▎ 摘　　要

NOVELTY - Casting ball iron large loader back seat by V method comprises (i) making the upper part and the lower part, and make two sets of corresponding matching tooling; (ii)heating the film to high brightness; (iii) spray painting on the film and drying; (iv) adding special sand box on the model covered with film; (v) adding top of the sand box Scrape the surface flat; (vi) releasing vacuum of the vacuumbox, release the adsorption force on the film, and then lift the mold from the top box to complete the casting; (vii) closing and fastening the upper and lower mold cavities, where the upper and lower sand boxes are respectively connected to the vacuum system; (viii)using a closed pouring system, the temperature of the molten metal poured is 1410-1450degrees Celsius,; and (ix) pouring, the vacuum of the vacuum frame of the sand box still maintains 0.035MP-0.045MP, where the vacuum is released after 12-16 minutes, and the sand is released after 1 hour. USE - The method is useful for vasting ball iron large loader back seat by V method. ADVANTAGE - The method solves the problem that the existing castings are prone to air hole defects by opening air holes on the upper and lower patterns, and adopting a closed pouring system and heat treatment operations. DETAILED DESCRIPTION - Casting ball iron large loader back seat by V method comprises (i) making the upper part and the lower part, and make two sets of corresponding matching tooling according to the upper part and the lower part according to the shape of the upper parting and the lower parting of the casting and open ting the upper part and the lower part respectively several ventilation holes; (ii)heating the film to high brightness, press the film at the corner with a flat foam board to make it close to the surface of the model and then opening the vacuum valve for vacuuming and vacuum lamination; (iii) spray painting on the film and drying; (iv) adding special sand box on the model covered with film, add the modeling sand with a particle size of 80-140 mesh into the sand box, and then vibrating while adding the modeling sand; (v) adding top of the sand box Scrape the surface flat, placing on the sealing film, and connecting the sand box to the vacuum system to remove the air in the sand box to harden the mold; (vi) releasing vacuum of the vacuum box, release the adsorption force on the film, and then lift the mold from the top box to complete the casting; (vii) closing and fastening the upper and lower mold cavities, where the upper and lower sand boxes are respectively connected to the vacuum system; (viii)using a closed pouring system, the temperature of the molten metal poured is 1410-1450degrees Celsius, and the vacuum frame of the sand box during the pouring process maintains a vacuum of 0.032-0.052 MP, where poured molten metal is composed 3.9-4.5% carbon, 1.2-2.2%, silicon 0.15-0.25% manganese, 0.022-0.026% sulfur, 0.045-0.065% phosphorus, 0.04-0.06% magnesium, 0.02-0.04% rare earth and Iron (remaining amount); and (ix) pouring, the vacuum of the vacuum frame of the sand box still maintains 0.035MP-0.045MP, where the vacuum is released after 12-16 minutes, and the sand is released after 1 hour.