Manufacturing method of core for casting engine exhaust manifold

The invention relates to a manufacturing method of a core for casting an engine exhaust manifold, comprising the following steps of: 1, manufacturing a resin assembly mould by a photo curing fast-shaping technique; 2, manufacturing reinforcing iron wires in shape of spatial spiral curve same as the core; 3, filling sands in the mould and putting into the reinforcing iron wires manufactured in the step 2; 4, scraping resin sands along a mould sectional surface by a scraper to make the resin sands protrude a little, and then folding the mould to press tightly; 5, opening the mould to take out the core and carrying out the proper post-treatment on the core after the resin sands are solidified. In the invention, the complex core resin assembly mould manufactured by the fast-shaping method has light weight and good strength, and the surface roughness thereof can also achieve Ra=3.2mum; therefore, in the premise of guaranteeing the quality of the manufactured core, the manufacturing cost and the manufacturing period of the mould can be greatly reduced, and the more complex shape of the manufacturing assembly is, the more remarkable advantages of the method are.