Cleaning mechanism used before paperboard printing

The utility model relates to a cleaning mechanism used before paperboard printing. The cleaning mechanism comprises a portal frame, a lifting air cylinder, a lifting wheel frame, a cleaning roller, a connecting frame and a spray head. The lifting air cylinder is vertically arranged at the top end of the portal frame, the lifting wheel frame is connected with a piston rod of the lifting air cylinder, a shaft of the cleaning roller is movably connected with the lifting wheel frame through a bearing, bristles are arranged on the outer circumferential face of the cleaning roller, a motor is arranged on the outer side of the lifting wheel frame, and a rotating shaft of the motor is coaxially connected with the shaft of the cleaning roller. The connecting frame is located on the side, away from the lifting air cylinder, of the portal frame, the spray head is located on the overturning plate, and the overturning plate is movably connected with the bottom end of the connecting frame through a hinge joint. According t