing step S1 performs a process of preparing unit parts through aluminum extrusion and machining and then welding each sub-assembly; the first welding step S2 performs a process of assembling the sub-assemblies produced through the unit assembly preparing step S1 and, after the assembly of the sub-assemblies, performing metal inert gas (MIG) welding or friction stir welding (FSW); the first machining step S3 performs a process of performing machining or hole machining on a welding bead part and a distorted surface of a product assembled through the first welding step S2; and the first inspection step S4 performs a process of conducting a leak test on the product corrected through the first machining step S3.SELECTED DRAWING: Figure 2a

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a battery case for an electric vehicle, and more particularly, to a method for manufacturing a battery case for an electric vehicle, which can prevent welding deformation that occurs during welding of a hole-processed profile. [Background technology]

[0002] In the case of electric vehicle battery cases using conventional technology, each part of the extruded profile is subjected to surface processing and hole processing, and then each part is combined through MIG welding and FSW welding to complete one electric vehicle battery case.

[0003] Specifically, the surface processing and hole processing of the subparts are performed first, and the welding deformation that occurs during the final welding process that follows often means that the designed dimensional tolerances cannot be met. In order to eliminate defects caused by such welding deformation, a process to correct the deformation is added as a post-welding process.

[0004] As a result, the conventional method for manufacturing a battery case for an electric vehicle has problems of increased man-hours due to a calibration process caused by welding deformation, increased manufacturing time, and increased manufacturing costs.

[0005] As a specific example, in the case of an electric vehicle battery case made of aluminum material, the heat generated during welding of the holes and processed profiles causes distortion. The distortion causes tolerance deviation and flatness problems in the processed holes, affecting the quality of the entire product when assembling the battery system assembly (final product) and the lower and upper panels. In addition, it also affects the automation of riveting work on about 300 holes during the production of the battery case, causing problems with production efficiency.

[0006] Therefore, there is a need for a technology that can solve the problems of the conventional technology. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-243269 (Registration Date: August 10, 2022) Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a method for manufacturing a battery case for an electric vehicle, which can stabilize the flatness of parts in the manufacturing process of a battery case for an electric vehicle, stabilize the hole processing tolerance, prevent defects and production losses occurring during the manufacturing process of a battery case for an electric vehicle, automate the subsequent riveting process, reduce not only the disposal cost of defective products but also the production cost, and ensure high quality of the final product. [Means for solving the problem]

[0009] To achieve this object, a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention includes a first cycle execution step of sequentially executing a unit assembly preparation step S1, a first welding step S2, a first processing step S3, and a first inspection step S4, in which the unit assembly preparation step S1 performs a process of preparing unit parts by aluminum extrusion and machining, and then welding each sub-assembly, the first welding step S2 performs a process of performing MIG welding or FSW welding after assembling the sub-assemblies manufactured through the unit assembly preparation step S1, the first processing step S3 performs a process of processing a weld bead portion and a twisted surface of a product assembled through the first welding step S2, or processing holes, and the first inspection step S4 may perform a process of performing a leak test on a product corrected through the first processing step S3.

[0010] In one embodiment of the present invention, the method for manufacturing a battery case for an electric vehicle includes a second cycle performing step of sequentially performing a second welding step S5, a second processing step S10, a third welding step S11, and a second inspection step S12, which are performed after the first cycle performing step. The second welding step S5 performs a process of performing FSW welding and laser welding on a product that has passed the first inspection step S4. The second processing step S10 performs a process of performing final surface processing on a weld bead portion and a twisted surface of a product assembled through the second welding step S5, and then performing final hole processing at a designed position. The third welding step S11 performs a process of performing pipe MIG welding on a product manufactured through the second processing step S10. The second inspection step S12 may perform a leak test on a product completed through the third welding step S11.

[0011] In an embodiment of the present invention, the method for manufacturing an electric vehicle battery case may further include a product fastening step of assembling the product that has passed the second inspection step by riveting and screwing, a final inspection step of inspecting a product completed through the product fastening step, and a finished product shipping step of packaging and shipping the product that has passed the final inspection step.

[0012] In one embodiment of the present invention, the first welding step can manufacture one frame structure by using a MIG welding method or an FSW welding method to weld the left and right member body side sub-assemblies, the rear member body sub-assembly, and the bracket module mounting sub-assembly.

[0013] In this case, the first processing step may include an upper weld bead processing step of processing an upper weld bead of the frame frame structure manufactured through the first welding step, a lower weld bead processing step of processing a lower weld bead of the frame frame structure after performing the upper weld bead processing step, and an air blow step of cleaning the processed surface using compressed air after performing the lower weld bead processing step.

