Device for controlling injection molding machine

Abstract

The device for controlling an injection molding machine (10) comprises a numerical-value-setting unit (20) that sets numerical values for a plurality of items included in the molding conditions of an injection molding machine and a range-setting unit (24) that sets an input limit range which is a range for limiting input of numerical values. The range-setting unit (24) calculates an input limit range for numerical values set for at least one item using numerical values and coefficients common to each item.

Description

Injection molding machine control device

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

[0002] An injection molding machine repeatedly executes a molding cycle, which includes a mold clamping step, an injection step, a pressure holding step, a measuring step, a mold opening step, and a molded product removal step.

[0003] The mold clamping process is a process of closing the mold and applying a predetermined mold clamping force to the closed mold. The injection process is a process of injecting the molding material into the mold. The pressure holding process is a process of applying pressure (holding pressure) to the molding material injected into the mold. The metering process is a process of metering the molding material in preparation for the next molding cycle. The mold opening process is a process of opening the mold. The molded product removal process is a process of removing the molded product from the mold. The injection process, pressure holding process, and metering process are carried out by an injection device having a cylinder and a screw that can move forward and backward inside the cylinder. The molding material is injected when the screw moves forward, and the molding material is metered when the screw moves backward.

[0004] To obtain an optimal molded product without flash or warpage, it is necessary to determine many molding conditions, such as position, speed, and pressure, for each of the above processes executed in the molding cycle. However, to accommodate external factors such as temperature and humidity, or individual differences between machines, the values ​​set for multiple items included in the molding conditions must always be adjusted.

[0005] On the other hand, in the medical and automotive fields, in order to prevent defective products, significant changes to molding conditions or mass production conditions approved through validation are sometimes not permitted. Therefore, there is a tendency to limit the degree of freedom in adjusting values. Furthermore, in countries where operators have low levels of proficiency, inputting incorrect settings can easily damage machinery such as molds, clamping units, and injection units. To prevent this, it is required to limit the range of values ​​that can be set for molding condition items. Therefore, it is effective to set input limit ranges, which are ranges that limit the input of values ​​set for multiple items included in the molding conditions.

[0006] Japanese Patent Application Laid-Open No. 2020-124829 discloses a molding condition setting value input device that displays the allowable range (input limit range) of setting values ​​for molding condition setting items. In this molding condition setting value input device, the number of operators who can input the allowable range (input limit range) of setting values ​​is limited.

[0007] However, when an input operator inputs an input limit range, the input operator needs to judge the extent of the input limit range, which requires experience, etc. Furthermore, if the input operator inputs an incorrect input limit range, the device may be damaged.

[0008] The present invention aims to solve the above-mentioned problems.

[0009] One aspect of the present invention is a control device for an injection molding machine, which includes a numerical value setting unit that sets numerical values ​​for multiple items included in the molding conditions of the injection molding machine, and a range setting unit that sets an input limit range that is a range for restricting the input of the numerical values, and the range setting unit calculates the input limit range of the numerical value set for at least one of the items using the numerical values ​​and a coefficient common to each of the items.

[0010] According to an aspect of the present invention, the input limit range can be set without requiring the operator to input the input limit range. Therefore, the input limit range can be set without requiring the operator to determine the extent of the input limit range. As a result, it is possible to prevent damage to equipment caused by the numerical values ​​set in the molding condition items.

[0011] Fig. 1 is a block diagram showing the configuration of a control device for an injection molding machine, and Fig. 2 is a diagram showing an example of a screen for setting an input limit range.

[0012] 1 is a block diagram showing the configuration of a control device 10 for an injection molding machine. The control device 10 for an injection molding machine has an information processing unit 12, a storage unit 14, a display unit 16, and an input unit 18.

[0013] The information processing unit 12 processes information. The information processing unit 12 may be a processor including a CPU, an MPU, a GPU, etc. The memory unit 14 stores information. The memory unit 14 includes a volatile memory and a non-volatile memory. A part of the memory unit 14 may be provided in the information processing unit 12. The display unit 16 displays information. The display unit 16 may be a liquid crystal display, etc. The input unit 18 inputs information. The input unit 18 is used for operation by an operator. The input unit 18 may be a mouse, a keyboard, etc., or may be a touch panel arranged on the display screen of the display unit 16.

