PURPOSE: To obtain easily and in a short period a casting plan with which castings having no shrinkage cavity are manufactured by giving necessary data on the basis of the analytical model set with the shape of the casting and casting mold, making the temp. gradient distribution chart of the casting by numerical analysis and evaluating the analytical model from said chart.
CONSTITUTION: An element breakdown chart is made by a mesh generator on the basis of each basic shape of the casting 1 and casting mold 2. Density, specific heat and heat conductivity are given to each element, latent heat and the relation between temp. and solid phase rate are given to the casting and further the heat conductivity determined by boundary conditions is given to the respective boundary parts of (atmosphere and casting), (casting mold and casting) and (atmosphere and casting) then a numerical analysis is executed. The temp. distribution chart at the solid phase rate above the threshold solid phase rate for the generation of the shrinkage cavity is made from the results thereof and the part where the shrinkage cavity is liable to arise is predicted therefrom. For example, the part where the temp. gradient is low, i.e., the lower part of a flange and the opposite surface of a chiller 3 are predicted to have an easy tendency to the shrinkage cavity.
SUZUKI TOSHIO
NAKAGAWA TOMOKAZU
YABU TADASHI
SAKAMOTO TOSHIMASA
YOSHIDA CHISATO