[0014] In one embodiment of the present invention, the second welding step may include a bracket welding step of assembling a plurality of bracket module mounting sub-assemblies and a plurality of bracket swelling block sub-assemblies to a frame-frame structure using a MIG welding method; a lower sealing plate welding step of assembling a lower sealing plate to a lower surface of the frame-frame structure manufactured through the bracket welding step using a laser welding method; a lower sealing plate assembly state inspection step of inspecting an assembled state of the frame-frame structure manufactured through the lower sealing plate welding step; an FSW welding step of final welding a MIG welded portion and a laser welded portion to the frame-frame structure that has passed the inspection step using an FSW welding method; and an FSW weld portion finishing and inspection step of finishing the FSW welded portion after the FSW welding step and inspecting the finished surface.

[0015] In one embodiment of the present invention, the finished product shipping step may include a lower surface cover member preparation step of manufacturing a lower surface cover member having a structure capable of sealing the upper surface of the frame structure; a lower surface cover member fixing step of attaching the lower surface cover member to the upper surface of the frame structure and then fastening it using an FDS screw; an air blow and Z-face inspection step of cleaning the product that has passed the cover member fixing step using compressed air and then inspecting the upper and lower surfaces; and a vision inspection and laser marking step of performing a final inspection by vision inspection on the product that has passed the air blow and Z-face inspection steps and then marking it using a laser. Effect of the Invention

[0016] As described above, according to the method for manufacturing an electric vehicle battery case of the present invention, by sequentially performing the step of preparing a unit assembly for performing a specific process, the first welding step, the first processing step, and the first inspection step, welding, which generates welding distortion, is performed first, and then face processing and hole processing are performed. This makes it possible to prevent the source of welding distortion, poor surface processing dimensional defects, and poor hole processing dimensional defects that occur in conventional technologies, and to eliminate the man-hours invested in correcting the poor surface processing dimensional defects and poor hole processing dimensional defects. As a result, it is possible to provide a method for manufacturing an electric vehicle battery case that not only ensures the efficiency of the manufacturing process and reduces the manufacturing cost, but also guarantees the high quality of the final product. [Brief description of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a product manufactured through a method for manufacturing a battery case for an electric vehicle according to an embodiment of the present invention; [Figure 2a] 3 is a flowchart illustrating a method for manufacturing a battery case for an electric vehicle according to an embodiment of the present invention. [Figure 2b] 5 is a flowchart illustrating a method for manufacturing a battery case for an electric vehicle according to another embodiment of the present invention. [Diagram 3] 2c is a flowchart showing in more detail the second welding step of the manufacturing method for an electric vehicle battery case shown in FIG. 2b. [Figure 4] 4 is a flowchart showing a product fastening step, a final inspection step, and a finished product shipping step of a method for manufacturing a battery case for an electric vehicle according to an embodiment of the present invention. [Diagram 5] 1 is a process diagram illustrating a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. FIG. [Figure 6] FIG. 2 is a process schematic diagram showing a unit assembly preparation step S1 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 7] FIG. 4 is a process schematic diagram showing a first welding step S2 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 8] FIG. 4 is a process schematic diagram showing a first processing step S3 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 9] FIG. 4 is a process schematic diagram showing a first inspection step S4 of a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 10] FIG. 11 is a process schematic diagram showing a bracket welding step S5-1 that constitutes the second welding step S5 of the method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 11] 10 is a process schematic diagram showing a lower sealing plate welding step S6 constituting a second welding step S5 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. FIG. [Figure 12] 10 is a process schematic diagram showing a lower sealing plate assembly state inspection step S7 which constitutes the second welding step S5 of the method for manufacturing an electric vehicle battery case according to one embodiment of the present invention. FIG. [Figure 13] FIG. 11 is a process schematic diagram showing an FSW welding step S8 constituting a second welding step S5 of a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 14] FIG. 11 is a process schematic diagram showing an FSW welded portion finishing and inspection step S9 that constitutes the second welding step S5 of the method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 15] FIG. 4 is a process schematic diagram showing a second processing step S10 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 16] FIG. 4 is a process schematic diagram showing a third welding step S11 of a method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 17] FIG. 4 is a process schematic diagram showing a second inspection step S12 of a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 18] FIG. 4 is a process schematic diagram showing a product fastening step S13 in a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 19]FIG. 4 is a process schematic diagram showing a final inspection step S14 of a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 20] FIG. 11 is a process schematic diagram showing a lower surface cover member preparation step S15-1 that constitutes the finished product shipping step S15 of the method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 21] FIG. 11 is a process schematic diagram showing a cover member fixing step S16 that constitutes the finished product shipping step S15 in the method for manufacturing a battery case for an electric vehicle according to one embodiment of the present invention. [Figure 22] FIG. 11 is a process schematic diagram showing an air blowing and Z-face inspection step S17 constituting a finished product shipping step S15 in a manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. [Figure 23] FIG. 13 is a process schematic diagram showing a vision inspection and laser marking step S18 that constitutes the finished product shipping step S15 of the manufacturing method for an electric vehicle battery case according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Prior to this, the terms and words used in the present specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that correspond to the technical ideas of the present invention.

