Internal-closed ring cast part and preparation method thereof

The invention discloses an internal-closed ring cast part and a preparation method thereof. The method comprises the working procedures: (a) enabling a metal tube to be closed end to end, so as to form a closed ring (1), and forming a plurality of locating holes (2) in the closed ring (1), so as to prepare a closed ring blank; (b) placing the closed ring blank into an upper die (4) with a plurality of through holes, enabling locating members (5) to penetrate through the through holes and extend into the corresponding locating holes (2), so as to fix the closed ring blank; (c) closing a lower die (6) and the upper die (4), and carrying out die casting. The method has the advantages that the steps are simple, complicated internal-closed ring cast parts can be prepared, meanwhile, the qualified rate of products is high, and the production cost is greatly reduced.