Accurate composite positioning method for 3D printing multi-section sand core and iron core head

The invention discloses a 3D printing multi-section sand core and iron core head precise composite positioning method. The method comprises the steps that 1, a sand core segmentation technology is designed, and trapezoidal thick inner threaded holes used for connecting all sections are formed in all the sections of sand cores; 2, designing a convex iron core head, a concave iron core head and trapezoidal thick external threads of the convex iron core head and the concave iron core head which are matched with the trapezoidal thick internal threaded hole according to the trapezoidal thick internal threaded hole designed in the step 1; 3, a sand core with an internal thread is subjected to 3D printing, a convex iron core head and a concave iron core head are machined, and a chilling block is machined; step 4, assembling each section of sand core with the corresponding chilling block, the convex iron core head and the concave iron core head; step 5, coating the sand core sections assembled in the step 4 with pain