Injection molding apparatus

An injection molding apparatus comprising:

• a support that supports a molding die including an upper die and a lower die;
• an injection head configured to inject a molding material toward a cavity defined by the upper die and the lower die, the injection head including:
• a flat screw having a groove forming surface in which a groove is formed;
• a barrel having a flat screw facing surface facing the groove forming surface and having a communication hole into which the molding material flows;
• and
• a heater configured to heat a source material supplied to a space between the groove forming surface and the flat screw facing surface;
• a die clamping motor configured to drive a die clamper to move the upper die and the lower die along a vertical direction to clamp and release the upper and lower dies relative to each other;
• a memory configured to store a program;
• and
• a processor configured to execute the program so as to:
• control the injection head to plasticize at least part of the source material due to rotation of the flat screw and heat from the heater to produce the molding material and deliver the molding material into the communication hole;
• control the die clamping motor so that a value of torque produced thereby becomes a first torque value and press the upper die against the lower die, thereafter lower the value of torque from the first torque value to a second torque value and press the upper die against the lower die, and further raise the value of torque from the second torque value to a third torque value and press the upper die against the lower die;
• and
• cause the injection head to inject the molding material into the cavity via the communication hole after the upper die is pressed against the lower die with the third torque value,
• wherein the injection head, the upper die, and the lower die are arranged sequentially from above in the vertical direction in a state in which the molding die is supported by the support.