Door inner panel for automobile and method of manufacturing same

摘要

A door inner panel as automobile parts is manufactured from a tailor welded blank formed from a different thickness steel sheet by means of different thickness connection for connecting different kind steel sheets having different sheet thicknesses. In the tailor welded blank, a weld line of the tailor welded blank includes linear weld line portions and a curved weld line portion through which the linear weld lines are connected.

主权项

1. A method for manufacturing a door inner panel for an automobile, comprising the steps of:
preparing two different steel sheets comprising a thin sheet and a thick sheet, the thin sheet having a cutout portion with a curved portion, and the thick sheet being arranged in the cutout portion of the thin sheet; overlapping the thin sheet and the thick sheet at the curved portion to form an overlap margin portion; performing butt welding between linear portions of the cutout portion of the thin sheet and the thick sheet to form linear weld line portions; and performing lap welding at the overlap margin portion between the thin sheet and the thick sheet to connect the linear weld line portions via a curved weld line portion to thereby form a different thickness steel sheet as a tailor welded blank.