PROCESSO DE MOLDACAO EM COQUILHAS A BAIXA PRESSAAO PARA A FUNDICAO DE PECAS METALICAS

The invention relates to a low-pressure chill casting process for producing metal castings, e.g. cylinder heads or engine blocks of internal combustion engines or the like, the walls of which are much thinner in some areas than in others. In this process, pressurized gas forces molten metal out of a melting crucible through a rising pipe into a mould. The mould is arranged so that the thicker wall of the casting is cast in the upper part of the mould remote from the gate and the thinner wall is cast in the lower part of the mould near the gate. The molten metal is introduced into the mould cavities that form the thinner wall at or near the lower region of the mould. The molten metal can be introduced into the mould cavities that form the thinner wall of the casting through a base runner at several gates in the lower, gate region of the mould.