CN111093936A

CN111093936A - Arithmetic processing device, arithmetic method for arithmetic processing device, and program

Info

Publication number: CN111093936A
Application number: CN201880058735.6A
Authority: CN
Inventors: 岛野浩充; 鹤冈达也; 斋藤芳之; 野原康弘; 中西彻
Original assignee: Nidec Sankyo Corp; Futaba Corp
Current assignee: Futaba Corp; Nidec Instruments Corp
Priority date: 2017-09-26
Filing date: 2018-06-19
Publication date: 2020-05-01
Anticipated expiration: 2038-06-19
Also published as: CN111093936B; WO2019064734A1; JP2019059082A; JP6772119B2

Abstract

The invention sets unit space information for judging whether a formed product is good or not. An arithmetic processing device according to the present technology includes: a monitoring period setting unit that specifies a monitoring start time point and sets a predetermined period from the monitoring start time point as a monitoring period; a monitoring timing setting unit that sets a plurality of monitoring timings within the monitoring period based on the designated number of divisions; and a unit space information setting unit that sets unit space information for monitoring processing of the molded product at the monitoring timing set by the monitoring timing setting unit, based on the acquired measurement item data at the time of manufacturing the good product.

Description

Arithmetic processing device, arithmetic method for arithmetic processing device, and program

Technical Field

The present technology relates to an arithmetic processing device, an arithmetic method for the arithmetic processing device, and a program. More specifically, the present invention relates to a technical field of generating reference information for determining good product of a molded product manufactured by an injection molding apparatus.

Background

An injection molding quality monitoring system including a sensor and a monitoring device provided in an injection molding apparatus is known. The injection molding quality monitoring system can detect the movement of a molding material such as resin in a mold provided in an injection molding device by the sensor and output the detection result as a waveform to an information processing device such as a personal computer in real time. The injection molding quality monitoring system can monitor the measurement value based on the detection signal of the sensor and identify the defective product. As an injection molding quality monitoring system, for example, there is an injection molding quality monitoring system described in patent document 1.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2008-36975

Disclosure of Invention

Problems to be solved by the invention

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

When identifying defective products using such an injection molding quality monitoring system, a user needs to set a monitoring timing to be a monitoring target according to his or her own judgment. Therefore, if there is no experience to some extent with the injection molding quality monitoring system, it may be difficult to set a monitoring timing suitable for identifying defective products.

Therefore, an object of the present technology is to provide a function that enables a user with little experience in an injection molding quality monitoring system to easily set monitoring timing.

Means for solving the problems

An arithmetic processing device according to the present technology is an arithmetic processing device that generates unit space information for good product determination performed in a monitoring device that inputs detection signals of one or more measurement items from a sensor provided in an injection molding device, the arithmetic processing device including: a monitoring period setting unit that specifies a monitoring start time point and sets a predetermined period from the monitoring start time point as a monitoring period; a monitoring timing setting unit that sets a plurality of monitoring timings within the monitoring period based on the designated number of divisions; and a unit space information setting unit that sets unit space information for monitoring processing of the molded product at the monitoring timing set by the monitoring timing setting unit, based on the acquired measurement item data at the time of manufacturing the good product.

That is, the monitoring timing is automatically set by setting at least the monitoring start time and the number of divisions of the monitoring period. Further, for each monitoring timing, unit space information used in the process of determining the good product of the molded product is calculated based on the acquired measurement item data at the time of manufacturing the good product.

Here, the monitoring timing is timing for determining whether or not the molded product is good in the manufacturing process. The monitoring device acquires unit space information for good product determination at each monitoring timing in advance before mass production of molded products, and performs good product determination based on the unit space information.

The measurement item data is data of a measurement item used for the non-defective product determination.

The measurement items include various items required for evaluating the quality of the molded product, such as resin pressure, resin flow rate, resin temperature, and mold surface temperature.

In the arithmetic processing device according to the present technology, it is conceivable that the monitoring period setting unit sets a gate seal (gate seal) period as the monitoring period.

In the case where 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 to be in the gate sealing period.

This is because the gate sealing period is a period until the resin filled in the mold is cured. Therefore, the value of such a period is a value useful for evaluating the quality of a molded product, and the period after curing may be meaningless.

In the arithmetic processing device according to the present technology, it is possible to consider that the monitoring period setting unit specifies the monitoring start time using a time point at which the detection signal reaches the set predetermined threshold.

