Fuzzy inference thermocontrol method for an injection molding machine

Claim 1

A thermocontrol method for an injection molding machine so as to control thermocontrolled components to maintain an object temperature corresponding to an operating status of the injection molding machine, comprising the steps of: detecting the operating status of the injection molding machine and the temperature of the thermocontrolled components thereof; calculating the deviation between the object temperature of the thermocontrolled components corresponding to the present status of the injection molding machine and the present temperature detected, and the rate of deviation change between the present deviation and the previous deviation; performing fuzzy inference to define a control value of means for heating the thermocontrolled portions or means for cooling the thermocontrolled components by inferring the status of the injection molding machine, the deviation calculated and the rate of deviation change, wherein the status of the injection molding machine, the temperature deviation, the rate of deviation change and the control value of the means for heating or the means for cooling are defined as fuzzy variables, and wherein the inference is based on rules governing a mutual relationship among membership functions and groups into which the member grades assigned to previously and optionally divided areas which correspond to respective optional values of the fuzzy variables; calculating an actual control value of the means for heating or the means for cooling based on the fuzzy inference; and controlling the temperature of the means for heating or the means for cooling with the actual control valve.