Injection molding device

1 . An injection molding device comprising:

a base to which a fixed molding die and a movable molding die are fixed, the fixed molding die having a gate opening, the movable molding die being configured to be clamped with the fixed molding die during molding, a cavity being defined by the fixed molding die and the movable molding die;

a heater included in at least one of the base and the fixed and movable molding dies;

an injection head configured to inject a molding material into the cavity via the gate opening of the fixed molding die, the molding material containing a thermosetting material and a polymerization initiator that initiates a polymerization reaction of the thermosetting material; the injection head including:

a nozzle having a nozzle opening, the molding material being injected into the cavity from the nozzle via the nozzle opening and the gate opening of the fixed molding die; and

an injection amount adjustment mechanism configured with an injection cylinder, a plunger, and a first motor, the injection amount adjustment mechanism being configured to adjust an injection amount of the molding material from the nozzle;

a second motor configured to move the injection head relative to the fixed molding die mounted on the base;

a contact pressure detector configured to detect a contact pressure between the nozzle and the fixed molding die by measuring a torque of the second motor;

a memory configured to store a program; and

a processor configured to execute the program so as to:

cause the heater to heat the at least one of the base and the fixed and movable molding dies;

cause, while heating by the heater, the second motor to move the injection head to the fixed molding die such that the gate opening of the fixed molding die is aligned with the nozzle opening;

cause, while heating by the heater, the contact pressure detector to detect a contact pressure value while aligning between the gate opening of the fixed molding die and the nozzle opening;

determine, while heating by the heater, whether the contact pressure value is equal to or more than a first predetermined value;

control, while heating by the heater, the injection amount adjustment mechanism to inject the molding material into the cavity when the processor determines that the contact pressure value is equal to or more than the first predetermined value;

control, while heating by the heater, the injection amount adjustment mechanism to stop injecting the molding material into the cavity after the molding material is injected into the cavity;

cause, while heating by the heater, the second motor to move the injection head away from the fixed molding die after a first predetermined time has elapsed from the stop of injecting the molding material; and

cause the heater to stop heating the at least one of the base and the fixed and movable molding dies after a second predetermined time has elapsed from a state in which the injection head has moved away from the fixed molding die.

2 . The injection molding device according to claim 1 , wherein

the processor is further configured to control, while heating by the heater, the injection amount adjustment mechanism not to inject the molding material into the cavity when the processor determines that the contact pressure value is less than the first predetermined value.

3 . The injection molding device according to claim 1 , wherein

the processor is further configured to:

control the second motor to move the injection head to the fixed molding die at a first speed such that the gate opening of the fixed molding die is aligned with the nozzle opening; and

control the second motor to move the injection head away from the fixed molding die at a second speed after the first predetermined time has elapsed from the stop of injecting the molding material, and

the second speed is higher than the first speed.

4 . The injection molding device according to claim 1 , further comprising:

a third motor configured to clamp the movable molding die with the fixed molding die, wherein

after the second motor moves the injection head away from the fixed molding die, the processor is further configured to control the third motor to move the movable molding die from the fixed molding die at a third speed of equal to or less than 5 mm per second.

5 . The injection molding device according to claim 1 , wherein

the injection head includes a flow path through which the molding material flows along a first direction,

the flow path includes;

a first flow path extending along the first direction; and

a second flow path extending in a second direction intersecting the first direction,

the injection amount adjustment mechanism further includes a shutoff pin that moves in the first flow path along the first direction, and

the plunger of the injection amount adjustment mechanism moves in the second flow path along the second direction.

6 . The injection molding device according to claim 1 , wherein

the injection amount adjustment mechanism includes a shutoff pin that moves along a direction in which the molding material flows inside a flow path through which the molding material flows, and

an end portion of the shutoff pin on a side of the nozzle opening is a protruding shape without a flat surface.