JP2019059082A - Arithmetic processing unit, arithmetic method and program of arithmetic processing unit - Google Patents

Abstract

To set unit space information for quality determination of molded article.SOLUTION: The arithmetic processing unit has a monitoring period setting part for specifying monitoring initiation point and setting a prescribed period from the monitoring initiation point as a first monitoring period, a monitoring timing setting part for setting a plurality of monitoring timings in the monitoring period based on specified division number, and a unit space information setting part for setting unit space information used for a monitoring processing of a molded article in the monitoring timing set by the monitoring timing setting part by using obtained measurement item data during manufacture of good products.SELECTED DRAWING: Figure 6

Description

  The present technology relates to an arithmetic processing unit, an arithmetic method of the arithmetic processing unit, and a program. In particular, the present invention relates to the technical field of generating reference information for determining non-defective items of molded articles manufactured by an injection molding apparatus.

  An injection molding quality monitoring system is known which comprises a sensor installed in an injection molding apparatus and a monitoring device. The injection molding quality monitoring system detects the behavior of a molding material such as resin in a mold provided in the injection molding apparatus by the above sensor, and can output it as a waveform to an information processing apparatus such as a personal computer in real time. In the injection molding quality monitoring system, it becomes possible to monitor the measurement value based on the detection signal of the sensor and to identify a defective product. As an injection molding quality monitoring system, there exists a thing of patent document 1, for example.

JP 2008-36975 A

  Patent Document 1 discloses a technique in which a sensor (load cell) provided in an injection molding apparatus detects the pressure of resin in a cavity, and the detection signal of the sensor is sampled by an amplifier apparatus.

  In identifying defective products using such an injection molding quality monitoring system, it has been necessary for the user to set monitoring timings to be monitored at his or her own discretion. Therefore, it may be difficult to set a monitoring timing suitable for identifying a defective product unless there is a certain degree of experience with the injection molding quality monitoring system.

  Therefore, the present technology aims to provide a function capable of easily setting the monitoring timing even for an inexperienced user about the injection molding quality monitoring system.

The arithmetic processing unit according to the present technology is an arithmetic processing unit that generates unit space information for non-defective item determination that is performed by a monitoring device that inputs detection signals of one or more measurement items by a sensor provided in an injection molding device. A monitoring period setting unit that specifies a monitoring start time and sets a predetermined period as the monitoring period from the monitoring start time, and sets a plurality of monitoring timings within the monitoring period based on the designated number of divisions Monitoring timing setting unit, and unit space information setting unit for setting unit space information used for monitoring processing of a molded article at the monitoring timing set by the monitoring timing setting unit, based on the acquired measurement item data at the time of non-defective product manufacturing And.
That is, the monitoring timing is automatically set by setting at least the monitoring start time and the division number of the monitoring period. Further, at each monitoring timing, unit space information used in the process of determining the non-defective item of the molded item is calculated based on the acquired measurement item data at the time of non-defective item manufacturing.
Here, the monitoring timing refers to the timing at which the quality determination within the manufacturing process of the molded product is performed. Before mass-producing molded articles, the monitoring device acquires unit space information for non-defective item determination at each monitoring timing in advance, and performs non-defective item determination based on the unit space information.
Further, the measurement item data refers to data of measurement items used when performing the non-defective item determination. As measurement items, for example, various items necessary for evaluating the quality of molded articles, such as resin pressure, resin flow rate, resin temperature, mold surface temperature, etc., can be considered.

In the arithmetic processing unit according to the present technology described above, the monitoring period setting unit may set a gate seal period as the monitoring period.
When the detection signal used for determining the quality of the molded product is the resin pressure in the mold, the monitoring timing is preferably set during the gate seal period.
Because, the gate seal period is a period until the resin filled in the mold solidifies. Therefore, although the value of such a period is useful for evaluation of the quality of a molded article, it is because the period after solidification may not have much meaning.

In the arithmetic processing device according to the present technology described above, it is conceivable that the monitoring period setting unit specifies the monitoring start time using the time when the detection signal reaches the set predetermined threshold.
Considering the detection signal of the pressure sensor, the rising timing is the timing immediately after the molding material is filled in the mold. Therefore, the timing of the rise is specified as the monitoring start time.

In the arithmetic processing device according to the present technology described above, it is considered that the monitoring period setting unit specifies a time point that is a predetermined time before the time when the detection signal reaches the set predetermined threshold value as the monitoring start time point. Be
That is, monitoring of the molded article is started before a predetermined period before the rising timing of the detection signal of the pressure sensor.

In the arithmetic processing device according to the present technology described above, the unit space information setting unit may set the unit space information using a value for each monitoring timing of each of a plurality of measurement items.
In this way, unit space information is set in consideration of various measurement items and monitoring timings.

In the arithmetic processing unit according to the present technology described above, the unit space information may be information used to calculate a value obtained by squaring the Mahalanobis distance.
That is, unit space information is set to replace the value of each multi-dimensional measurement item having different units with a unit as a common one dimension.