[0019] Throughout this specification, when a member is said to be located "on" another member, this includes not only when the member is in contact with the other member, but also when there is another member between the two members. Throughout this specification, when a part is said to "include" a certain component, this does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0020] FIG. 1 is a perspective view showing a product manufactured through a method for manufacturing a battery case for an electric vehicle according to an embodiment of the present invention, and FIGS. 2a and 2b are a flowchart showing a method for manufacturing a battery case for an electric vehicle according to an embodiment of the present invention.

[0021] 14. Referring to these drawings, the manufacturing method S100 for an electric vehicle battery case according to the present embodiment sequentially performs a unit assembly preparation step S1 for performing a specific process, a first welding step S2, a first processing step S3, a first inspection step S4, a second welding step S5, a second processing step S10, a third welding step S11, and a second inspection step S12. This allows welding, which generates welding deformation, to be performed first, and then surface processing and hole processing to be performed. This prevents welding deformation, poor surface processing dimensional defects, and poor hole processing dimensional defects that occur in conventional technologies from occurring at the source, and eliminates the labor hours required to correct poor surface processing dimensional defects and poor hole processing dimensional defects. As a result, it is possible to provide a manufacturing method for an electric vehicle battery case that not only ensures the efficiency of the manufacturing process and reduces the manufacturing cost, but also guarantees the high quality of the final product.

[0022] Hereinafter, each step constituting the method S100 for manufacturing a battery case for an electric vehicle according to this embodiment will be described in detail with reference to the drawings.

[0023] FIG. 3 is a flowchart showing in more detail the second welding step of the method for manufacturing an electric vehicle battery case shown in FIG. 2b. FIG. 4 is a flowchart showing the product fastening step, final inspection step, and finished product shipping step of the method for manufacturing an electric vehicle battery case according to one embodiment of the present invention. FIG. 5 is a process schematic diagram showing the method for manufacturing an electric vehicle battery case according to one embodiment of the present invention.

[0024] 1. Referring to these figures, in the unit assembly preparation step S1 according to this embodiment, unit parts are prepared by aluminum extrusion and machining, and then each sub-assembly is welded.

[0025] In the first welding step S2 according to the present embodiment, MIG welding or FSW welding is performed after assembling the sub-assemblies manufactured through the unit assembly preparation step S1.

[0026] In the first processing step S3 according to the present embodiment, a process of processing and correctly correcting the weld bead portion and twist surface of the product assembled through the first welding step S2 is performed.

[0027] In the first inspection step S4 according to the present embodiment, a leak test is performed on the product corrected through the first processing step S3.

[0028] In the second welding step S5 according to this embodiment, FSW welding and laser welding are performed on the product that has passed the first inspection step S4.

[0029] In the second processing step S10 according to this embodiment, the final surface processing is performed on the weld bead portion and twist surface of the product assembled through the second welding step S5, and then a final hole is processed at a designed position.

[0030] In the third welding step S11 according to the present embodiment, pipe MIG welding is performed on the product manufactured through the second processing step S10.

[0031] In the second inspection step S12 according to the present embodiment, a leak test is performed on the product completed through the third welding step S11.

[0032] As shown in FIGS. 4 and 5, the method S100 for manufacturing an electric vehicle battery case according to the present embodiment may further include a product fastening step S13 for performing a specific process, a final inspection step S14, and a finished product shipping step S15.

[0033] Specifically, the product fastening step S13 according to the present embodiment involves a process of assembling the product that has passed the second inspection step S12 by riveting and screw fastening.

[0034] The final inspection step S14 according to the present embodiment is a process of inspecting the product completed through the product fastening step S13.

[0035] In addition, a finished product shipping step S15 involves packaging and shipping the products that have passed the final inspection step S14.

[0036] 6 to 23 are process schematic diagrams showing the individual steps of a method S100 for manufacturing a battery case for an electric vehicle.

[0037] Each step will be described in detail below with reference to the respective step schematic diagrams.

