Limiting structure for film roll of packaging machine

The utility model discloses a limiting structure for a film roll of a packaging machine, which comprises a film roll mounting structure and a limiting structure, and the limiting structure is arranged inside the film roll mounting structure; the limiting structure comprises a plurality of driving bins formed in the film roll mounting structure, electromagnets are fixedly connected to the interiors of the driving bins, a control switch is fixedly connected to the surface of the film roll mounting structure, the control switch is electrically connected with the electromagnets, and strong magnetic plates are arranged in the driving bins in a sleeving and sliding mode. The strong magnetic plate and the electromagnet are attached, and the same poles are arranged oppositely. The limiting plates are pushed to be attached to the two sides of the film roll according to the principle that like poles of magnetic force repel each other, so that the two sides of the film roll are positioned, and compared with an existing