Automatic punching machine for metal bottle caps

The invention discloses an automatic punching machine for metal bottle caps, and relates to the technical field of punching equipment. A transfer unit; a feeding device; the feeding device comprises a bearing table, a mounting frame, a mechanical feeding arm, a cleaning roller and a driving assembly. The bearing table is arranged on the side, away from the stamping machine body, of the conveying part, and the mounting frame is arranged on the bearing table; the mechanical feeding arm is arranged on the mounting frame and adsorbs the metal plates in the waiting area to the conveying part; the cleaning roller slides above the material waiting area in the horizontal direction, and cleaning bristles in sliding contact with the surface of the metal plate are arranged on the peripheral side of the cleaning roller. When the mechanical feeding arm downwards adsorbs the metal plate, the driving assembly drives the cleaning roller to slide in the direction away from the stamping machine body to be separated from the me