Tool for disassembling sealing gasket in engine

The invention belongs to the technical field of sealing gasket dismounting, and particularly relates to an engine internal sealing gasket dismounting tool which comprises a mandrel, a screw rod, a fixed screw sleeve, an expansion sleeve and a hexagon nut. A conical head with the diameter gradually increased is arranged at the bottom end of the mandrel, and the outer diameter of the largest position of the conical head is equal to or smaller than the inner diameter of a sealing gasket to be detached. A guide part integrally extends from the bottom of the expansion sleeve; a plurality of expansion parts are uniformly distributed on the circumference of the bottom wall of the guide part; the screw rod is arranged in an inner hole of the expansion sleeve in a sliding manner; the mandrel is tightly attached to the inner wall of the guide part, penetrates into an inner hole of the expansion sleeve and is in threaded connection with the screw rod; the fixed screw sleeve is in threaded connection with the bearing sea