METHOD FOR CONTROLLING THE TEMPERATURE OF A PLASTIC MOLD

摘要

A method for controlling the temperature of injection molding machines usi ng cross-linking polymers and molding die units using plastics. Each unit is equipped with at least one cooling channel for circulating a temperature controlling medium therethrough. The temperature of the exhausted medium is compared to a desired value and t he circulation of the medium is adjusted accordingly. The method includes the steps of calculating the heat dissipation within a cycle and presetting the desired heat dissipation, prior to the start of temperature control. The temperature of the exhausted medium and the feed medium are continuously measured. The heat content WRG of the unit is determined once the unit reaches thermal equilibrium. The value WRG is store d in a subsequent cycle as a desired value based on the difference between the temperature of the exhausted medium and the feed medium during a reference cycle. The desir ed value is compared with the instantaneous actual value measured during all subseque nt cycles. A correction value is determined based on the deviation of the heat content fr om the reference cycle. The temperature control impulses trigger at point Z1 and terminate at Z2 at the latest. Events Z1 and Z2 are preset by signals from the unit sequence controller.