[0014] The information processing unit 12 has a numerical value setting unit 20, a numerical value acquiring unit 22, a range setting unit 24, a display control unit 26, and a warning unit 28. The numerical value setting unit 20, the numerical value acquiring unit 22, the range setting unit 24, the display control unit 26, and the warning unit 28 are obtained by the information processing unit 12 executing a program stored in the storage unit 14. At least one of the numerical value setting unit 20, the numerical value acquiring unit 22, the range setting unit 24, the display control unit 26, and the warning unit 28 may be realized by an integrated circuit such as an ASIC or an FPGA. At least one of the numerical value setting unit 20, the numerical value acquiring unit 22, the range setting unit 24, the display control unit 26, and the warning unit 28 may also be configured by an electronic circuit including a discrete device.

[0015] The storage unit 14 has a numerical value storage unit 30, a coefficient storage unit 32, a range storage unit 34, and a rated range storage unit 36. Specific information is stored in each of the numerical value storage unit 30, the coefficient storage unit 32, the range storage unit 34, and the rated range storage unit 36. The numerical value storage unit 30, the coefficient storage unit 32, the range storage unit 34, and the rated range storage unit 36 ​​may be provided in a single memory device or in separate memory devices.

[0016] The numerical value setting unit 20 sets numerical values ​​for a plurality of items included in the molding conditions of the injection molding machine. The plurality of items include at least two of the number of injection stages, injection speed, VP switching position, number of dwell stages, dwell pressure, dwell time, pre-metering pressure, and pre-metering dwell time.

[0017] The number of injection stages is the number of stages at which the injection speed is switched in stages. The injection speed is the speed at which the molding material is filled into the mold cavity, and is set according to the number of injection stages. The VP switch position is the position at which speed control (V) is switched to pressure control (P). The number of dwelling stages is the number of stages at which the dwelling pressure is switched in stages. Dwelling pressure is the pressure applied to prevent backflow of the molding material injected into the mold, and is set according to the number of dwelling stages. Dwelling time is the time for which dwelling pressure is continued, and is set according to the number of dwelling stages. The pre-metering pressure is the dwelling pressure immediately before the metering process is performed, and the pre-metering dwelling time is the time for which the pre-metering pressure is continued.

[0018] The numerical value setting unit 20 sets the numerical values ​​entered by the operator using the input unit 18 to the items. If the operator has not entered a numerical value for any item, the numerical value setting unit 20 sets a default value prepared in advance for that item. After setting a numerical value for each item, the numerical value setting unit 20 stores the numerical value set for each item in the numerical value storage unit 30 of the storage unit 14.

[0019] The numerical value acquiring unit 22 acquires numerical values ​​set for a plurality of items included in the molding conditions. In this case, the numerical value acquiring unit 22 reads the numerical value of each item stored in the numerical value storage unit 30 of the storage unit 14 from the numerical value storage unit 30 as the current numerical value (current value) set for that item.

[0020] The range setting unit 24 sets an input limit range. The input limit range is a range for restricting the input of a numerical value set in an item. This numerical value is input by an operator. The input limit range has an upper limit value and a lower limit value. The range setting unit 24 calculates the input limit range of a numerical value set in at least one of the multiple items. In this case, the range setting unit 24 uses a numerical value and a coefficient. The range setting unit 24 changes the upper limit value and lower limit value of the input limit range according to the coefficient, using the current value acquired by the numerical value acquisition unit 22 as a reference.

[0021] The numerical values ​​are current values ​​acquired by the numerical value acquiring unit 22. The coefficients are coefficients common to multiple items included in the molding conditions of the injection molding machine, and include a first coefficient and a second coefficient. The first coefficient and the second coefficient are stored in the coefficient storage unit 32 of the storage unit 14. The first coefficient and the second coefficient may be default values ​​prepared in advance, or may be values ​​input by the operator through an input operation using the input unit 18.

