CONTROL METHOD AND DEVICE FOR MOLD TEMPERATURE

PURPOSE:To control precisely and accurately the mold temperature by means of a heating medium by switching the heating medium fed from a pump in the direction of returning the same to a tank when the heat amount computed by a second operator reaches a required heat amount computed by a first operator. CONSTITUTION:Temperature T1 of a heating medium flowing into a mold 1 and temperature T2 of a heating medium flowing out of the mold 1 are measured by temperature measuring devices 20 and 21 and heat amount (u) applied to the mold 1 is computed by a second operator consisting of a multiplier 30 and an integrator 31. Said heat amount (u) is compared with the required heat amount U computed by a first operator 26, and while difference is in said comparison, a flip-flop circuit 33 is actuated to retain first-third electromagnetic valves 5, 6 and 14 as they are. Signals from a comparison device 32 are zero when the computed heat amount (u) reaches the required heat amount U to reset the circuit 33 and demagnetize the first-third electromagnetic valves 5, 6 and 14. Accordingly, a pump 7 and the mold 1 are shut off, and a high temperature heating medium discharged out of the pump 7 is returned to a tank 9.