Control device of injection molding machine, injection molding machine, and method of controlling injection molding machine

1 . A control device of an injection molding machine including an injection member that presses a molding material and an injection drive source that moves the injection member, the control device comprising:

an injection control unit that controls, in a holding pressure process of controlling a pressure acting on the molding material from the injection member, the injection drive source based on a set value of the pressure and on an actual value of the pressure,

wherein the holding pressure process includes a first process and a second process subsequent to the first process, and

in the first process, the injection control unit replaces, for a control calculation, a set value of a pressure in the first process with a modified value obtained by subtracting a correction amount that increases over time from zero during the first process from the set value of the pressure in the first process so that an actual value of a pressure in the first process gradually decreases toward a set value of a pressure in the second process, or, replaces, for a control calculation, the actual value of the pressure in the first process with a modified value obtained by adding a correction amount that increases over time from zero during the first process to the actual value of the pressure in the first process so that the actual value of the pressure in the first process gradually decreases toward the set value of the pressure in the second process.

2 . A control device of an injection molding machine including an injection member that presses a molding material and an injection drive source that moves the injection member, the control device comprising:

an injection control unit that controls, in a holding pressure process of controlling a pressure acting on the molding material from the injection member, the injection drive source based on a current command value or a torque command value of the injection drive source and on a current actual value or a torque actual value of the injection drive source,

wherein the holding pressure process includes a first process and a second process subsequent to the first process, and

in the first process, the injection control unit replaces, for a control calculation, a current command value or a torque command value in the first process with a modified value obtained by subtracting a correction amount that increases over time from zero during the first process from the current command value in the first process or from the torque command value in the first process so that an actual value of a pressure in the first process gradually decreases toward a set value of a pressure in the second process, or replaces, for a control calculation, a current actual value or a torque actual value in the first process with a modified value obtained by adding a correction amount that increases over time from zero during the first process to the current actual value in the first process or to the torque actual value in the first process so that the actual value of the pressure in the first process gradually decreases toward the set value of the pressure in the second process.

3 . The control device of an injection molding machine according to claim 1 , further comprising:

a display control unit that displays a setting screen used for setting a decrease in the actual value of the pressure in the first process toward the set value of the pressure in the second process on a display device.

4 . An injection molding machine comprising:

the control device according to claim 1 ;

the injection member; and

the injection drive source.

5 . An injection molding machine comprising:

the control device according to claim 2 ;

the injection member; and

the injection drive source.

6 . A method of controlling an injection molding machine including an injection member that presses a molding material and an injection drive source that moves the injection member, the method comprising:

an injection control process of controlling, in a holding pressure process of controlling a pressure acting on the molding material from the injection member, the injection drive source based on a set value of the pressure and on an actual value of the pressure,

wherein the holding pressure process includes a first process and a second process subsequent to the first process, and

in the first process, the injection control process includes a process of replacing, for a control calculation, a set value of a pressure in the first process with a modified value obtained by subtracting a correction amount that increases over time from zero during the first process from the set value of the pressure in the first process so that an actual value of a pressure in the first process gradually decreases toward a set value of a pressure in the second process, or a process of replacing, for a control calculation, the actual value of the pressure in the first process with a modified value obtained by adding a correction amount that increases over time from zero during the first process to the actual value of the pressure in the first process so that the actual value of the pressure in the first process gradually decreases toward the set value of the pressure in the second process.

7 . A method of controlling an injection molding machine including an injection member that presses a molding material and an injection drive source that moves the injection member, the method comprising:

an injection control process of controlling, in a holding pressure process of controlling a pressure acting on the molding material from the injection member, the injection drive source based on a current command value or a torque command value of the injection drive source and on a current actual value or a torque actual value of the injection drive source,

wherein the holding pressure process includes a first process and a second process subsequent to the first process, and

in the first process, the injection control process includes a process of replacing, for a control calculation, a current command value or a torque command value in the first process with a modified value obtained by subtracting a correction amount that increases over time from zero during the first process from the current command value in the first process or from the torque command value in the first process so that an actual value of a pressure in the first process gradually decreases toward a set value of a pressure in the second process, or a process of using replacing, for a control calculation, the current actual value or a torque actual value in the first process with a modified value obtained by adding a correction amount that increases over time from zero during the first process to the current actual value in the first process or to the torque actual value in the first process so that the actual value of the pressure in the first process gradually decreases toward the set value of the pressure in the second process.

8 . The method of controlling an injection molding machine according to claim 6 , further comprising:

a display control process of displaying a setting screen used for setting a decrease in the actual value of the pressure in the first process toward the set value of the pressure in the second process on a display device.