When the detection signal of the pressure sensor is taken into consideration, the timing of the rise is immediately after the mold is filled with the molding material. Therefore, the timing of this rise is determined as the monitoring start time point.

In the arithmetic processing device according to the present technology, it is conceivable that the monitoring period setting unit determines, as the monitoring start time, a time point that is earlier than a time point at which the detection signal reaches the set predetermined threshold by a predetermined time.

That is, the monitoring of the molded product is started a predetermined period of time earlier than the rising timing of the detection signal of the pressure sensor.

In the arithmetic processing device according to the present technology, it is conceivable that the unit space information setting unit sets the unit space information using a value for each of the monitoring timings for each of the plurality of measurement items.

This allows the unit space information to be set in consideration of various measurement items and monitoring timing.

In the arithmetic processing device according to the present technology, it is conceivable that the unit space information is information used for calculating a value obtained by squaring a mahalanobis distance.

That is, unit space information is set for replacing the value of each measurement item in a plurality of dimensions having different units with a unit of a common one-dimension.

An arithmetic method of an arithmetic processing device according to the present invention is an arithmetic method of generating unit space information for good product determination performed in a monitoring device in which a sensor provided in an injection molding device inputs a detection signal of one or more measurement items, the arithmetic processing device being configured to execute: a process of determining a monitoring start time point and setting a predetermined period from the monitoring start time point as a monitoring period; a process of setting a plurality of monitoring timings within the monitoring period based on the set number of divisions; and a process of calculating unit space information for monitoring processing of the molded product at the set monitoring timing based on the acquired measurement item data at the time of manufacturing the good product.

The program according to the present technology is a program for causing an arithmetic processing device to execute the processing of each step described above.

Effects of the invention

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

Drawings

Fig. 1 is an explanatory diagram of a quality monitoring system according to an embodiment.

Fig. 2 is an explanatory diagram of a display screen by management software according to the embodiment.

Fig. 3 is an explanatory diagram of the configuration of the monitoring device of the embodiment.

Fig. 4 is an explanatory diagram of the configuration of the computer device according to the embodiment.

Fig. 5 is an explanatory diagram of waveform data measured in the embodiment.

Fig. 6 is a flowchart of the unit space information setting process according to the embodiment.

Fig. 7 is an explanatory diagram of data used for good product determination in the embodiment.

Fig. 8 is a flowchart of the mass production monitoring process according to the embodiment.

Detailed Description

Hereinafter, the embodiments will be described in the following order.

<1. construction of quality monitoring System >

<2 > construction of monitoring device

<3 > construction of computer device

<4. overview of quality monitoring System >

<5. Unit space setting Process >

<6 > production volume monitoring processing

<7. summary and modification >

<8. program and storage Medium >

<1. construction of quality monitoring System >

Embodiments according to the present invention will be described below. First, an injection molding quality monitoring system 100 (also referred to simply as "quality monitoring system 100") including a monitoring device 1, an injection molding device 2, and a personal computer 4, which is an embodiment of the present invention, will be described.

Fig. 1 is a diagram showing an outline of the configuration of the quality monitoring system 100.

As shown in the drawing, 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").

As is generally known, the injection molding apparatus 2 is configured to have: a mold 10 disposed at a predetermined position; an injection unit 11 having a mechanism for injecting and filling a resin material into the mold 10; and a molding control unit 12 that controls the injection operation of the injection unit 11, the opening/closing operation of the mold 10, and the like, and controls a series of injection molding operations.

The mold 10 has, for example, an upper mold and a lower mold, and the upper mold is opened and closed with respect to the lower mold disposed in the molding bed by a mechanism provided in the injection unit 11. In a state where the upper mold is closed with respect to the lower mold, for example, a resin material is injected into a gate provided in the upper mold by an injection cylinder of the injection part 11, and a cavity in the mold 10 is filled with the resin material. After the filling, if a desired 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. The in-mold sensor 31 is, for example, a temperature sensor for detecting the temperature of the filled resin material, a pressure sensor for detecting the pressure of the resin material, or the like.

The structure and type of the mold 10 are not particularly limited, and various structures and types can be assumed.

The injection unit 11 is provided with a mechanism necessary for injection molding, such as an injection mechanism for injecting a resin material into the mold 10, a mold clamping mechanism, an injection cylinder mechanism, and an injection motor.

