US Patent 11198406 Grille shutter

A fragile portion is provided at a portion of a vertical frame bar. When an impact load from under a vehicle is applied to a grille shutter, the impact can be at least partially absorbed as the fragile portion undergoes plastic deformation (including damage). Thus, the impact exerted on a portion of the vertical frame bar other than the fragile portion is mitigated, and a fin can be restrained from coming off a frame. Moreover, the fin can be restrained from coming off the frame by a compact structure, because simply providing the fragile portion at a portion of the vertical frame bar can achieve that.