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KR-102964185-B1 - Welding Method For Automotive Sheets To Reduce Flange Length

KR102964185B1KR 102964185 B1KR102964185 B1KR 102964185B1KR-102964185-B1

Abstract

A welding method for automotive sheet metal for shortening flange length according to a disclosed embodiment is, In a method for welding automotive sheet metal to shorten the flange length, A step (S110) of forming at least two protrusions (300) between an upper base material (100) and a lower base material (200); a step (S120) of joining an electrode (400) to the upper base material (100) and the lower base material (200); a step (S130) of applying a first electrode pressure and a first welding current to at least one of the upper base material (100) and the lower base material (200) to collapse the protrusions (300); a step (S140) of applying a second electrode pressure and a second welding current to at least one of the upper base material (100) and the lower base material (200) to melt the protrusions (300). The method may be configured to include: a step (S150) of applying a third electrode pressure and a third welding current to at least one of the upper base material (100) and the lower base material (200) to form at least two spaced-apart first nuggets (500) between the upper base material (100) and the lower base material (200); and a step (S160) of applying a fourth electrode pressure and a fourth welding current to at least one of the upper base material (100) and the lower base material (200) to grow the first nuggets (500) and form a combined second nugget (600).

Inventors

  • 박영도
  • 테자스윈 크리슈나
  • 닐리코드 사브야사치

Assignees

  • 동의대학교 산학협력단

Dates

Publication Date
20260513
Application Date
20240222

Claims (5)

  1. In a method for welding automotive sheet metal to shorten the flange length, A step (S110) of forming at least two protrusions (300) between an upper base material (100) and a lower base material (200); Step (S120) of combining an electrode (400) with the upper base material (100) and the lower base material (200); A step (S130) of applying a first electrode pressure and a first welding current to at least one of the upper base material (100) and the lower base material (200) to collapse the protrusion (300); A step (S140) of melting the protrusion (300) by applying a second electrode pressure and a second welding current to at least one of the upper base material (100) and the lower base material (200); A step (S150) of applying a third electrode pressure and a third welding current to at least one of the upper base material (100) and the lower base material (200) to form at least two spaced-apart first nuggets (500) between the upper base material (100) and the lower base material (200); and The method includes the step (S160) of applying a fourth electrode pressure and a fourth welding current to at least one of the upper base material (100) and the lower base material (200) to grow the first nugget (500) and form a combined second nugget (600). The contact cross-sectional area between the electrode (400), the upper base material (100), and the lower base material (200) is larger than the contact cross-sectional area between the protrusion (300), the upper base material (100), and the lower base material (200). The contact portion (410) of the above electrode (400) is in the shape of a cuboid, and At least one of the first to fourth welding currents has an upslope waveform, and At least one of the first to fourth electrode pressures has a pressure waveform that is in the form of a downslope, and The above protrusion (300) is formed in a shape in which the horizontal cross-sectional area decreases in the downward direction, and The above protrusion (300) is formed in a conical shape downward from the lower surface of the upper base material (100), and A welding method for automobile sheet metal for shortening flange length, characterized in that the sum of the radii of the contact cross-sectional area between the protrusions (300) and the base material (100, 200) relative to the center distance between the protrusions (300) is 0.55 or more and 0.65 or less.
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Description

Welding Method For Automotive Sheets To Reduce Flange Length The contents disclosed in this specification relate to a welding method, and more specifically, to a welding method for automotive sheet metal for shortening the flange length. Resistance welding refers to a welding method that utilizes resistance heating by applying electrical heat and mechanical load using an electrode through which electricity flows. Projection welding is a type of resistance welding in which an electrode presses against protrusions formed on the parts to be joined and concentrates the current to achieve welding through the resistance heating of the material itself. Projection welding has the advantages of being suitable for welding thick metal plates, offering excellent shear and tensile strength, and enabling visually superior weld quality due to low weld visibility; however, it also has the disadvantage that it is difficult to control the resistance heat generated by the projections. Meanwhile, the car body is composed of multiple metal plates, and the part that fixes them together is called a flange, and the car body is composed of multiple flanges. There is a need for a welding method that can reduce weight while preserving the shear and tensile strength of the car body. However, conventional resistance spot welding has the problem that the shear strength of the weld is significantly lowered, and in the case of projection welding, if the process is not precisely controlled, spatter is scattered, causing a problem of reduced shear strength of the weld. FIG. 1 is a flowchart for explaining a welding method for automobile sheet metal for shortening flange length according to an embodiment of the present disclosure, FIGS. 2 to 5 are drawings for specifically explaining a welding method for automobile sheet metal for shortening the flange length according to an embodiment of the present disclosure, FIGS. 6 to 10 are drawings for explaining a comparison between welding by a welding method according to an embodiment of the present disclosure and welding by a comparative example, resistance spot welding. Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but this is for the purpose of facilitating understanding of the present disclosure and the present disclosure is not limited thereto. In the present disclosure, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. FIG. 1 is a flowchart for explaining a welding method for automobile sheet metal for shortening the flange length according to an embodiment of the present disclosure, FIG. 2 to 5 are drawings for specifically explaining a welding method for automobile sheet metal for shortening the flange length according to an embodiment of the present disclosure, and FIG. 6 to 10 are drawings for explaining a comparison between welding by the welding method according to an embodiment of the present disclosure and welding by resistance spot welding, which is a comparative example. <Automotive sheet metal welding method for shortening flange length according to an embodiment of the present disclosure> Referring to FIGS. 1 to 5, the automobile sheet metal welding method for shortening the flange length according to an embodiment of the present disclosure is an automobile sheet metal welding method for shortening the flange length, wherein A step (S110) of forming at least two protrusions (300) between an upper base material (100) and a lower base material (200); a step (S120) of joining an electrode (400) to the upper base material (100) and the lower base material (200); a step (S130) of applying a first electrode pressure and a first welding current to at least one of the upper base material (100) and the lower base material (200) to collapse the protrusions (300); a step (S140) of applying a second electrode pressure and a second welding current to at least one of the upper base material (100) and the lower base material (200) to melt the protrusions (300). The method may be configured to include: a step (S150) of applying a third electrode pressure and a third welding current to at least one of the upper base material (100) and the lower base material (200) to form at least two spaced-apart first nuggets (500) between the upper base material (100) and the lower base material (200); and a step (S160) of applying a fourth electrode pressure and a fourth welding current to at least one of the upper base material (100) and the lower base material (200) to grow the first nuggets (500) and form a combined second nugget (600). The upper base material (100) and the lower base material (200) may be the same metal (or composite alloy) or, without limitation, different components such as carbon, steel, aluminum, and copper. Referring to FIG. 2, in the step (S110) of forming at least two protrusions (300) be