[0022] The first coefficient is a coefficient used to calculate the upper limit value of the input limit range. The second coefficient is a coefficient used to calculate the lower limit value of the input limit range. In this embodiment, the range setting unit 24 calculates the upper limit value of the input limit range by adding the first coefficient to "1" and multiplying the current value by the addition result. The range setting unit 24 also calculates the lower limit value of the input limit range by subtracting the second coefficient from "1" and multiplying the current value by the subtraction result.

[0023] The range setting unit 24 calculates the upper and lower limit values ​​of the input limit range of the numerical value to be set for an item selected by the operator from among the multiple items included in the molding conditions. When multiple items are selected by the operator, the range setting unit 24 collectively calculates the upper and lower limit values ​​of the input limit range of the numerical value to be set for each item.

[0024] After calculating the upper and lower limit values ​​of the input limit range, the range setting unit 24 compares the input limit range with the rated range. The range setting unit 24 sets the narrower of the input limit range or the rated range. The rated range is a range in which numerical input is restricted according to the specifications of the injection molding machine, and has upper and lower limit values. The upper and lower limit values ​​of the rated range are stored in the rated range storage unit 36 ​​of the storage unit 14. When the range setting unit 24 sets the input limit range, it stores the upper and lower limit values ​​of the input limit range in the range storage unit 34 of the storage unit 14.

[0025] When the display control unit 26 receives a request to set an input limit range from the input unit 18, it displays a setting screen for setting the input limit range on the display unit 16. Fig. 2 is a diagram showing an example of the setting screen for the input limit range.

[0026] The setting screen displays the current value, maximum value, and minimum value for each item included in the molding conditions. The setting screen has an item display field 40, a current value display field 42, a maximum value display field 44, and a minimum value display field 46.

[0027] The item display field 40, current value display field 42, maximum value display field 44, and minimum value display field 46 are arranged at intervals in a first direction. Fig. 2 shows an example of an arrangement along the horizontal direction of the setting screen. A plurality of item display fields 40, current value display fields 42, maximum value display fields 44, and minimum value display fields 46 are each arranged at intervals in a second direction perpendicular to the first direction. Fig. 2 shows an example of an arrangement along the vertical direction of the setting screen.

[0028] An item is displayed in the item display field 40. The current numerical value set for the item is displayed in the current value display field 42. The numerical value displayed in the current value display field 42 is set by the numerical value setting unit 20 and acquired by the numerical value acquisition unit 22. The maximum value display field 44 displays the current upper limit value of the input limit range. The minimum value display field 46 displays the current lower limit value of the input limit range. The upper limit value of the input limit range displayed in the maximum value display field 44 and the lower limit value of the input limit range displayed in the minimum value display field 46 are default values ​​or values ​​entered by the operator.

[0029] The setting screen also includes check boxes 48, a select all button 50, and a cancel all button 52. The check boxes 48 are associated one-to-one with the multiple item display fields 40 and are arranged near each item display field 40. The select all button 50 is a button for selecting all items displayed in the item display fields 40 at once. The cancel all button 52 is a button for canceling the selection of all items displayed in the item display fields 40 at once. Note that an arbitrary item is selected by a selection operation by the operator using the input unit 18. When an item displayed in the item display field 40 is selected, a check mark is displayed in the check box 48. Therefore, the operator can select the item for which he / she wishes to set the input limit range while checking the current numerical value set for each item of the molding conditions and the input limit range of that numerical value.

[0030] The setting screen further includes a first coefficient display field 54, a second coefficient display field 56, and an execute button 58. The first coefficient is displayed in the first coefficient display field 54, and the second coefficient is displayed in the second coefficient display field 56. The first coefficient displayed in the first coefficient display field 54 and the second coefficient displayed in the second coefficient display field 56 are stored in the coefficient storage unit 32.

[0031] The execute button 58 is a button for executing the setting of the input limit range. When the execute button 58 is operated using the input unit 18, setting of the input limit range for the numerical value to be set in the item corresponding to the check box 48 with a check mark displayed starts. In this case, the upper and lower limit values ​​of the input limit range are set by the range setting unit 24 using the numerical value displayed in the current value display field 42, the first coefficient displayed in the first coefficient display field 54, and the second coefficient displayed in the second coefficient display field 56. Therefore, the operator can set the input limit range without having to determine the extent of the input limit range.