The injection unit 11 is provided with an in-injection-unit sensor 32 and a sensor amplifier 33. The injection section internal sensor 32 includes a temperature sensor for detecting the temperature of the resin material during the injection process, a pressure sensor for detecting the 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, for example, the cylinder structure, the structure of the mold clamping mechanism, the flow path structure, the nozzle structure, the heater arrangement, the motor arrangement, the material feeding mechanism, and the like are not particularly limited, and may be of any configuration and type.

The molding control Unit 12 is configured to include a microcomputer having, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and a CPU (Central Processing Unit).

The molding control unit 12 performs drive control of each unit of the injection unit 11. For example, injection motor control, mold stage operation control, mold opening/closing mechanism operation control, nozzle opening/closing mechanism operation control, heater control, material feed operation control, and the like are performed. Thereby, a series of injection molding actions are performed.

The detection signal S1 of the in-mold sensor 31 is converted into a voltage value by, for example, a dedicated amplifier 3 disposed separately from the injection molding apparatus 2. Then, the detection signal Vs1 converted into a voltage signal is supplied to the monitoring apparatus 1.

The detection signal S2 of the sensor 32 in the injection unit is converted into a voltage value by, for example, the sensor amplifier 33 provided in the injection unit 11. Then, the detection signal Vs2, which is a voltage signal converted, is supplied to the monitoring apparatus 1.

Although the two detection signals are represented as detection signals Vs1 and Vs2, the detection signal Vs1 is a generic term of the detection signal from the in-mold sensor 31, and the detection signal Vs2 is a generic term of the detection signal from the in-injection-section sensor 32. Of course, a case where a plurality of sensors are arranged as the in-mold sensor 31 and a case where a plurality of sensors are arranged as the in-injection-section sensor 32 are also assumed.

Therefore, the detection signals Vs1 and Vs2 are not detection signals indicating only a two-system, but indicating that both detection signals of the in-mold sensor 31 and the in-injection-section sensor 32 can be input to the monitoring device 1.

An n-channel input system is prepared in the monitoring apparatus 1, and detection signals of the n systems can be simultaneously input. Therefore, the detection signals Vs1 of the n sensors as the in-mold sensor 31 may be supplied to the monitoring device 1, or the detection signals Vs2 of the n sensors as the in-injection-section sensor 32 may be supplied to the monitoring device 1. Further, the detection signals Vs1, Vs2 may be single-system or multi-system detection signals of the in-mold sensor 31 and the in-injection-section sensor 32, respectively, distributed to the n channels and supplied to the monitoring apparatus 1.

What kind of detection signal is inputted to the monitoring device 1 may be determined as appropriate according to the actual injection molding device 2, the structure and type of the mold 10, the molded article, the number of mounted sensors, the contents of measurement and monitoring to be performed, and the like.

Although not shown, various sensors may be provided in peripheral devices of the injection molding apparatus 2, for example, a temperature controller for cooling, a vacuum extractor, and the like, and detection signals of these sensors are also assumed to be supplied to the monitoring apparatus 1.

The monitoring device 1 and the molding control unit 12 can perform various communications. Fig. 1 shows, as one of communications, a case where various timing signals STM are transmitted from the forming control unit 12 to the monitoring apparatus 1, and a case where the notification signal SI is transmitted from the monitoring apparatus 1 to the forming control unit 12.

One of the timing signals STM is a signal for notifying a start timing and an end timing of one cycle of injection molding, for example. The monitoring apparatus 1 can detect a molding period of one cycle of resin injection by one shot by the timing signal STM, and record and determine various detection signals during the period.

As another timing signal STM, a signal indicating the timing of the start/end of the mold clamping period, a signal indicating the timing of the process transition, a signal indicating the timing of switching the control system (speed control, pressure control), or the like can be considered as described later.

The notification signal SI from the monitoring apparatus 1 is a signal for notifying various kinds of detection information and results of determination information. For example, the signal is a signal such as an alarm notification when determining an abnormality such as a molding failure or a notification of the rising timing/falling timing of the detected signal waveform. The forming control unit 12 can perform various operation controls based on the notification signal SI of these contents.

The measurement results of the temperature, pressure, and the like obtained by the monitoring apparatus 1 can be read by the computer apparatus 4 connected to the monitoring apparatus 1 through 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.

The computer device 4 is provided with management software for managing measurement of various detection signals by the monitoring device 1. With this management software, an operator or the like can read the measurement result obtained by the monitoring apparatus 1 via the display of the computer apparatus 4.

In addition, the operator or the like can set various numerical values by setting using the management software.

Further, the measurement result can be recorded in a predetermined storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Disk) in the computer device 4.

