Manufacturing structure of triangular combined core iron

The utility model belongs to the field of casting core manufacturing, and particularly relates to a manufacturing structure of triangular combined core iron, which is suitable for all sand cores withthe length of more than 4m. The structure includes: a housing; a core hanger I, a core hanger II, a core hanger III, a core hanger IV, a circular steel pipe I, a connecting rod I, a circular steel pipe II, a connecting rod II, a circular steel pipe III and a connecting rod III are arranged; according to the specific structure, a first round steel pipe, a second round steel pipe and a third round steel pipe are arranged in parallel in a triangular shape, the first round steel pipe and the second round steel pipe are welded through evenly-distributed first connecting rods, the second round steelpipe and the third round steel pipe are welded through evenly-distributed second connecting rods, and the third round steel pipe and the first round steel pipe are welded through a third connecting rod. The triangular structu