Fecha de publicación: 04/01/2022 Fuente: Wipo Olive Table The invention discloses a mold loose core device for an exhaust joint in a fuel tank. The device is arranged between an upper mold and a lower mold, forms a mold cavity with the upper mold and the lower mold, and comprises a base, a drawing rod is arranged in the base in a penetrating manner, the end part of the drawing rod is fixedly connected with a conical drawing head, the periphery of the drawing head is provided with a sliding groove along the axial direction, a loose core capable of sliding in the axial direction is arranged in the sliding groove, the position, located at the bottom of the loose core, of the periphery of the drawing head is sleeved with a limiting table, the periphery of the limiting table and the periphery of the loose core are sleeved with an outer sleeve, the inner wall of the outer sleeve is attached to the peripheries of the loose core, the drawing head and the limiting table, and the mold cavity is formed among the outer sleeve, the upper mold and the lower mold. The problem that in the prior art, the demolding efficiency of a buckle-down structure is low is solved. The labor cost is reduced and the production efficiency is improved.