Method for using metal type sand-covering technique to manufacture brake drum

The invention relates to a method of manufacturing a brake drum by utilizing a metal-typed sand covering technique, comprising a die joint is determined by the maximum diameter position of the brake drum, a lower joint is determined by a large mouth part and an upper joint is determined by a small mouth part; an internal model and an external model are respectively arranged in order to ensure the internal profile dimension and the external profile dimension of the brake drum; an internal sand box and an external sand box are respectively arranged in order to manufacture the lower joint and the upper joint of the brake drum; after the internal model and the internal sand box, the external model and the external sand box are assembled according to prearranged clearances, the internal sand box and the external sand box are covered with sands through a sand injection hole; metal liquid is poured after the internal sand box and the external sand box with sand cover are tightly locked. The invention has the advantages of improving working environment, more precise dimension of the castings, better surface quality, higher yield, lower cost and higher production efficiency.