Control device of injection molding machine, injection molding machine, and method of controlling injection molding machine
A technique for managing a shear heating value of a molding material is provided. A control device of an injection molding machine individually controls outputs of a plurality of heating units for a plurality of zones, respectively, into which a cylinder is divided in a flow direction of a molding material. The control device acquires the output of the heating unit provided in a predetermined zone both in a steady state in which an operation of a screw provided inside the cylinder is stopped and at a time of molding at which the operation of the screw is performed, and calculates a difference in output of the heating unit provided in the predetermined zone between at a time of molding and in the steady state.
1 . A control device of an injection molding machine, which individually controls outputs of a plurality of heating units based on a temperature measured by a temperature measurer for a plurality of zones, respectively, into which a cylinder is divided in a flow direction of a molding material, the control device comprising:
a processor configured to
acquire a first output of a heating unit provided in a predetermined zone, among the plurality of heating units, in a steady state when a screw provided inside the cylinder is stopped,
acquire a second output of the heating unit at a time of molding when the screw is operated,
calculate a difference in the first output and the second output,
raise a set temperature of a zone upstream of the predetermined zone in the flow direction, in an initial stage of a continuous operation in which the injection molding machine manufactures a molding product repeatedly, when the difference indicates that the second output is larger than the first output by more than a predetermined condition, the upstream zone closer to a feed port of the cylinder than the predetermined zone, and
control an output of a heating unit provided in the zone upstream of the predetermined zone based on the set temperature during subsequent stages of the continuous operation,
wherein the processor is configured to increase an amount by which the set temperature of the upstream zone is raised as the difference increases.
2 . The control device of an injection molding machine according to claim 1 ,
wherein, in a case where the difference indicates that the second output is larger than the first output by more than the predetermined condition, a set temperature of the zone closest to the predetermined zone among the zones upstream of the predetermined zone in the flow direction is raised.
3 . The control device of an injection molding machine according to claim 2 ,
wherein, in a case where the difference indicates that the second output is larger than the first output by more than the predetermined condition even if the set temperature of the zone closest to the predetermined zone is raised to an upper limit, a set temperature of the zone second closest to the predetermined zone is raised.
4 . The control device of an injection molding machine according to claim 1 ,
wherein the control device performs control to notify of an alarm in a case where the difference indicates that the second output is larger than the first output by more than the predetermined condition.
5 . The control device of an injection molding machine according to claim 1 ,
wherein the processor is configured to maintain the set temperature during subsequent stages of the continuous operation.
6 . An injection molding machine comprising:
the control device according to claim 1 ;
the cylinder; and
the heating unit.
7 . A method of controlling an injection molding machine, in which outputs of a plurality of heating units for a plurality of zones, respectively, into which a cylinder is divided in a flow direction of a molding material are individually controlled based on a temperature measured by a temperature measurer, the method comprising:
a process of acquiring a first output of a heating unit provided in a predetermined zone, among the plurality of heating units, in a steady state when a screw provided inside the cylinder is stopped;
a process of acquiring a second output of the heating unit at a time of molding when the screw is operated;
a process of calculating a difference in the first output and the second output;
a process of raising a set temperature of a zone upstream of the predetermined zone in the flow direction, in an initial stage of a continuous operation in which the injection molding machine manufactures a molding product repeatedly, when the difference indicates that the second output is larger than the first output by more than a predetermined condition, the upstream zone closer to a feed port of the cylinder than the predetermined zone; and
a process of controlling an output of a heating unit provided in the zone upstream of the predetermined zone based on the set temperature during subsequent stages of the continuous operation,
wherein an amount by which the set temperature of the upstream zone is raised increases as the difference increases.