The calculation method of the calculation processing device according to the present invention generates unit space information for non-defective item determination performed by a monitoring device which inputs detection signals of one or more measurement items by a sensor provided in an injection molding device. The arithmetic processing unit specifies a monitoring start time, and sets a predetermined period as the monitoring period from the monitoring start time, and sets a plurality of monitoring timings in the monitoring period based on the set number of divisions. And a process of calculating unit space information used for the monitoring process of a molded article at the set monitoring timing based on the acquired measurement item data at the time of non-defective product manufacturing.
A program according to the present invention is a program that causes an arithmetic processing unit to execute the processing of each of the above steps.

  According to the present technology, it is possible to set unit space information used to determine the quality of a molded product manufactured by the injection molding apparatus.

It is an explanatory view of a quality monitoring system of an embodiment. It is explanatory drawing of the display screen by the management software of embodiment. It is explanatory drawing of a structure of the monitoring apparatus of embodiment. It is an explanatory view of composition of a computer device of an embodiment. It is explanatory drawing of the measured waveform data of embodiment. It is a flowchart of the unit space information setting process of embodiment. It is explanatory drawing of the data used for the non-defective item determination of embodiment. It is a flowchart of mass production monitoring processing of an embodiment.

Hereinafter, embodiments will be described in the following order.
<1. Configuration of Quality Monitoring System>
<2. Configuration of monitoring device>
<3. Computer device configuration>
<4. Overview of Quality Monitoring System>
<5. Unit space setting process>
<6. Mass production monitoring process>
<7. Summary and Modifications>
<8. Program and storage medium>

<1. Configuration of Quality Monitoring System>
Hereinafter, embodiments according to the present invention will be described. First, an injection molding quality monitoring system 100 (also simply referred to as a "quality monitoring system 100") including a monitoring device 1, an injection molding device 2 and a personal computer 4 according to an embodiment of the present invention will be described.
FIG. 1 is a diagram showing a configuration outline of the quality monitoring system 100. As shown in FIG.
As illustrated, the quality monitoring system 100 includes a monitoring device 1, an injection molding device 2, a dedicated amplifier 3, and a personal computer 4 (hereinafter also referred to as “computer device 4”).

  The injection molding apparatus 2 generally comprises a mold 10 disposed at a predetermined position, an injection unit 11 having a mechanism for injecting and filling a resin material to the mold 10, and an injection unit 11 as generally known. The molding control unit 12 is configured to perform and control a series of injection molding operations by controlling the injection operation of the above and the opening / closing operation of the mold 10 and the like.

For example, an upper mold and a lower mold are disposed in the mold 10, and the upper mold is opened and closed by a mechanism provided in the injection unit 11 with respect to a lower mold disposed in a molding stage, for example. In a state where the upper mold is closed to the lower mold, for example, the resin material is injected by the injection cylinder of the injection unit 11 to the gate provided in the upper mold, and the cavity in the mold 10 is filled with the resin material Ru. After filling, when the required time has elapsed, the upper mold is opened, and the resin molded product is taken out from the cavity.
An in-mold sensor 31 is disposed in the mold 10. For example, it is a temperature sensor which detects the temperature of the filled resin material, and a pressure sensor which detects the pressure of the resin material.
The structure and type of the mold 10 are not particularly limited, and various types are conceivable.

The injection unit 11 is provided with a mechanism necessary for injection molding, such as a resin material injection mechanism for the mold 10, a mold clamping mechanism, an injection cylinder mechanism, an injection motor, and the like.
Further, the injection unit 11 is provided with an in-injection unit sensor 32 and a sensor amplifier 33. As the in-ejection section sensor 32, there are a temperature sensor for detecting the temperature of the resin material in the injection process, a pressure sensor for detecting pressure, a position sensor for calculating the injection speed, and the like.
In the present embodiment, the mechanism and structure of the injection unit 11, such as a cylinder structure, a structure of a clamp mechanism, a runner structure, a nozzle structure, a heater arrangement, a motor arrangement, a material injection mechanism, etc. It may be of the type.

The forming control unit 12 includes, for example, a microcomputer having a read only memory (ROM), a random access memory (RAM), and a central processing unit (CPU).
The forming control unit 12 performs drive control of each unit by the injection unit 11. For example, injection motor control, mold stage operation control, operation control of the mold opening / closing mechanism, operation control of the nozzle opening / closing mechanism, heater control, material input operation control, etc. are performed. This causes a series of injection molding operations to be performed.

The detection signal S1 of the in-mold sensor 31 is converted into a voltage value by a dedicated amplifier 3 disposed separately from the injection molding apparatus 2, for example. And it is supplied to the monitoring apparatus 1 as detection signal Vs1 converted into the voltage signal.
The detection signal S2 of the in-emission unit sensor 32 is converted into a voltage value by a sensor amplifier 33 provided in the emission unit 11, for example. And it is supplied to the monitoring apparatus 1 as detection signal Vs2 converted into the voltage signal.