[0038] The first welding step S2 in this embodiment, as shown in Figures 2b, 5 and 7, involves the process of manufacturing one frame structure 10 using a MIG welding method for the left and right member body side sub-assemblies, the rear member body sub-assembly and the bracket module mounting sub-assembly.

[0039] In the first processing step S3 according to the present embodiment, as shown in Figures 2b, 5 and 8, an upper weld bead processing step is performed to process an upper weld bead of the frame frame structure 10 manufactured through the first welding step S2. After that, after the upper weld bead processing step, a lower weld bead processing step is performed to process a lower weld bead of the frame frame structure 10, and after the lower weld bead processing step, an air blow step is performed to clean the processed surface using compressed air.

[0040] The second welding step S5 according to this embodiment may include a bracket welding step S5-1 for performing a specific process, a lower sealing plate welding step S6, a lower sealing plate assembly state inspection step S7, an FSW welding step S8, and an FSW weld finishing and inspection step S9, as shown in Figures 2b, 3, 5, and 9 to 14.

[0041] Specifically, the bracket welding step S5-1 of the second welding step S5 assembles a plurality of bracket module mounting sub-assemblies and a plurality of bracket swelling blocking sub-assemblies to the frame frame structure 10 using the MIG welding method. The lower sealing plate welding step S6 of the second welding step S5 assembles the lower sealing plate 20 to the lower surface of the frame frame structure 10 manufactured through the bracket welding step S5-1 using the laser welding method. The lower sealing plate assembly state inspection step S7 of the second welding step S5 inspects the assembled state of the frame frame structure 10 manufactured through the lower sealing plate welding step S6. The FSW welding step S8 of the second welding step S5 performs a final welding process on the MIG welded portion and the laser welded portion of the frame frame structure 10 that has passed the inspection step using the FSW welding method. In addition, the FSW welded portion finishing and inspection step S9 of the second welding step S5 inspects the finished surface after finishing the FSW welded portion after performing the FSW welding step S8.

[0042] The finished product shipping step S15 in this embodiment may include a lower surface cover member preparation step S15-1 performing a specific process, a cover member fixing step S16, an air blowing and Z surface inspection step S17, and a vision inspection and laser engraving step S18, as shown in Figures 4, 5, and 20 to 23.

[0043] Specifically, the cover member preparation step S15-1 of the finished product shipping step S15 performs a process of manufacturing a lower surface cover member 30 having a structure capable of sealing the upper surface of the frame-frame structure 10. The cover member fixing step S16 of the finished product shipping step S15 performs a process of attaching the lower surface cover member 30 to the upper surface of the frame-frame structure 10 and then fastening it using FDS screws. The air blowing and Z-face inspection step S17 of the finished product shipping step S15 performs a process of cleaning the product that has passed the cover member fixing step S16 using compressed air and then inspecting the upper and lower surfaces. In addition, the vision inspection and laser marking step S18 of the finished product shipping step S15 performs a process of performing a final inspection by vision inspection on the product that has passed the air blowing and Z-face inspection step S17 and then marking it using a laser.

[0044] As described above, according to the method for manufacturing an electric vehicle battery case of the present invention, by sequentially performing the unit assembly preparation step S1 for performing a specific process, the first welding step S2, the first processing step S3, the first inspection step S4, the second welding step S5, the second processing step S10, the third welding step S11 and the second inspection step S12, welding that generates welding deformation is performed first, and then face processing and hole processing are performed. This makes it possible to prevent the welding deformation, poor surface processing dimensional defects and poor hole processing dimensional defects that occur in the conventional technology at the source and to eliminate the man-hours invested in correcting the poor surface processing dimensional defects and poor hole processing dimensional defects. As a result, it is possible to provide a method for manufacturing an electric vehicle battery case that not only ensures the efficiency of the manufacturing process and reduces the manufacturing cost, but also guarantees the high quality of the final product.

