摘要 |
The state in which a mold is filled with molten resin is held constant at all times by holding constant the temperature of the mold at the start of injection of the resin, thus suppressing a fluctuation in the weight and dimensions of the molded articles. Cooling channel are arranged around a cavity of an injection mold filled with a heated molten resin. Use is made of a response model of a variation in mold temperature in the injection mold. The variation in mold temperature, coolant temperature and temperature of the filling molten resin in a molding cycle are measured, and a parameter (time constant) of the response model is decided using these measured values. If the molding cycle is changed or the measured mold temperature develops a difference with respect to a standard mold temperature, a target value of coolant temperature is calculated using the response model in such a manner that the mold temperature at the start of injection will be held constant at all times, and control of the coolant temperature is carried out using this target coolant temperature.
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