Here, although two detection signals are shown as the detection signals Vs1 and Vs2, the detection signal Vs1 is a generic name of the detection signal from the in-mold sensor 31, and the detection signal Vs2 is the detection signal from the in-ejection area sensor 32. It is a generic term. In the case where a plurality of sensors are disposed as the in-mold sensor 31 or in the case where a plurality of sensors are disposed as the in-mold sensor 32, it is naturally assumed.
Therefore, the detection signals Vs1 and Vs2 do not indicate detection signals of only two systems, but merely indicate that any detection signals of the in-mold sensor 31 and the in-emission sensor 32 can be input to the monitoring device 1 Absent.
The monitoring apparatus 1 is provided with an n-channel input system, and can simultaneously input n detection signals. Therefore, the detection signals Vs1 of n sensors may be supplied to the monitoring device 1 as the in-mold sensors 31 or the detection signals Vs2 of n sensors as the in-ejection sensors 32 may be supplied to the monitoring device 1 Good. Furthermore, the detection signals Vs1 and Vs2 of one or more systems as the in-mold sensor 31 and the in-ejection sensor 32 may be distributed to n channels and supplied to the monitoring device 1.
Which detection signal is to be input to the monitoring device 1 depends on the structure, type, molded article, number of mounted sensors, and the contents of measurement / monitoring desired to be executed, etc., of the actual injection molding device 2 or mold 10 It may be determined appropriately.
Although not shown, various sensors may be provided on peripheral equipment of the injection molding apparatus 2, for example, a temperature controller for cooling, a vacuum drawing apparatus, etc., and detection signals of these sensors are supplied to the monitoring apparatus 1 It is also assumed that

Various types of communication are enabled between the monitoring device 1 and the forming control unit 12. In FIG. 1, various timing signals STM are transmitted from the forming control unit 12 to the monitoring device 1 as one of the communications, and a notification signal SI is transmitted from the monitoring device 1 to the forming control unit 12. Which indicates that.
One of the timing signals STM is, for example, a signal that indicates the start / end timing of one injection molding cycle. The monitoring device 1 can detect a molding period of one cycle by resin injection of one shot by the timing signal STM, and can perform logging and determination of various detection signals during that period.
As other timing signals STM, as described later, a signal indicating the start / end timing of the mold clamping period, a signal indicating the transition timing of the process, or the switching timing of the control method (speed control, pressure control) A signal etc. can be considered.

  The notification signal SI from the monitoring device 1 is a signal for notifying the results of various detection information and determination information. For example, it is a signal such as an alarm notification at the time of an abnormal determination in which a molding failure or the like is estimated, or a notification of the rising timing / falling timing of the detection signal waveform. The forming control unit 12 can perform various operation control in accordance with the notification signal SI of these contents.

The measurement results such as temperature and pressure by the monitoring device 1 can be browsed by the computer device 4 connected to the monitoring device 1 by the wired or wireless communication path US. The communication path US is realized by, for example, a LAN (Local Area Network) cable or the like.
Management software for managing the measurement of various detection signals by the monitoring device 1 is installed in the computer 4. With this management software, a worker or the like can view the measurement result by the monitoring device 1 through the display of the computer device 4.
In addition, workers and the like can perform various numerical settings by setting using management software.
Furthermore, it is possible to record the measurement result in a predetermined storage device such as a hard disk drive (HDD) or a solid state disk (SSD) in the computer device 4.

FIG. 2 shows an example of display contents of the management screen 90 presented on the screen of the computer 4 by the management software. As shown in the figure, the management screen 90 can display the measurement results of detection signals from various sensors in the form of waveforms, and also allows predetermined values (eg, peak value, integral value, rise timing value, The down timing value etc.) is shown. In addition, operators are provided for the operator to input various settings.

<2. Configuration of monitoring device>
FIG. 3 shows the internal configuration of the monitoring device 1.
The monitoring device 1 includes an arithmetic unit 20, an input unit 21, an A / D converter 22, a buffer and IF unit 23, and a memory unit 24.

The input unit 21 can input n channels of the detection signals Vs1 and Vs2. In the example of the figure, eight channel inputs are assumed, and input channels are shown as I1 to I8.
The detection signals Vs1 and Vs2 input to the input channels I1 to I8 are signals obtained by converting the detection information into voltage levels by the dedicated amplifier 3 or the sensor amplifier 33 as described above.
The detection signal Vs1 or Vs2 is input to all or part of the channels I1 to I8. That is, detection signals of one or a plurality of sensors provided in the injection molding apparatus 2 as the in-mold sensor 31 and the in-injection sensor 32 can be simultaneously input to the required channels.

The A / D converter 22 can have the same number of simultaneous inputs as the number of input channels. Therefore, in the example of the figure, it is considered as an A / D converter of 8-channel input.
The A / D converter 22 converts the input detection signals of the channels I1 to I8 into digital data according to the voltage value, and supplies the digital data to the buffer and IF unit 23.

The buffer and IF unit 23 transfers the detection signals of the respective channels I1 to I8 to the operation unit 20, and transmits / receives communication data between the operation unit 20 and the external device (the computer apparatus 4 or the forming control unit 12). It shows in summary.
For example, digital data (detection value Ddet to be described later) of detection signals of a plurality of channels input simultaneously from A / D converter 22 is temporarily buffered by buffer and IF unit 23 while detecting information at each time point The time information (time value Tdet to be described later) at the sampling time of the detection signal is sequentially transferred to the calculation unit 20 as
Further, the buffer / IF unit 23 transmits the notification signal SI from the calculation unit 20 to the forming control unit 12 from the terminal TM2. Further, various timing signals STM from the forming control unit 12 are temporarily taken in from the terminal TM1 to the buffer and IF unit 23, and sequentially transferred to the operation unit 20 together with time information.
Further, various information communication between the operation unit 20 and the computer device 4 is executed by the communication path US connected to the terminal TM3 (for example, a LAN connector terminal) via the buffer and the IF unit 23.

