Injection molding apparatus and injection molding method

An injection molding apparatus comprising:

• an injection-molding mold including a fixed mold and a movable mold, the fixed mold having a gate opening into which a molding material flows, the movable mold having a cavity and being configured to be separated from the fixed mold during mold opening;
• a hot runner including a nozzle having a channel that guides the molding material to the gate opening, and a heater, the hot runner being disposed in the fixed mold;
• and
• a control unit that controls a temperature of the heater to adjust a temperature of the hot runner, wherein
• the control unit
• controls the temperature of the heater to a first temperature when the molding material is injected from the hot runner to the cavity, and
• after the injection of the molding material is completed, controls the temperature of the heater to a second temperature that is higher than the first temperature, and
• a gap between the nozzle and the gate opening when the temperature of the heater is controlled to the second temperature is narrower than the gap when the temperature of the heater is controlled to the first temperature.