Fig. 2 shows an example of the display contents of a management screen 90 presented on the screen of the computer device 4 by the management software. As shown in the drawing, the management screen 90 can display the measurement results of the detection signals from the various sensors by waveforms, and can display predetermined numerical values (for example, a peak value, an integrated value, a rise timing value, a fall timing value, and the like) of the respective detection signals. Further, an operator is prepared to input various settings.

<2 > construction of monitoring device

Fig. 3 shows an internal configuration of the monitoring apparatus 1.

The monitoring device 1 is provided with 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 the detection signals Vs1 and Vs2 in n channels. In the illustrated example, assuming eight-channel input, the input channels are represented 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.

Detection signals Vs1 and Vs2 are input to all or a part of the channels I1 to I8. That is, detection signals of one or more sensors provided in the injection molding apparatus 2 as the in-mold sensor 31 and the in-injection-section sensor 32 can be simultaneously input to the respective required channels.

The a/D converter 22 is capable of simultaneous input of the same number as the number of input channels. Thus, in the illustrated example, an eight channel input A/D converter.

The a/D converter 22 converts the input detection signals of the channels I1 to I8 into digital data corresponding to voltage values, and supplies the digital data to the buffer and IF unit 23.

The buffer and IF unit 23 collectively indicates a part for passing the detection signals of the channels I1 to I8 to the arithmetic unit 20 and for transmitting and receiving the communication data between the arithmetic unit 20 and the external devices (the computer device 4 and the forming control unit 12).

For example, digital data (a detection value Ddet described later) of a multi-channel detection signal output from the a/D converter 22 and input simultaneously is temporarily buffered by the buffer and IF unit 23, and is sequentially transmitted to the arithmetic unit 20 as detection information at each time point together with time information (a time value Tdet described later) of a sampling time point of the detection signal.

The notification signal SI from the arithmetic unit 20 is sent from the terminal TM2 to the molding control unit 12 by the buffer and IF unit 23. The various timing signals STM from the forming control unit 12 are temporarily received from the terminal TM1 into the buffer and IF unit 23, and are sequentially transmitted to the computing unit 20 together with the time information.

The arithmetic unit 20 communicates various information with the computer device 4 via the buffer and IF unit 23 via a communication path US connected to a terminal TM3 (for example, a LAN connector terminal).

The arithmetic unit 20 is constituted by a microcomputer having a ROM, a RAM, and a CPU, for example.

In the present embodiment, the arithmetic unit 20 performs a process of storing the detection signal value at each time point in each input channel input to the input unit 21 in the memory unit 24 as log data.

For example, processing is performed to store the value for each sample for the detection signals of the channels I1 to I8 converted into digital values in the a/D converter 22.

The calculation unit 20 calculates the 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.

Further, the calculation unit 20 performs a process of obtaining a determination result of the injection molding state using the calculated evaluation value. Further, the output process of the notification signal SI is performed in accordance with the determination process.

A specific example of the processing of the arithmetic unit 20 having these functions will be described later.

The memory unit 24 is collectively represented as a memory area usable by the arithmetic unit 20, for example, as a ROM, a work memory, a nonvolatile memory, or the like.

The memory unit 24 is used as a storage area of log data based on the processing of the arithmetic unit 20, for example. The memory unit 24 is used as a work area for various arithmetic processes. The memory unit 24 is also used as a storage area for programs for realizing various processes of the arithmetic unit 20.

<3 > construction of computer device

Fig. 4 shows an internal configuration of the computer device 4.

The CPU41 of the computer device 4 executes various processes in accordance with a program stored in the ROM42 or a program loaded from the storage unit 48 into the RAM 43. Data and the like necessary for the CPU41 to execute various processes are also stored in the RAM43 as appropriate.

The CPU41, ROM42, and RAM43 are connected to each other via a bus 44. An input/output interface 45 is also connected to the bus 44.

The input/output interface 45 is connected with: an input unit 46 including a keyboard, a mouse, a touch panel, and the like; an output unit 47 including a Display and a speaker, the Display including an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube), an organic el (electroluminescence) panel, and the like; a storage unit 48 configured by an HDD, a flash memory device, and the like; and a communication unit 49 that performs communication processing with the monitoring apparatus 1 via a communication path US connected to the terminal TM3 and communication via the internet.

In the present embodiment, the CPU41 has functions as a monitoring period setting unit 41a, a monitoring timing setting unit 41b, and a unit space information setting unit 41c, in particular.