The arithmetic unit 20 is constituted by, for example, a microcomputer having a ROM, a RAM, and a CPU.
In the present embodiment, the calculation unit 20 performs processing of storing the detection signal value at each time point input to each input channel of the input unit 21 as the log data in the memory unit 24.
For example, processing is performed to store values for each sample for the detection signals of the channels I1 to I8 converted to digital values by the A / D converter 22.
The calculation unit 20 also calculates an evaluation value using the detection signal value input to the input unit 21 at each monitoring timing set in the monitoring period of the injection molding apparatus 2.
Furthermore, the calculation unit 20 performs a process of obtaining the determination result of the injection molding situation using the calculated evaluation value. Further, output processing of the notification signal SI corresponding to the determination processing is performed.
A specific processing example of the computing unit 20 having these functions will be described later.

The memory unit 24 collectively shows a memory area that can be used by the calculation unit 20 as, for example, a ROM, a work memory, a non-volatile memory, or the like.
The memory unit 24 is used, for example, as a storage area of log data by the processing of the calculation unit 20. The memory unit 24 is also used as a work area for various arithmetic processing. The memory unit 24 is also used as a storage area of a program for realizing various processes of the arithmetic unit 20.

<3. Computer device configuration>
FIG. 4 shows the internal configuration of the computer device 4.
The CPU 41 of the computer device 4 executes various processes in accordance with a program stored in the ROM 42 or a program loaded from the storage unit 48 into the RAM 43. The RAM 43 also stores data necessary for the CPU 41 to execute various processes.
The CPU 41, the ROM 42 and the RAM 43 are mutually connected via a bus 44. An input / output interface 45 is also connected to the bus 44.
The input / output interface 45 includes an input unit 46 including a keyboard, a mouse, a touch panel and the like, a display including a LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) panel and the like, and a speaker and the like. A communication unit 49 is connected which performs communication processing with the monitoring device 1 via the communication path US connected via the communication path US connected with the unit 47, HDD, flash memory device, etc., and the terminal TM3, and communication via the Internet. ing.

In the present embodiment, the CPU 41 particularly has functions as a monitoring period setting unit 41a, a monitoring timing setting unit 41b, and a unit space information setting unit 41c.
The monitoring period setting unit 41a specifies a monitoring start time, and performs processing of setting a predetermined period as the monitoring period from the specified monitoring start time.
Further, the monitoring timing setting unit 41 b performs processing of setting a plurality of monitoring timings in the monitoring period based on the set number of divisions.
Furthermore, the unit space information setting unit 41c sets the unit space information used for the monitoring process of the molded product at the monitoring timing set by the monitoring timing setting unit 41b based on the acquired measurement item data at the time of manufacturing the non-defective product.
A specific processing example of the CPU 41 having these functions will be described later.

<4. Overview of Quality Monitoring System>
An outline of unit space setting processing in the quality monitoring system, which is executed in the computer device 4 of the present embodiment, will be described. The unit space setting process of the present embodiment is a process of setting a monitoring timing from within one molding cycle, and setting unit space information to be used for non-defective item determination from detection signals at each monitoring timing.

  FIG. 5A shows an example of the waveform of the detection signal detected by the in-mold sensor 31 or the sensor as the in-injection sensor 32. FIG. The vertical axis is the detected value (Ddet), and the horizontal axis is time. For example, the waveform PR of the solid line is the detected value of the pressure sensor, and the waveform TP of the broken line is the temperature inside the mold.

  These are, for example, detection signal waveforms in one molding cycle corresponding to one shot of resin injection. Time point T0 to T1 is a period of one molding cycle. In this one molding cycle, for example, the upper mold and the lower mold of the mold 10 are closed, and the resin material is injected into the mold 10 by the cylinder of the injection unit 11. Steps including measurement, cooling, mold opening, and extrusion of molded articles are included.

In order to evaluate the detection signal of one molding cycle, normally, an evaluation value obtained from the detection signal of each monitoring timing in this period T0 to T1 is required.
In the present embodiment, the MT (Maharanobis Taguchi) method is used as a method of calculating the evaluation value.
If the manufacturing condition parameters of the facility include various measurement items and measurement points (monitoring timing), and they are in a mutually affecting relationship, one item changes in an undesired direction. It is desirable to comprehensively monitor all the items included in the manufacturing condition parameters in consideration of the possibility of
In such a case, it is preferable to use the MT method, which is a method of one-dimensionalizing a plurality of mutually affecting items in consideration of the correlation in each dimension.
In the MT method, a value obtained by squaring the Mahalanobis distance is used as an evaluation value indicating how similar to the reference item group. Details of the Mahalanobis distance will be described later.

By the way, the meaning of the detection signal is different for each process. For example, the detection value Ddet of the mold temperature is useful for evaluating the quality of a molded article while the mold 10 is closed, but after the mold 10 is opened, it does not make much sense. is there.
As described above, in order to evaluate the quality of a molded article, it is necessary to set an appropriate monitoring timing in the process. However, without a certain level of experience with the quality monitoring system, it may be difficult to set a suitable timing for identifying defective products.
Therefore, in the present embodiment, the following processing is performed to determine the quality of the molded product by the quality monitoring system.

