| 摘要 |
PURPOSE:To cause the temperature rise in each heating zone of an extrusion machine to be simultaneously completed at desired time by a method in which each electric heater is specified by the function approximate to temperature rise characteristics, and the temperature-rise time of each electric heater is calculated by a computer from the calculation of the deviation between the control point-temperature raised on the basis of said function and a set temperature. CONSTITUTION:The heating conditions of electric heaters 13a, 13b, 13c... are detected by the thermocouples 17 fitted to a cylinder 10, and are sent to a computer 16 through PID thermostat 14a, whereby the temperature-rise characteristics the temperature at control point and the deviation temperature, etc., of each electric heater 13a... are calculated. The temperature-rise, characteristics each electric heater in each heating zone of an extrusion machine are represented by the approximate function of y(t)= K[1-exp{-(t-L)/T}]. Here, K is process gain constant, L is equivalent dead time constant, and T is equivalent time constant. The constant of the temperature-rise characteristics of each electric heater in each heating zone in said extrusion machine is calculated by the data of the temperature-rise curve in each zone. |
