Injection molding control device and injection molding machine

Abstract

An injection molding control device according to one embodiment of the present disclosure is an injection molding control device for controlling heaters in an injection molding machine having a barrel, one or more heaters for heating the barrel, and one or more detectors for detecting state values, comprising: a dataset storage unit for storing a plurality of datasets each including one or more limit setting values that limit the maximum output of the heaters; an information acquisition unit for acquiring at least one piece of operation information, being information indicating the state of the injection molding machine or information input by a user; a dataset selection unit for selecting one dataset from among the plurality of datasets on the basis of the one or more pieces of operation information acquired by the information acquisition unit; and a heater control unit for limiting the output of the heaters in accordance with the dataset selected by the dataset selection unit.

Description

Injection molding control device and injection molding machine

[0001] The present invention relates to an injection molding control device and an injection molding machine.

[0002] Injection molding machines are widely used, in which a screw is disposed inside a barrel (cylinder), resin is transported through the barrel by rotation of the screw, melted, and then the molten resin is injected into a mold to form a resin molded body. In injection molding machines, the barrel is usually heated to a temperature suitable for the process using a heater.

[0003] Heaters used in injection molding machines have a limited lifespan, and as the heater temperature increases, the heater lifespan tends to shorten. For this reason, it has been proposed to limit the heater output so that the heater temperature does not exceed a set temperature (see, for example, Patent Document 1).

[0004] JP 2012-236349 A

[0005] Installing a sensor to detect the heater temperature to ensure the heater's lifespan increases costs. Furthermore, simply setting a maximum heater temperature does not allow optimal control under various conditions. For example, the degree of heater wear and the quality of injection molding can vary depending on whether or not insulation is used to keep the barrel warm. Therefore, a technology that can appropriately control the heater under various conditions is desired.

[0006] An injection molding control device according to one aspect of the present disclosure is an injection molding control device that controls the heater in an injection molding machine having a barrel, one or more heaters that heat the barrel, and one or more detectors that detect status values, and includes: a dataset memory unit that stores multiple datasets each including one or more limit setting values ​​that limit the maximum output of the heater; an information acquisition unit that acquires operating information such as information indicating the status of the injection molding machine and information input by a user; a dataset selection unit that selects one of the multiple datasets based on the one or more pieces of operating information acquired by the information acquisition unit; and a heater control unit that limits the output of the heater in accordance with the dataset selected by the dataset selection unit.

[0007] FIG. 1 is a schematic diagram showing a configuration of an injection molding machine according to a first embodiment of the present disclosure.

[0008]

[0023] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of an injection molding machine 1 according to one embodiment of the present disclosure. The injection molding machine 1 includes a molding machine main body 10 and an injection molding control device 20 which is itself an embodiment of the present disclosure.

[0009] The molding machine main body 10 comprises a barrel (cylinder) 11, one or more screws 12 provided inside the barrel 11, a nozzle 13 provided at the tip of the barrel 11, a supply feeder 14 provided at the base end of the barrel 11, one or more heaters 15 for heating the barrel 11 and the nozzle 13, one or more temperature sensors 16 for detecting the temperature of the barrel 11 and the nozzle 13 as a status value indicating the state of the injection molding machine 1, one or more removable heat insulating materials 17 covering the barrel 11, and one or more installation detectors 18 for detecting whether or not the heat insulating material 17 is installed as another status value indicating a state different from the temperature of the injection molding machine 1.

[0010] The barrel 11 houses the screw 12 and has a cavity 111 that serves as a resin flow path. The barrel 11 has a main supply port 112 through which the main resin material is supplied from a supply feeder 14. The barrel 11 may have additional supply ports (not shown) for supplying auxiliary materials, additives, etc. The screw 12 is driven to rotate by a motor 121 and pressurizes the resin supplied to the cavity 111 while moving it to a nozzle 13. The nozzle 13 defines a flow path for injecting the resin into a mold (not shown). The supply feeder 14 supplies pelletized resin to the cavity 111 through the main supply port 112. The heaters 15 may be formed by resistance heating elements. Temperature sensors 16 are preferably provided corresponding to each heater 15 to individually control the output of the heaters 15. A heat insulating material 17 may be used to suppress heat dissipation from the barrel 11 to the atmosphere. The heat insulating material 17 may be divided into multiple pieces. The attachment detector 18 individually detects the attachment of the heat insulating material 17. The attachment detector 18 may be formed of, for example, a limit switch or the like.