<5. Unit space information setting process>
The unit space information setting process in the quality monitoring system of the present embodiment will be described using FIG. 5 to FIG.
The unit space setting process is a process of determining the monitoring timing when the monitoring device 1 executes the mass production monitoring process to be described later, and calculating unit space information which is information to be used for quality evaluation of molded articles at the monitoring timing. is there. The unit space information setting process is performed by the CPU 41 of the computer device 4.

First, in step S101 of FIG. 6, the CPU 41 acquires, from the storage unit 48, data of detection signals for each measurement item in one molding cycle of a non-defective product. The CPU 41 acquires, for example, non-defective detection signal data for 100 cycles. The detection signal data is obtained by the CPU 41 from the monitoring device 1 that has measured the data, and is stored in the storage unit 48.
As measurement items of the detection signal data to be acquired, various items such as resin pressure, flow velocity of resin, resin temperature, mold surface temperature, etc., which are necessary for evaluating the quality of a molded product can be considered.

Next, the CPU 41 performs monitoring period setting processing in step S102. That is, the CPU 41 sets a partial period in one molding cycle as a monitoring period. Thus, a period useful for quality evaluation can be set as a monitoring period for each measurement item.
There are various ways of setting the monitoring period. For example, it is conceivable to set the mold clamping period of time points Ts1 to Te1 shown in FIG. 5B as the monitoring period. This period is a period in which a plurality of steps from mold clamping to mold opening are performed. That is, only the period in which the mold 10 is closed is set as the monitoring period. The monitoring device 1 acquires the value of the detection value Ddet of the monitoring period of this time point Ts1 to Te1 by acquiring the mold clamping period signal of the waveform of FIG. 4B as one of the timing signals STM from the molding control unit 12.

Alternatively, as shown in FIG. 5C, the threshold value thDH for determining the rising edge of the waveform and the threshold value thDL for determining the falling edge are set, and the waveform PR of the pressure sensor is monitored. As described above, the rising timing of the detection signal of the pressure sensor is the timing immediately after the resin material fills the cavity. Therefore, it is possible to monitor the detected value Ddet of the pressure sensor, and determine that the time when this becomes equal to or greater than the threshold value thDH is the pressure control start timing (Ts2). The end timing of the pressure control is the timing before the mold 10 is opened, but it is judged from the change of the detected value Ddet or the value, for example, and the end timing (for example, the time when the detected value Ddet becomes less than the threshold thDL It is also possible to use Te 2). Thereby, time points Ts2 to Te2 can be set as the monitoring period.
The timing immediately after the resin material fills the cavity has a large rise width per unit time of the detection value Ddet. Therefore, if the threshold value thDH is set, various timings can be detected on the basis of that time point.
For example, the timing at which the resin material is filled can be detected to some extent accurately by detecting a point in time which is a predetermined time before the point in time at which the threshold value thDH is exceeded. That is, it is possible to specify the resin injection start time point by calculating back the time it takes to fill the resin material after the threshold value thDH is reached or more.
Therefore, it becomes possible to set the resin injection start time point in the molding cycle from the time point when the start time of the monitoring period becomes the threshold thDH or more. Thus, the resin injection start time can be specified only from the received detection signal data without receiving information from the molding control unit 12 at the resin injection start time.
The point at which it can be set as the reference may be any one if the range of fluctuation of the detection value Ddet per unit time is large. For example, it is the timing before opening the mold 10 and the detection value Ddet becomes less than the threshold thDL It is also possible to make the time point a reference.
Moreover, it is also possible to specify various time points in other measurement items using these reference time points.

  Also, the gate seal period can be set as the monitoring period. In this case, it is possible to grasp the specific time of the gate seal period by the mold 10 attached to the injection molding apparatus 2 or the resin material to be used. Therefore, only the threshold thDH for determining the rising of the waveform is set in advance, and the time when the gate seal period has elapsed by setting the time when the detection value Ddet of the pressure sensor becomes equal to or greater than the threshold thDH as the start timing of pressure control. Can be set as the end timing of the monitoring period.

In FIG. 5D, time points Ts3 to Te3 are periods in which the speed control of resin injection is performed in the injection molding apparatus 2. That is, it is a period during which the injection operation by the cylinder is controlled while monitoring the injection rate.
For example, the molding control unit 12 controls the speed of the injected resin until the resin fills the cavity of the mold 10, and performs control to switch to pressure control after the filling. In such a case, for resin injection speed control, it may be desirable to obtain an evaluation value of only the speed control period.
In such a case, for example, a threshold value thDH for determining the rising of the waveform is set, and the waveform PR of the pressure sensor is monitored. Considering the detection signal of the pressure sensor, the rising timing is the timing immediately after the resin material fills the cavity. It is because the resin is compressed by the injection of the resin after the filling and the pressure becomes high.
The detection value Ddet of the pressure sensor rises rapidly immediately after the filling. Therefore, it is possible to monitor the detected value Ddet of the pressure sensor and determine the point in time when this becomes equal to or higher than the threshold value thDH as the filling timing (point Te3), and set the period from point Ts3 to Te3 as the monitoring period.
The monitoring device 1 can acquire the value of the detection value Ddet of the period from the time point Ts3 to Te3 by acquiring the speed control period signal of the waveform of FIG. 5D from the shaping control unit 12 as one of the timing signals STM. .

