Unwinding mechanism with brake band tensioning function

The utility model discloses an unwinding mechanism with a brake band tensioning function, which comprises a feeding seat, an unwinding shaft and a swing rod component, one end of the unwinding shaft is vertically inserted into the feeding seat, a raised square block is arranged at the center of the unwinding shaft, a brake wheel is arranged in the feeding seat, and the center of the brake wheel is fixedly clamped with the square block. A belt clamping base and a deep groove ball bearing which are assembled below the brake wheel and integrally connected are further arranged in the discharging base, the brake wheel is further sleeved with a brake band, the bottom of the brake band is connected with the belt clamping base, and a brake shaft making contact with the brake band is inserted into the belt clamping base. One end of the swing arm is connected with a tensioning shaft inserted into the discharging base, the other end of the swing arm is connected with a swing rod roller, the tensioning shaft is connected