| 摘要 |
PURPOSE:To contrive to improve the productivity and dimensional accuracy of product and to prevent the defective external appearance from developing by a method wherein mold temperature is controlled by supplying hot water and cooling water alternately in the medium passage of a mold. CONSTITUTION:Just before the mold opening, the outside air is led in a medium passage 2. Just after the mold opening, the circulating loop of hot water is formed by actuating changeover valves 5 and 6 so as to communicate a valve port 5a to a valve port 5d and a valve port 6a to a valve port 6c. The hot water is kept on supplying to the medium passage 2 in order to heat a core 1 by the suction of a pump 7 in the circulating loop. The heating of the core 1 is continued during the period ranging from after the taking-out of a product through the closing of a mold to just before the finish of filling of resin. Because the temperature of hot water is set so as to keep the surface temperature of the core above the dew point, no dew condensation is developed on the core. In addition, because the surface temperature of the core at the filling of resin is enough high, the filling speed can be increased. |