[0032] When the range setting unit 24 sets the upper and lower limits of the input limit range, the display control unit 26 displays the upper limit value in the maximum value display field 44 and the lower limit value in the minimum value display field 46. Therefore, the operator can confirm the value set for the item by comparing it with the input limit range for that value. The operator can also change the first and second coefficients as needed to reset the input limit range. Note that when the range setting unit 24 sets the narrower of the input limit range or the rated range, damage to the machine can be suppressed even if an incorrect coefficient is entered.

[0033] The setting screen further includes a valid / invalid display field 60. The valid / invalid display field 60 displays the input limit range in a pull-down format so that the input limit range can be selected as valid or invalid. The selection of whether to enable or disable the input limit range is made by a selection operation of the operator using the input unit 18.

[0034] When the input restriction range is valid, the input of a numerical value set in an item is restricted to the input restriction range set by the range setting unit 24. In this case, if there is a request to change the numerical value to a value outside the input restriction range, the numerical value setting unit 20 discards the value outside the input restriction range and maintains the current numerical value.

[0035] If the input restriction range is invalid, the restriction on the input of a numerical value set in the item is lifted even if the input restriction range has been set by the range setting unit 24. In this case, if there is a request to change the numerical value to a value outside the input restriction range, the numerical value setting unit 20 changes the numerical value to a value outside the input restriction range.

[0036] The warning unit 28 issues a warning when the input limit range is valid and there is a request to change a numerical value to a value outside the input limit range. In this case, the warning unit 28 may display a warning message on the display unit 16, output a warning message from a speaker, or light or blink a warning light-emitting unit.

[0037] The above embodiment may be modified as follows.

[0038] (Variation 1) A stop unit may be provided that brings the injection molding machine to an emergency stop when the input limit range is valid and there is a request to change the numerical value to a value outside the input limit range. In this case, the warning unit 28 may be removed, or may issue a warning without being removed.

[0039] (Variation 2) A first coefficient input range, which is a range within which the first coefficient can be input, may be set. In this case, when there is a request to change the first coefficient to a value outside the first coefficient input range, the range setting unit 24 may calculate the upper limit of the input limit range using a default value as the first coefficient. Furthermore, the display control unit 26 may display on the setting screen that the value input as the first coefficient is inappropriate, or may display on the setting screen that the input limit range was calculated using the default value.

[0040] Similarly, a second coefficient input range, which is a range within which the second coefficient can be input, may be set. In this case, when there is a request to change the second coefficient to a value outside the second coefficient input range, the range setting unit 24 may calculate the lower limit of the input limit range using a default value as the second coefficient. Furthermore, the display control unit 26 may display on the setting screen that the value input as the second coefficient is inappropriate, or may display on the setting screen that the input limit range was calculated using the default value.

[0041] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

[0042] [Invention] The invention that can be understood from the above-described embodiment and modifications will be described below.

[0043] (1) The present invention is a control device (10) for an injection molding machine, comprising a numerical value setting unit (20) that sets numerical values ​​for a plurality of items included in the molding conditions of the injection molding machine, and a range setting unit (24) that sets an input limit range that is a range for restricting the input of the numerical values, and the range setting unit calculates the input limit range of the numerical value set for at least one of the items using the numerical values ​​and a coefficient common to each of the items.

[0044] This allows the input limit range to be set without requiring the operator to input it. Therefore, the input limit range can be set without requiring the operator to determine the extent of the input limit range. As a result, it is possible to prevent damage to equipment or molding defects caused by the numerical values ​​set in the molding condition items.

[0045] (2) In the control device for an injection molding machine according to the present invention, the range setting unit may collectively calculate the input limit ranges of the numerical values ​​set for each of the items. This allows the input limit ranges to be set more quickly than when the numerical values ​​set for each item are calculated individually. Furthermore, it is possible to eliminate the need for operator operations, etc., required to calculate each input limit range.

[0046] (3) In the control device for an injection molding machine, the range setting unit may calculate the input limit range of the numerical value set for the item selected by an operator from among the plurality of items. This makes it possible to set the input limit range for only the item desired by the operator.

