| 摘要 |
PURPOSE:To prevent the intrusion of a gas into the molten metal in the cavity for forming a cylinder block and to avert the generation of blowholes by decreasing stepwise the sections of a pair of runners along both bottom edges parallel with the crank axial line of said cavity from the upper stream to the down stream so that the molten metal in the cavity rises uniformly. CONSTITUTION:An apparatus for production consists of an upper mold 9, side molds 101, 102 and a lower mold 11. The cavity C for forming the cylinder block is provided to the molds 101, 102. A pair of the runners 17 along both bottom edges parallel approximately with the crank axial line of the cavity C and a pouring part 14 communicating with the upper stream end of both runners 17 are provided to the mold 11. The base 17b of each runner 17 is formed to an uphill stepwise shape and the top surfaces of both runners 17 are formed approximately horizontally to constitute the casting mold which is stepwise decreased in the sectional areas of the both runners 17. The molten metal is poured through both runners 17 and gates 19 into the cavity C by rising of a plunger 16. |
