Rapidly replaceable loose piece

The utility model discloses a quickly replaceable loose piece, which comprises a device main body, an upper die is arranged at the upper end of the device main body, a lower die is arranged at the lower end of the device main body, a sliding chute is arranged in the lower die, a fixed seat is connected to the outer side wall of the lower die, third bolts are symmetrically arranged in the fixed seat, and the third bolts are connected with the sliding chute. Threaded sleeves are fixedly installed on the outer side wall of the lower die and symmetrically arranged at the two ends of a sliding groove, third bolts are in threaded connection with the interiors of the threaded sleeves, the device body is formed by combining the upper die and the lower die through the sliding groove formed in the device body, and when a loose piece needs to be replaced, the upper die block is lifted, and the lower die block is inserted into the sliding groove. And the first bolt and the second bolt are taken down, so that the fixing s