Temperature control method and temperature control device

A temperature control device that heats an injection molding heating target with a heater, detects the temperature of the heating target, and controls electrical power supplied to the heater by means of a feedback control system including PID control such that a detected, actually measured temperature Ta reaches a preset target temperature Ts, the device comprising:

• a reference energization rate calculation unit that creates, by means of the PID control, a first energization rate y1 based on a first temperature difference e1 between the actually measured temperature Ta and the target temperature Ts;
• an interpolation calculation unit that creates a second energization rate y2 based on a second temperature difference e2 between an ambient temperature Te of an environment in which the heating target is disposed and the target temperature Ts;
• a comparison calculation unit that obtains a corrected energization rate y by a comparison of the first energization rate y1 and the second energization rate y2;
• and
• an operation amount processing unit that controls the electrical power supplied to the heater using the corrected energization rate y obtained by the comparison calculation unit,
• wherein the comparison calculation unit sets the corrected energization rate y to one of the following first, second, and third conditions on the basis of the comparison;
• y=y1;
• first condition:
• y=y2−α1;
• and second condition:
• y=y2+β1, third condition:
• where α1 and β1 are respectively predetermined management allowable values that are set in advance and consist of positive numbers, and
• wherein the comparison is performed such that the corrected energization rate y:
• is set to the first condition in the case of y2−α1≤y1≤y2+β1;
• is set to the second condition in the case of y1<y2−α1;
• and
• is set to the third condition in the case of y2+β1<y1.