MOLD APPARATUS FOR MOLDING

PURPOSE:To make the interior of a cavity air tight securely, to get rid of damage of an elastic packing and to improve the durability by fixing air-tightly a shroud shrouding the side peripheries of a cavity mold and a core mold with a gap on an upper adapter plate of the core mold, bringing the lower end with an arc face into press-contact with an elastic packing of a lower adapter plate to seal and drawing a vacuum from a vent of the upper adapter plate. CONSTITUTION:A core mold 11 is tightly fixed or formed integrally with an upper adapter plate 12 to provide a core part 11a below and a cavity mold 13 is tightly fixed or integrally formed with a lower adapter plate 15 to form a cavity 14 thereabove. A groove 15a for a packing is provided on the outside of the side periphery of the cavity mold 13 on the upper face of the lower adapter plate 15 and an elastic packing 17 is inserted therein. A shroud 18 shrouds the side peripheries of the core mold 11 and the cavity mold 14 with a gap and is air-tightly fixed on the upper adapter plate 12 and the lower end is formed in an arc-shaped face. In addition, a vent 19 is provided on the upper adapter plate 12 to communicate the space of the inner periphery of the shroud 18 and is connected with a vent pipe 20. When the upper adapter plate 12 is lowered and drawing a vacuum from the vent 19 is performed and the lower end of the shroud 18 is brought into press-contact with the elastic packing 17, elastic deformation is sufficiently performed and air-tight sealing can be effected without any damage.