摘要 |
Extending portions of a front sub-frame are each formed by stacking two thin plates made of steel, and flange portions of the front sub-frame and flange portions of a rear sub-frame made of aluminum are superimposed on each other, and are friction stir welded, with a seal material applied to the superimposed surfaces. Of the two thin plates, the thin plate joined to the rear sub-frame made of aluminum has, at each end thereof, a bent portion and an extending part. The bent portion is formed by bending. The end of the extending part extends outward farther than the rear sub-frame. The extending part is covered by the seal material. The bent portion is disposed at a farther end of the extending part. |