Injection molding machine and fluidity measurement method

An injection molding machine, comprising:

• an injection unit comprising an injection axis that extrudes and injects a molding material;
• a measurement unit attached to the injection unit;
• a position sensor measuring a position of the injection axis;
• a pressure sensor measuring a pressure of the molding material;
• and
• a controller,
• wherein the measurement unit comprises:
• a measurement cylinder which is attached to the injection unit and through which the molding material injected by the injection unit flows;
• a die attached to the measurement cylinder and having a die hole configured to allow the molding material to flow through;
• a purge opening provided in the measurement cylinder, having a larger cross-sectional area than the die hole, and configured to allow the molding material to flow through;
• and
• a flow path switching pin selectively switching a discharge destination of the molding material to one of the die and the purge opening,
• wherein the controller is configured to, in response to measurement start being instructed, meter the molding material, advance the injection axis so that the pressure of the molding material matches a set test load, discharge the molding material from the die hole, and calculate a melt flow rate using any one of a mass of a test piece obtained by cutting the molding material discharged from the die hole every predetermined time, a distance by which the injection axis moves in a predetermined time, and a time required for the injection axis to move a predetermined distance.