[0011] The injection molding control device 20 controls the screw 12, the supply feeder 14, the heater 15, etc. of the molding machine main body 10. The injection molding control device 20 has a processor, a memory, etc., and can be configured by one or more computer devices that execute appropriate control programs.

[0012] The injection molding control device 20 has a data set storage unit 21, an information acquisition unit 22, a data set selection unit 23, a heater control unit 24, a data set synthesis unit 25, and a data set creation unit 26. In addition, the injection molding control device 20 is connected to an input device 27 that allows a user to input data.

[0013] The dataset storage unit 21 stores a plurality of datasets, each including one or more limit setting values ​​that limit the maximum output of the heater 15 during operation. Examples of limit setting values ​​include an output upper limit, an output rate (ratio to the rated value) upper limit, a current upper limit, a resistance upper limit, and an output density upper limit. The dataset may also include PID parameters as limit setting values. In addition to the direct upper limit described above, the PID parameters may limit the maximum value of the actual output by defining tolerances for overshoot, etc. The dataset storage unit 21 may store a dataset input via the input device 27, a dataset created by the dataset synthesis unit 25, and a dataset created by the dataset creation unit 26.

[0014] As shown in Table 1, the multiple data sets stored in the data set storage unit 21 include data sets with different limit setting values ​​(output rates), such as a high-output data set with a relatively high maximum output based on the limit setting value and a long-life data set with a relatively low maximum output based on the limit setting value. In particular, the multiple data sets stored in the data set storage unit 21 preferably include one or more open-state data sets (data set 0) that are high-output data sets that can be selected when the thermal insulation material 17 is not attached to the barrel 11, and one or more warm-state data sets (data set 1) that are long-life data sets that can be selected when the thermal insulation material 17 is attached to the barrel 11. A limit setting value may be set for each heater 15 (in Table 1, a limit setting value is set for three barrel heaters). The maximum output based on the limit setting value of the warm-state data set is smaller than the maximum output based on the limit setting value of the open-state data set. In other words, the warm-state data set is a long-life data set with a relatively low maximum output based on the limit setting value.

[0015]

[0016] The dataset storage unit 21 may include, in each dataset, selection criteria that specify the conditions for selecting that dataset, or may separately store a reference table linking each dataset to its selection criteria. The dataset storage unit 21 may also store, as part of the dataset or as external data, a priority order that determines which dataset to select when multiple dataset selection criteria are met. The multiple datasets stored in the dataset storage unit 21 may include a first dataset that can be selected when a first selection criterion is met and a second dataset that can be selected when a second selection criterion is met. Preferably, the multiple datasets further include a standard dataset that can be selected when neither the first nor the second selection criterion is met. In Table 1, dataset 0 may be the standard dataset, dataset 1 may be the first dataset, and dataset 2 may be the second dataset. In this case, the standard dataset includes a limit setting value that maximizes the practical maximum output, and the first and second datasets include limit setting values ​​that reduce the maximum output compared to the standard dataset. The first and second selection criteria are conditions under which the maximum output determined by the limit setting values ​​should be relatively reduced. For example, it is assumed that the first selection criterion is that the heat insulating material 17 is installed, and the second selection criterion is that the power saving mode is selected by input from the input device 27.

[0017] The information acquisition unit 22 acquires at least one of operation information, which is information indicating the state of the injection molding machine and information input by the user. Examples of operation information indicating the state of the injection molding machine include the detection value of the temperature sensor 16, whether or not a heat insulating material is attached as detected by the attachment detector 18, and the output value of the heater 15 (output of the heater control unit 24). Examples of operation information input by the user include an operation mode selected by input via the input device 27.

[0018] The dataset selection unit 23 selects one dataset from the plurality of datasets based on one or more pieces of operating information acquired by the information acquisition unit 22. That is, the dataset selection unit 23 selects a dataset linked to a selection criterion that matches the operating information. When a plurality of datasets satisfy the selection criterion, the dataset may be selected according to a predetermined priority order, or the dataset with the smallest maximum output specified by the limit setting value may be selected.