[0045] In the above detailed description of the present invention, only specific embodiments thereof have been described, but it is to be understood that the present invention is not limited to the specific forms set forth in the detailed description, but rather includes all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

[0046] In other words, the present invention is not limited to the specific embodiments and explanations described above, and various modifications can be made by anyone having ordinary knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims, and such modifications are within the scope of protection of the present invention. [Explanation of symbols]

[0047] 100: Battery case for electric vehicles 10: Frame structure 20: Lower sealing plate 30: Lower surface cover member S100: Manufacturing method for battery cases for electric vehicles S1: Unit assembly preparation step S2: First welding step S3: First processing step S4: First inspection step S5: Second welding step S5-1: Bracket welding step S6: Lower sealing plate welding step S7: Lower sealing plate assembly status inspection step S8: FSW welding step S9: FSW weld finishing and inspection steps S10: Second processing step S11: 3rd welding step S12: Second inspection step S13: Product Conclusion Step S14: Final inspection step S15: Finished product shipping step S15-1: Lower surface cover material preparation step S16: Cover material fixing step S17: Air blow and Z-surface inspection step S18: Vision inspection and laser marking step

Claims

1. As a method for manufacturing a battery case for an electric vehicle, The method includes a first cycle execution step of sequentially executing a unit assembly preparation step S1, a first welding step S2, a first processing step S3, and a first inspection step S4, The unit assembly preparation step S1 includes a process of preparing unit parts by aluminum extrusion and machining, and then welding each sub-assembly. The first welding step S2 is a process of performing MIG welding or FSW welding after assembling the sub-assemblies manufactured through the unit assembly preparation step S1, The first processing step (S3) is a process of processing a weld bead portion and a twisted surface of a product assembled through the first welding step (S2) or processing a hole. The first inspection step (S4) includes a process of performing a leak test on the product corrected through the first processing step (S3).

2. The method for manufacturing a battery case for an electric vehicle includes: The method includes a second cycle execution step of sequentially executing a second welding step S5, a second processing step S10, a third welding step S11, and a second inspection step S12, which are performed after the first cycle execution step; The second welding step (S5) is a process of performing FSW welding and laser welding on the product that has passed the first inspection step (S4), The second processing step S10 performs a process of performing final surface processing of the weld bead portion and twist surface of the product assembled through the second welding step S5, and then performing final hole processing at a designed position. The third welding step (S11) is a process of performing pipe MIG welding on the product manufactured through the second processing step (S10), 2. The method of claim 1, wherein the second inspection step (S12) comprises performing a leak test on a product completed through the third welding step (S11).

3. The method for manufacturing a battery case for an electric vehicle includes: a product fastening step S13 in which the products that have passed the second inspection step S12 are assembled by riveting and screw fastening; a final inspection step (S14) for inspecting the product completed through the product fastening step (S13); 3. The method of claim 2, further comprising a finished product shipping step (S15) of packaging and shipping the product that has passed the final inspection step (S14).

4. The first welding step S2 includes: The left and right member body side sub-assemblies, the rear member body sub-assembly and the bracket module mounting sub-assembly are fabricated into one frame structure 10 by using a MIG welding method or a FSW welding method; The first processing step S3 is an upper weld bead processing step of processing an upper weld bead of the frame structure 10 manufactured through the first welding step S2; a lower weld bead processing step of processing a lower weld bead of the frame frame structure 10 after the upper weld bead processing step; 4. The method for manufacturing a battery case for an electric vehicle according to claim 3, further comprising: an air blowing step of cleaning the processed surface with compressed air after the lower weld bead processing step.

5. The second welding step S5 includes: a bracket welding step S5-1 for assembling a plurality of bracket module mounting subassemblies and a plurality of bracket swelling blocking subassemblies to the frame structure 10 using a MIG welding method; A lower sealing plate welding step S6 is a step of assembling the lower sealing plate 20 to the lower surface of the frame structure 10 manufactured through the bracket welding step S5-1 by using a laser welding method; a lower sealing plate assembly state inspection step (S7) for inspecting the assembly state of the frame-frame structure 10 manufactured through the lower sealing plate welding step (S6); a FSW welding step S8 in which the MIG welded portion and the laser welded portion of the frame structure 10 that has passed the inspection step are subjected to a final welding process using a FSW welding method; 5. The method for manufacturing a battery case for an electric vehicle according to claim 4, further comprising: an FSW welded portion finishing and inspection step S9 for inspecting the finished surface of the FSW welded portion after the FSW welding step S8 is performed.

6. The completed product shipping step S15 is A lower surface cover member preparation step S15-1 for preparing a lower surface cover member 30 having a structure capable of sealing the upper surface of the frame structure 10; a lower surface cover member fixing step S16 in which the lower surface cover member 30 is attached to the upper surface of the frame structure 10 and then fastened using FDS screws; After the product that has passed through the cover member fixing step S16 is cleaned using compressed air, an air blow and Z-face inspection step S17 is performed to inspect the upper and lower faces. The method for manufacturing a battery case for an electric vehicle according to claim 4, further comprising a vision inspection and laser marking step S18 in which a product that has passed the air blow and Z-face inspection step S17 is subjected to a final inspection by vision inspection, and then stamped with a laser.

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