Multi-stage tablet core retention prevention mechanism for sun door of coating machine

The invention discloses a multi-stage tablet core retention prevention mechanism for a sun door of a coating machine, and relates to the technical field of coating machines. The coating machine door body is provided with a discharging port, the material door body is installed on the front side of the coating machine door body, the roller is rotatably installed in the coating machine door body, a roller opening, close to one side of the discharging port, of the roller is provided with an inner conical surface, and a pot opening flange matched with the outer end of the inner conical surface in caliber is correspondingly arranged on the inner side of the material door body. A guide frame is fixedly connected to one side of the material door body, an extending block is slidably connected into the guide frame, and a check block is fixedly connected to one side of the extending block. The tablet core can be directly lifted back into the roller through the check block on the material door body, certain thrust is gen