[0019] The dataset selection unit 23 may also be configured to select a dataset based solely on the operating information input by the user. To allow the user to input the operating information, the dataset selection unit 23 may be configured to display selectable operating information to the user. When selecting a dataset from Table 1, the dataset selection unit 23 may be configured to prompt the user to select one of three modes: "high output," "with thermal insulation," and "power reduction." Note that when the thermal insulation 17 is installed, the temperature of the heater 15 is likely to rise, resulting in an overheated state and a shortened lifespan. Therefore, it is preferable that the dataset selection unit 23 be configured to select dataset 1 for long life, in which a limit setting value is set to reduce the maximum output in order to prevent deterioration of the heater 15 due to heat when the thermal insulation 17 is installed.

[0020] The dataset selection unit 23 may be configured to select a dataset based only on information indicating the state of the injection molding machine. Furthermore, the dataset selection unit 23 may select a dataset based not only on current operating information but also on historical operating information. The dataset selection criterion may be, for example, whether a certain condition is continuously satisfied for a certain period of time or more. Specifically, when the output of the heater 15 is above a certain value and continues to be above the certain value, dataset 1 having a limit setting value that relatively reduces the maximum output may be selected, thereby slowing down the rate of increase in the surface temperature of the heater 15. Furthermore, the dataset selection criterion may be set based on the rate of change of operating information, such as the rate of temperature rise of the temperature sensor 16.

[0021] The heater control unit 24 controls the output of the heater 15 so as to maintain the temperature of the barrel 11 at a set temperature. The heater control unit 24 also limits the output of the heater 15 in accordance with the dataset selected by the dataset selection unit 23. That is, the heater control unit 24 controls the input to the heater 15 so that the output of the heater 15 does not exceed the maximum output specified by the selected dataset. By the heater control unit 24 limiting the maximum output of the heater 15 in accordance with the dataset selected in response to the operating information, deterioration of the heater 15 due to its thermal history can be suppressed, and the life of the heater 15 can be extended.

[0022] The dataset combining unit 25 creates a new dataset calculated from the first dataset and the second dataset and selected when the first selection criterion and the second selection criterion are simultaneously satisfied. When the limit setting value is an output rate or the like, the dataset combining unit 25 may be configured to set the limit setting value of the new dataset to an output rate calculated as the product of the output rate of the first dataset and the output rate of the second dataset, or a value corresponding to the output rate. Alternatively, the dataset combining unit 25 may create a new dataset by combining the smaller of the limit setting value of the first dataset and the limit setting value of the second dataset, converted into the heater 15 output. By providing the dataset combining unit 25 to create a new dataset from the first dataset and the second dataset in this way, the maximum output of the heater 15 can be more appropriately limited in accordance with the operating conditions. The dataset combining unit 25 may create a new dataset each time as needed depending on the operating conditions. However, it is preferable to store the created new dataset in the dataset storage unit 21 so that it can be reused.

[0023] The dataset creation unit 26 creates a new dataset in accordance with user input. The dataset creation unit 26 can be configured to provide a user interface that displays the contents of each element of the dataset and prompts the user to input values ​​for those elements. By providing the dataset creation unit 26 that allows the user to create a new dataset, the maximum output of the heater 15 can be optimized for a variety of operating conditions. It is preferable that the new dataset created by the dataset creation unit 26 be stored in the dataset storage unit 21 so that it can be reused.

[0024] The input device 27 may be any device, such as a keyboard, a mouse, a touchpad, etc. The input device 27 may be integrated with the injection molding control device 20, or may be connected to the injection molding control device 20 via a network.

[0025] As described above, the injection molding machine 1 equipped with the injection molding control device 20 having the data set selection unit 23 that selects an appropriate data set from multiple data sets including a limit setting value that limits the maximum output of the heater 15 based on the operating information can suppress thermal deterioration of the heater 15 and achieve a longer life for the heater 15.

[0026] The following supplementary notes are further disclosed regarding the above-described embodiments and modified examples. (Supplementary Note 1) An injection molding control device (20) controls the heater (15) in an injection molding machine (10) having a barrel (11), one or more heaters (15) that heat the barrel (11), and one or more detectors (16, 18) that detect status values, and includes: a dataset storage unit (21) that stores multiple datasets, each dataset including one or more limit setting values ​​that limit a maximum output of the heater (15); an information acquisition unit (22) that acquires operating information, such as information indicating the status of the injection molding machine (10) and information input by a user; a dataset selection unit (23) that selects one dataset from the multiple datasets based on the one or more pieces of operating information acquired by the information acquisition unit (22); and a heater control unit (24) that controls the output of the heater (15) in accordance with the dataset selected by the dataset selection unit (23).