Although three examples have been described above as measurement of a partial period, for example, one period of each of the above-described steps, a period of a state in which resin inflow is in progress, and removal of a molded article to the start of the next cycle. There are various possible target periods, such as the period.
Further, the monitoring period for each measurement item may be common or different. That is, as the monitoring period, a period in which an effective evaluation value can be calculated at the time of non-defective item determination can be set for each measurement item.

  When the setting process of the monitoring period is completed in step S102, the CPU 41 advances the process to step S103, and acquires setting information of the number of divisions. The numerical value of the division number is designated by an input operation via the user's input unit 46. The number of divisions can be specified in various ways, and the number of divisions input in the past may be specified, or the number of divisions may be fixed and set in advance.

After setting the monitoring period, in step S104, the CPU 41 performs processing of setting the monitoring timing based on the designated number of divisions.
The monitoring timing refers to timing for detecting a detection value Ddet used when performing non-defective item determination in mass production monitoring processing described later. The monitoring timing is set for each monitoring period for each measurement item.
For example, when the division number is designated as 4, in FIGS. 5A and 5C, the pressure sensor waveform PR with pressure control period Ts2 to Te2 as the monitoring period is divided into four regions X1, X2, and X3. Is set as the monitoring timing. Here, the monitoring period start points Ts2, X1, X2, X3 and the monitoring period end point Te2 are provided at equal intervals. The monitoring timing is similarly set not only for the resin pressure but also for other measurement items such as the resin flow velocity and the resin temperature.
Note that various modes can be considered for setting the monitoring timing. For example, it is also conceivable to set in advance a timing that is useful for performing non-defective item determination, and to divide the number of divisions to that timing with priority. In addition, it is possible to set the monitoring timing in the vicinity of the timing useful for the non-defective item determination.

In step S105, the CPU 41 extracts a group of detection signal data for each set monitoring timing using data of the detection signal at the time of non-defective product production acquired in step S101 as shown in FIG. 7A.
Then, the CPU 41 normalizes each detection signal data by obtaining an average value and a standard deviation for each monitoring timing of the extracted detection signal data group in step S106.
Thereafter, the CPU 41 calculates a correlation coefficient matrix from the normalized detection signal data group, and obtains an inverse matrix of the calculated correlation coefficient matrix. At this time, a reference value for determining a non-defective product is used. The reference value is calculated by {(measured value) − (mean value)} / (standard deviation).
The Mahalanobis distance (D value) of the data can be obtained by the above-mentioned inverse matrix and a quadratic form of arbitrary detection signal data.
In the MT method, the non-defective product judgment of a molded product is performed using a value (D2 value) obtained by squaring the calculated D value. This is a procedure for adjusting the root mean square of D value of the reference data group to around 1 regardless of the number of variables. The D2 value is a digitization of the deviation from the non-defective item data, and the closer the value is to 1, the better the item is.
Thus, unit space information in the present embodiment is set.

Thereafter, in step S107, the CPU 41 transmits the setting information of the unit space including the reference value to the monitoring device 1, thereby completing the unit space information setting process of FIG.

<6. Mass production monitoring process>
The mass production monitoring process according to the present embodiment will be described with reference to FIGS. 7 and 8.
In the mass production monitoring process, the non-defective item determination of the molded article is performed based on the unit space information set in the unit space information setting process. The mass production monitoring process is performed by the calculation unit 20 of the monitoring device 1.
In the following processing, for example, evaluation value (D2 value) calculation and determination are performed in real time during execution of one molding cycle of resin molding. In addition, the calculation unit 20 performs the process of FIG. 8 on detection signals of a plurality of input channels I1 to I8 in parallel for each measurement item (the actual process may be time division).

  First, in step S201 in FIG. 8, the calculation unit 20 acquires, from the monitoring device 1, data of detection signals for each measurement item in one non-defective molding cycle. Then, in step S202, the calculation unit 20 extracts a detection signal of monitoring timing in each measurement item for each product as shown in FIG. 7B.

  Thereafter, in step S203, the computing unit 20 extracts unit space information of non-defective items obtained from the computer device 4. Then, the calculation unit 20 calculates the Mahalanobis distance (D value) in the MT method as shown in FIG. 7B using the detection value Ddet detected at the monitoring timing in each of the extracted measurement items and the unit space information. Then, the D2 value is calculated by squaring the Mahalanobis distance.

Then, in step S205, the computing unit 20 performs quality determination using the D2 value. For example, by using threshold values thEH and thEL derived from unit space information, it is confirmed whether the D2 value is thEH ≧ D2 value ≧ thEL.
If this determination condition is satisfied, the process proceeds from step S205 to S206 as OK determination, and a notification signal SI of determination OK is transmitted to the forming control unit 12, and the computer apparatus 4 is notified of determination OK.
At this stage, the determination result information that the determination is OK is stored as log data together with identification information (information on the number of cycles) of the molding cycle this time.

  Thereafter, in step S207, the calculation unit 20 determines whether to continue monitoring, and in the case of continuing the process, the process proceeds to step S201, and the same process is performed thereafter. If not, the processing in FIG. 8 is ended.

