Aluminum alloy doors are relatively heavy, and the material strength is limited. After a long time, due to the action of gravity, they are easy to deform and sag, resulting in dislocation of door locks and inability to align. This is a common problem, which is not easy to solve, and belongs to the congenital deficiency of design (caused by quadrilateral instability). It has been installed and used. If you don't want to replace it, the only remedy is to fix a cable on the diagonal of the door with steel wire to correct the drooping door frame, which is also a very effective method. (If it doesn't look good, you can operate it below according to the picture on the right. If possible, it is best to replace the baffle at the lower part of the door with a whole piece, which can also reduce sagging. )