[0027] (Supplementary Note 2) In the injection molding control device (20) of Supplementary Note 1, the multiple data sets include one or more open data sets that can be selected when no thermal insulation material is attached to the barrel (11) and one or more warm data sets that can be selected when thermal insulation material is attached to the barrel (11), and the maximum output according to the limit setting value of the warm data set may be smaller than the maximum output according to the limit setting value of the open data set.

[0028] (Supplementary Note 3) The injection molding control device (20) of Supplementary Notes 1 and 2 may further include a dataset synthesis unit (25) that creates a new dataset based on the first dataset and the second dataset, which is selected when the first selection criterion and the second selection criterion are simultaneously satisfied, wherein the plurality of datasets include a first dataset that can be selected when a first selection criterion is satisfied and a second dataset that can be selected when a second selection criterion is satisfied.

[0029] (Supplementary Note 4) In the injection molding control device (20) of Supplementary Note 3, the data set storage unit (21) may store the data set created by the data set synthesis unit (25).

[0030] (Supplementary Note 5) The injection molding control device (20) of Supplementary Notes 1 to 4 may further include a data set creation unit (26) that creates a new data set according to a user's input.

[0031] (Supplementary Note 6) In the injection molding control device (20) of Supplementary Note 5, the data set storage unit (21) may store the data set created by the data set creation unit (26).

[0032] (Supplementary Note 7) The injection molding machine (1) includes the injection molding control device (20) of Supplementary Notes 1 to 5, a barrel (11), one or more heaters (15) that heat the barrel (11), and one or more detectors (16, 18) that detect state values.

[0033] Although the present disclosure has been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. Furthermore, these embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these.

[0034] REFERENCE SIGNS LIST 1 Injection molding machine 10 Molding machine body 11 Barrel 12 Screw 13 Nozzle 14 Supply feeder 15 Heater 16 Temperature sensor 17 Heat insulating material 18 Mounting detector 20 Injection molding control device 21 Data set storage unit 22 Information acquisition unit 23 Data set selection unit 24 Heater control unit 25 Data set synthesis unit 26 Data set creation unit 27 Input device 111 Inner cavity 112 Main supply port 121 Motor

Claims

1. 1. An injection molding control device for controlling a heater in an injection molding machine having a barrel, one or more heaters for heating the barrel, and one or more detectors for detecting state values, comprising: a data set storage unit configured to store a plurality of data sets each including one or more limit setting values ​​for limiting a maximum output of the heater; an information acquisition unit that acquires at least one of operational information indicating the state of the injection molding machine and information input by a user; a dataset selection unit that selects one of the plurality of datasets based on one or more pieces of driving information acquired by the information acquisition unit; a heater control unit that limits the output of the heater in accordance with the data set selected by the data set selection unit; An injection molding control device comprising:

2. The plurality of data sets include one or more open data sets that can be selected when no thermal insulation is attached to the barrel, and one or more heated data sets that can be selected when thermal insulation is attached to the barrel, The injection molding control device according to claim 1 , wherein the maximum output according to the limit setting value of the warming data set is smaller than the maximum output according to the limit setting value of the open data set.

3. the plurality of data sets includes a first data set that may be selected if a first selection criterion is met, and a second data set that may be selected if a second selection criterion is met; 3. The injection molding control device according to claim 1, further comprising a dataset synthesis unit that creates a new dataset based on the first dataset and the second dataset, which is selected when the first selection criterion and the second selection criterion are simultaneously satisfied.

4. 4. The injection molding control device according to claim 3, wherein the data set storage unit stores the data set created by the data set synthesis unit.

5. The injection molding control device according to claim 1 or 2, further comprising a data set creation unit that creates a new data set in accordance with a user input.

6. 6. The injection molding control device according to claim 5, wherein the data set storage unit stores the data set created by the data set creation unit.

7. The injection molding control device according to claim 1 or 2; Barrel and one or more heaters for heating the barrel; one or more detectors for detecting state values; An injection molding machine comprising: