Lower case sealing mechanism of case unpacking machine

The invention discloses a lower case sealing mechanism of a case unpacking machine. A lower movement of the lower case sealing mechanism is fixedly arranged on a rack; a limiting upper frame can be movably arranged on the rack vertically; a pair of transfer mechanisms can be arranged on the rack in a mode of being close to each other or away from each other, and can be positioned at the two sidesof the lower movement; an inlet side of the lower movement is provided with a turnover mechanism for turning over a lower cover of a carton; the turnover mechanism comprises a pair of front and rear longitudinal abut-against parts which abut against front and rear lower covers of the carton to turn over during rotation, and a pair of left and right transverse abut-against parts which abut againstleft and right lower covers of the carton to turn over during rotation; the limiting upper frame and an upper retaining frame of a storage mechanism are synchronously regulated in upper and lower positions through a first elec