Core-Making Equipment

devices for the mechanized production of mold cores by filling a corebox with a core mixture and then packing the mixture.

According to the method for packing the mixture, machines are classified as extruding, squeezing, jolting, blowing, slinging, or centrifugal machines. Core-extruding machines are used for producing cores with a uniform cross section. The cores are cut to length as they leave the machine. Extrusion is used for lot and mass production of cores. In machines employing squeezing, the mixture is packed in the box by a mechanism having a pneumatic or hydraulic drive. This method is used for the lot production of small or medium-size cores in dump-type and split-type core-boxes. It is also used in producing cores of this size with individual specifications.

In jolt machines, the mixture is packed by jolting the corebox on a table either manually or with a pneumatic cylinder. After packing, the corebox is inverted and the core removed again either manually or with a pneumatic mechanism. Jolt machines are used for the lot or mass production of medium-size and large cores. Core-blowing machines make use of the kinetic energy of the sand-air stream for filling the corebox and packing the mixture. Machines of this type permit the production of cores of any shape, and they greatly accelerate the forming process.

In core-making equipment employing centrifugal force, the packing and subsequent hardening of the mixture occur in a box heated to 220°-250°C by the action of centrifugal forces arising from the box’s rotation. This type of equipment is used for the production of shell cores with simple shapes in lot and mass production. Sand-slinging equipment is used in the lot and mass production of medium-size and large cores. Core-blowing machines, which permit the greatest mechanization in the lot and mass production of cores, are the most common in industry.