[0047] (4) The present invention may be a control device for an injection molding machine, comprising: a numerical value acquisition unit (22) that acquires the numerical value set for each of the items; and a display control unit (26) that causes a display unit (16) to display the numerical value, the upper limit value of the input limit range, and the lower limit value of the input limit range for each of the items, and the range setting unit may calculate the upper limit value and the lower limit value. This allows the operator to set the input limit range while checking the current numerical value set for each item of molding conditions and the input limit range for that numerical value. Furthermore, the operator may be given an opportunity to reset the input limit range.

[0048] (5) In the control device for an injection molding machine according to the present invention, the range setting unit may calculate the input limit range using a first coefficient that is the coefficient used to calculate an upper limit value of the input limit range and a second coefficient that is the coefficient used to calculate a lower limit value of the input limit range. This makes it possible to appropriately set the input limit range.

[0049] (6) The present invention may be a control device for an injection molding machine, including a coefficient storage unit (32) that stores the coefficients input by an operator, and the range setting unit may calculate the input limit range using the coefficients stored in the coefficient storage unit. This makes it possible to calculate the input limit range taking into account the operator's requests.

[0050] (7) The present invention provides a control device for an injection molding machine, the control device including a rated range storage unit (36) that stores a rated range in which the input of the numerical values ​​is limited according to the specifications of the injection molding machine, and the range setting unit may set the narrower of the input limit range or the rated range. This allows the range for limiting the input of numerical values ​​set in molding condition items to be appropriately set. Furthermore, even if an operator incorrectly inputs a coefficient used to calculate the input limit range, damage to the machine or molding defects can be prevented.

[0051] (8) In the control device for an injection molding machine according to the present invention, when a request is made to change the numerical value to a value outside the input limit range, the numerical value setting unit may discard the value outside the input limit range and maintain the current numerical value. This makes it possible to reliably prevent damage to the machine or molding defects.

[0052] REFERENCE SIGNS LIST 10: Control device 12: Information processing unit 14: Storage unit 16: Display unit 18: Input unit 20: Numerical value setting unit 22: Numerical value acquisition unit 24: Range setting unit 26: Display control unit 28: Warning unit 30: Numerical value storage unit 32: Coefficient storage unit 34: Range storage unit 36: Rated range storage unit

Claims

1. a numerical value setting unit for setting numerical values ​​for a plurality of items included in the molding conditions of the injection molding machine; a range setting unit that sets an input limit range for limiting the input of the numerical value; Equipped with The range setting unit calculates the input limit range of the numerical value set for at least one of the items using the numerical value and a coefficient common to each of the items.

2. The control device for an injection molding machine according to claim 1, The range setting unit collectively calculates the input limit ranges of the numerical values ​​set for each of the items.

3. The control device for an injection molding machine according to claim 1 or 2, The range setting unit calculates the input limit range of the numerical value set for the item selected by an operator from among the plurality of items.

4. The control device for an injection molding machine according to claim 1 or 2, A numerical value acquiring unit that acquires the numerical values ​​set for each of the items; a display control unit that causes a display unit to display the numerical value, an upper limit value of the input limit range, and a lower limit value of the input limit range for each of the items; The range setting unit calculates the upper limit value and the lower limit value.

5. The control device for an injection molding machine according to claim 1 or 2, The range setting unit calculates the input limit range using a first coefficient, which is the coefficient used to calculate an upper limit value of the input limit range, and a second coefficient, which is the coefficient used to calculate a lower limit value of the input limit range.

6. The control device for an injection molding machine according to claim 1 or 2, a coefficient storage unit for storing the coefficients input by an operator; The range setting unit calculates the input limit range using the coefficients stored in the coefficient storage unit.

7. The control device for an injection molding machine according to claim 1 or 2, a rated range storage unit that stores a rated range in which the input of the numerical value is limited according to the specifications of the injection molding machine; The range setting unit sets either the input limit range or the rated range, whichever is narrower.

8. The control device for an injection molding machine according to claim 1 or 2, A control device for an injection molding machine, wherein when there is a request to change the numerical value to a value outside the input limit range, the numerical value setting unit discards the value outside the input limit range and maintains the current numerical value.