Positioning structure and method for improving dimensional precision of sand core in sand-lined metal mold production

According to the positioning structure and method for improving the dimensional precision of the iron mold sand-lined production casting, the positioning structure comprises a sand core body and a core base, the two ends of the sand core body are each provided with a core head, the two core heads are fixed in a core base cavity, and a fit clearance is formed between each core head and the core base cavity; a circle of sand collecting groove is formed in the edge of the bottom of each core seat, a plurality of abrasive belt protrusions are arranged on the inner side face of each core seat or the outer side face of each core head, and the thickness of each abrasive belt protrusion is larger than the fit clearance. The invention further provides a method for improving the size precision of the sand core by using the positioning structure. Through the abrasive belt protrusions on the core seat or the core head, interference fit is formed between the core head and the core seat, redundant sand can be rubbed off an