Electric vehicle battery case manufacturing method

An electric vehicle battery case manufacturing method comprising:

• a first cycle performing operation 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),
• wherein the unit assembly preparing step (S1) performs a process of preparing unit parts, making up sub-assemblies, through aluminum extrusion and initial 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 then performing metal inert gas (MIG) welding,
• the first machining step (S3) performs a process of performing machining or hole machining on a welding bead part formed by the MIG welding when the MIG welding is performed 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 having a surface corrected by the first machining step (S3) when the MIG welding is performed,
• a second cycle performing operation of sequentially performing a second welding step (S5), a second machining step (S10), a third welding step (S11), and a second inspection step (S12) that is performed after the first cycle performing operation,
• wherein the second welding step (S5) performs a process of performing friction stir welding (FSW) and laser welding on the product that has passed through the first inspection step (S4),
• the second machining step (S10) performs a process of performing final surface machining on the welding bead part and the distorted surface of the product assembled through the second welding step (S5) and then performing final hole machining at a designed position,
• the third welding step (S11) performs a process of performing pipe MIG welding on the product produced through the second machining step (S10), and
• the second inspection step (S12) performs a process of conducting a leak test on the product completed through the third welding step (S11),
• a complete product providing step (S15) including packaging and providing the product as the electric vehicle battery case.