Upper carton pushing device in carton unpacking machine

The invention discloses an upper carton pushing device in a carton unpacking machine. At least one pressing mechanism for pressing the tops of cartons is arranged at the bottom of a mounting support, a carton pushing block mechanism with a carton pushing block is further arranged at the bottom of the mounting support, the carton pushing block in the carton pushing block mechanism can push the cartons to move forwards, the structure of each pressing mechanism comprises a square tube fixedly mounted at the bottom of the mounting support, mounting plates are respectively mounted on two sides of a guide track support at the bottoms of the square tubes fixedly, a plurality of roller sleeves are mounted between the mounting plates on the two sides of the guide track support, each roller sleeve sleeves a corresponding mounting shaft, two ends of each mounting shaft are respectively mounted on the mounting plates on two sides of the guide track support, each roller sleeve can rotate on the corresponding mounting shaf