Upper cover sand core and preparation method thereof

The invention discloses an upper cover sand core and a preparation method thereof, relates to the technical field of casting, solves the problems of high riser removal difficulty and poor removal effect in a casting process using the upper cover sand core, and saves the cost, and adopts the specific scheme that the upper cover sand core comprises a riser neck arranged on the upper cover sand core, and the riser neck penetrates through the upper cover sand core; the riser neck is composed of a first riser neck unit and a second riser neck unit which are arranged up and down, the first riser neck unit and the second riser neck unit are each of a conical hole structure, and the small opening end of the first riser neck unit and the small opening end of the second riser neck unit are in butt joint and communicated to form a riser stress groove structure. A fiber net with the width smaller than the diameter of the small-opening end is fixedly installed at the butt joint position of the small-opening end. 本发明公开了一种上