L_die = L_part·(1+s)+wear;收缩波动+磨损的公差预算
L_die = L_part·(1+s) + wear。把零件尺寸换算成型腔尺寸,并做收缩波动 + 磨损的公差预算——判断该尺寸能否靠压铸直接保证。