Injection molding device

An injection molding device, comprising:

• an injection device including a cylinder, a screw, and a nozzle provided at a front end of the cylinder, for discharging molten resin as the screw advances;
• a mold including a molded product cavity, and a resin channel between the molded product cavity and a portion abutting the nozzle;
• a channel pressure measuring device for acquiring channel pressure data in the resin channel;
• a viscosity estimation unit configured to estimate viscosity of the molten resin flowing through the resin channel in the mold;
• a determination unit configured to determine presence/absence of clogging of a gate of the resin channel, taking into consideration the viscosity estimated by the viscosity estimation unit, based on features of the channel pressure data;
• a screw pressure measuring device that acquires screw pressure data regarding pressure the screw receives from molten resin in the cylinder;
• and
• a control device configured to control the injection device, the control device executing a molding cycle including
• an injection process of injecting molten resin from the nozzle into the mold by performing speed control of the screw, and
• a pressure-holding process of applying a holding pressure to the molten resin in the molded product cavity by performing pressure control of pressure applied to the screw, performed following the injection process, wherein the viscosity estimation unit configured to estimate the viscosity using time from start time of the injection process to a pressure peak time of the channel pressure data in the injection process as one of components representing the viscosity.