On the other hand, if the determination condition of thEH ≧ D2 value ≧ thEL is not satisfied, the process proceeds from step S205 to S208 as an error determination, and transmits a determination error notification signal SI (alarm signal) to the forming control unit 12 and in step S209. , Notify the computer apparatus 4 of the determination error.
At this stage, determination result information that is a determination error (forming failure) may be stored as log data in the memory unit 24 together with identification information of the current forming cycle.

As described above, when the processing of the calculation unit 20 is performed, generation of the D2 value in the designated period in one molding cycle and quality determination based on the D2 value are performed.

<7. Summary and Modifications>
The computer device 4 according to the above-described embodiment is a monitoring device 1 for inputting detection signals of one or more measurement items by sensors (in-mold sensor 31 and in-injection sensor 32) provided in the injection molding device 2 The unit space information for determining the non-defective item is generated. In addition, the computer 4 determines the monitoring start time (Ts), and sets a predetermined period from the monitoring start time as a monitoring period (Ts to Te), and monitoring is performed based on the designated number of divisions. Monitoring of molded articles at the monitoring timing setting unit 41b for setting a plurality of monitoring timings (X1, X2, ..., Xn) in the period and at the monitoring timings (X1, X2, ..., Xn) set by the monitoring timing setting unit 41b And a unit space information setting unit 41c configured to set unit space information used for processing based on the acquired measurement item data at the time of non-defective product manufacturing.
That is, the monitoring timing is automatically set by setting at least the monitoring start time and the division number of the monitoring period. Further, at each monitoring timing, a reference value used for monitoring processing of a molded product is calculated based on the acquired measurement item data at the time of non-defective product manufacturing.
As a result, the operation of the molding cycle of the injection molding apparatus 2 and the preparation (setting) for determining the quality of the molded product can be more accurately and easily performed.

Further, the monitoring period setting unit 41a of the computer device 4 sets the gate seal period as a monitoring period.
When the detection signal used for determining the quality of the molded product is the resin pressure in the mold, the monitoring timing is preferably set during the gate seal period. Because the gate seal period is the period until the resin filled in the mold solidifies, it is a useful part for evaluating the quality of molded products, but the period after solidifying is not so meaningful It is because there is a case.
By setting the gate seal period suitable for the non-defective item determination of the molded item according to the property of the measurement item as the monitoring period, it is possible to set the monitoring timing to a point highly relevant to the molding process of the molded item. As a result, it is possible to perform the non-defective item determination with higher accuracy.

Further, the monitoring period setting unit 41a of the computer device 4 performs processing of specifying the monitoring start time (Ts) using the time when the detection signal reaches the set predetermined threshold (thDH).
Considering the detection signal of the pressure sensor, the rising timing is the timing immediately after the molding material is filled in the mold. Therefore, the timing of the rise is specified as the monitoring start time.
Thus, even if the user does not set a specific monitoring start time, it is possible to specify the monitoring start time only by setting the threshold. Therefore, the convenience of the user can be improved.

Further, the monitoring period setting unit 41a of the computer 4 performs processing of specifying a point in time a predetermined time before the point in time when the detection signal reaches the set predetermined threshold (thDH) as a monitoring start point (Ts). That is, monitoring of the molded article is started before a predetermined period before the rising timing of the detection signal of the pressure sensor.
The timing immediately after the resin material fills the cavity has a large rise width per unit time of the detection value Ddet. Therefore, it is possible to detect the timing at which the resin material is filled accurately to a certain extent.
Thus, the resin injection start time can be specified only from the received detection signal data without receiving information from the molding control unit 12 at the resin injection start time.

Further, the unit space information setting unit 41c of the computer device 4 performs a process of calculating the reference value using the value for each monitoring timing of the plurality of measurement items (S106 in FIG. 6).
In this way, unit space information is set in consideration of various measurement items and monitoring timings. Therefore, it is possible to improve the accuracy of the quality determination of the molded product.

Also, unit space information is considered to be information used to calculate a value obtained by squaring the Mahalanobis distance. That is, unit space information is set to replace the value of each multi-dimensional measurement item having different units with a unit as a common one dimension.
Thereby, in the quality determination of the molded product, even if all the measurement items satisfy the standard, it is possible to discover a product having a possibility of being a defective product as a whole of the molded product. Therefore, it is possible to further improve the accuracy of the quality determination of the molded product.

Furthermore, the present invention should not be limited to the above-described specific examples, and various modifications can be considered.
The configuration of the injection molding apparatus 2 can be considered in various ways. The configurations of the monitoring device 1 and the computer device 4 are the same.
The process of FIG. 6 may be performed by the calculation unit 20 of the monitoring device 1. In this case, the monitoring device 1 is the arithmetic processing device described in the claims.
The processing example of the CPU 41 of the computer device 4 shown in FIG. 6 is only an example, and various specific processing examples can be considered. The same applies to the processing example of the arithmetic unit 20 of the monitoring device 1 shown in FIG.
A variety of sensors (in-mold sensor 31 and in-injection sensor 32) mounted on the injection molding apparatus 2 are conceivable. That is, the monitoring device 1 measures the pressure of the resin material in the injection unit 11 and the mold 10 by the pressure sensor, and measures various detection signals other than the measurement of the molding material and the mold surface temperature based on the detection signal of the temperature sensor. Applicable to measurement. For example, flow velocity measurement of molding material based on detection signal of light sensor etc., flow front measurement based on detection signal of infrared sensor etc. (eg measurement of time until molding resin reaches predetermined position in cavity) position sensor etc. The present invention can also be suitably applied to detection signals of various sensors in the case of performing other measurements relating to injection molding, such as measurement of positional deviation between dies at the time of mold closing based on detection signals (measurement of mold opening).

<8. Program and storage medium>
The program according to the embodiment of the present invention is a program that causes the CPU 41 (an arithmetic processing unit such as a microcomputer) of the computer 4 to execute the functions as the monitoring period setting unit 41a, the monitoring timing setting unit 41b, and the unit space information setting unit 41c. It is.

  A program according to an embodiment of the present invention is an arithmetic processing unit that generates unit space information for non-defective item determination performed by a monitoring device that inputs detection signals of one or more measurement items by a sensor provided in an injection molding device. The process of specifying a monitoring start time and setting a predetermined period as the monitoring time from the monitoring start time, the process of setting a plurality of monitoring timings within the monitoring period based on the set number of divisions, and the setting It is a program program for executing processing of calculating unit space information used for monitoring processing of a molded product at monitoring timing based on the acquired measurement item data at the time of non-defective product manufacturing. That is, it is a program for executing the process of FIG.

Such a program facilitates the manufacture of the computer device 4 of the present embodiment.
Such a program can be stored in advance in a storage medium built in an apparatus such as the computer apparatus 4 or a ROM in a microcomputer having a CPU. Alternatively, it can be stored (stored) temporarily or permanently in a removable storage medium such as a semiconductor memory, a memory card, an optical disk, a magneto-optical disk, or a magnetic disk. Also, such removable storage media can be provided as so-called package software.
Further, such a program can be installed from a removable storage medium to a personal computer or the like, and can also be downloaded from a download site via a network such as a LAN or the Internet.

In addition, the computer apparatus 4 can be configured to have the function of the monitoring apparatus 1 by installing a program to be executed by the monitoring apparatus 1 according to such an embodiment in the computer apparatus 4.
For example, the dedicated amplifier 3 and the computer device 4 are directly connected by the connector. A detection signal of one or more input channels is supplied to the computer 4 via the dedicated amplifier 3. Then, when the software including the program is activated in the computer device 4, the computer device 4 executes the processing of FIG. 6. That is, the detection signal of the sensor (31, 32) is acquired, and the detection signal value (detection value Ddet) in the designated period which is a partial period within the period of one molding cycle by the injection molding apparatus 2 is used to The calculation is performed, and the evaluation value is used to obtain the determination result of the injection molding situation. Thus, the monitoring device 1 can be realized using the computer device 4 such as a personal computer.

  DESCRIPTION OF SYMBOLS 1 ... Monitoring apparatus, 2 ... Injection molding apparatus, 4 ... Computer apparatus, 41a ... Monitoring period setting part, 41b ... Monitoring timing setting part, 41c ... Unit space information setting part

Claims (8)

An arithmetic processing unit that generates unit space information for non-defective item determination, which is performed by a monitoring device that inputs detection signals of one or a plurality of measurement items by a sensor provided in an injection molding device.
A monitoring period setting unit that specifies a monitoring start time and sets a predetermined period as the monitoring time from the monitoring start time;
A monitoring timing setting unit configured to set a plurality of monitoring timings in the monitoring period based on the designated number of divisions;
A unit space information setting unit configured to set unit space information used for monitoring processing of a molded article at the monitoring timing set by the monitoring timing setting unit based on the acquired measurement item data at the time of non-defective product manufacturing;
Arithmetic processing device provided with The arithmetic processing unit according to claim 1, wherein the monitoring period setting unit sets a gate seal period as the monitoring period. The arithmetic processing unit according to claim 1, wherein the monitoring period setting unit specifies the monitoring start time point using a time point when the detection signal reaches a set predetermined threshold. The arithmetic processing unit according to claim 3, wherein the monitoring period setting unit specifies a point in time a predetermined time before the point in time at which the detection signal reaches the set predetermined threshold as the monitoring start point. The arithmetic processing device according to any one of claims 1 to 4, wherein the unit space information setting unit sets the unit space information based on values of a plurality of measurement items at the monitoring timing. The arithmetic processing unit according to claim 5, wherein the unit space information is information used to calculate a value obtained by squaring the Mahalanobis distance. An arithmetic processing unit for generating unit space information for non-defective item determination performed by a monitoring device that inputs detection signals of one or more measurement items by a sensor provided in an injection molding device,
A process of specifying a monitoring start time and setting a predetermined period as the monitoring time from the monitoring start time;
A process of setting a plurality of monitoring timings in the monitoring period based on the set number of divisions;
A process of calculating unit space information used for a monitoring process of a molded product at the set monitoring timing based on the acquired measurement item data at the time of non-defective product manufacturing;
Arithmetic method for performing. An arithmetic processing unit that generates unit space information for determination of non-defective items, which is performed by a monitoring device that inputs detection signals of one or more measurement items by a sensor provided in an injection molding device.
A process of specifying a monitoring start time and setting a predetermined period as the monitoring time from the monitoring start time;
A process of setting a plurality of monitoring timings in the monitoring period based on the set number of divisions;
A process of calculating unit space information used for a monitoring process of a molded product at the set monitoring timing based on the acquired measurement item data at the time of non-defective product manufacturing;
A program that runs

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