The monitoring period setting unit 41a performs a process of specifying a monitoring start time point and setting a predetermined period from the specified monitoring start time point as a monitoring period.

The monitoring timing setting unit 41b performs a process of setting a plurality of monitoring timings within the monitoring period based on the set number of divisions.

Further, the unit space information setting unit 41c performs a process of setting the unit space information 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 good product.

A specific example of the processing of the CPU41 having these functions will be described later.

<4. overview of quality monitoring System >

An outline of the unit space setting processing in the quality monitoring system executed by the computer device 4 of the present embodiment will be described. The unit space setting processing of the present embodiment is the following processing: monitoring timing is set from within one molding cycle, and unit space information used for good product determination is set based on a detection signal for each monitoring timing.

An example of a waveform of a detection signal detected by a sensor, which is the in-mold sensor 31 or the in-injection-section sensor 32, is shown as a in fig. 5. The vertical axis represents the detection value (Ddet), and the horizontal axis represents time. For example, a solid line waveform PR is a detection value of the pressure sensor, and a broken line waveform TP is the mold internal temperature.

These are, for example, detection signal waveforms in one molding cycle corresponding to one shot of resin injection. The time points T0 to T1 are the period of one molding cycle. The single molding cycle includes, for example, the steps of closing the upper and lower molds of the mold 10, injecting the resin material into the mold 10 by the cylinder of the injection unit 11, holding pressure after filling, metering and cooling until molding and curing, opening the mold, and discharging the molded product.

In order to evaluate the detection signal of one molding cycle, an evaluation value obtained from the detection signal at each monitoring timing in the period T0 to T1 is usually required.

In the present embodiment, an MT (Maharanobis Taguchi) method is used as a method for calculating the evaluation value.

In the case where the manufacturing condition parameters of the equipment include various measurement items and measurement time points (monitoring timings), and they are in a relationship of mutual influence, it is preferable to monitor all items included in the manufacturing condition parameters in a comprehensive manner in consideration of the possibility that one item changes in an undesired direction.

In such a case, it is preferable to use the MT method as a method for making a plurality of items that affect each other into one dimension, taking into consideration the correlation in each dimension.

In the MT method, a value obtained by squaring the mahalanobis distance is used as an evaluation value indicating a degree of similarity to the item group serving as a reference. Details of the mahalanobis distance will be described later.

However, the meaning of the detection signal differs for each process. For example, the value of the detected value Ddet of the mold temperature during the closing of the mold 10 is useful for evaluating the quality of the molded product, but is not significant after the opening of the mold 10.

In this way, when evaluating the quality of the molded product, it is necessary to set an appropriate monitoring timing in the process. However, without some degree of experience in the quality monitoring system, it may be difficult to set a timing suitable for identifying defective products.

Therefore, in the present embodiment, when the quality monitoring system determines the quality of the molded product, the following processing is performed.

<5. Unit space information setting Process >

The unit space information setting process in the quality monitoring system according to the present embodiment will be described with reference to fig. 5 to 7.

The unit space setting process is as follows: the monitoring timing when the monitoring apparatus 1 executes the mass production monitoring process described later is determined, and the unit space information, which is information used for evaluating the quality of the molded product at the monitoring timing, is calculated. The unit space information setting process is performed by the CPU41 of the computer device 4.

First, in step S101 of fig. 6, the CPU41 acquires data of the detection signal for each measurement item in one molding cycle of a good product from the storage unit 48. The CPU41 acquires, for example, detection signal data of good products for 100 cycles. The detection signal data is data that the CPU41 has acquired from the monitoring apparatus 1 that has performed the measurement of data and stored in the storage unit 48.

As measurement items of the acquired detection signal data, various items required for evaluating the quality of the molded product, such as resin pressure, flow rate of resin, resin temperature, and mold surface temperature, can be considered.

Next, in step S102, the CPU41 performs a monitoring period setting process. That is, the CPU41 sets a partial period in one molding cycle as a monitoring period. This makes it possible to set a period useful for quality evaluation as a monitoring period for each measurement item.

The setting method of the monitoring period can be variously considered. For example, it is conceivable to set the mold clamping period from time Ts1 to Te1 shown in B in fig. 5 as the monitoring period. This period is a period during which a plurality of steps from mold closing 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 apparatus 1 acquires the detected value Ddet of the monitoring period at the time points Ts1 to Te1 by acquiring the mold clamping period signal having the waveform B in fig. 4 from the molding control unit 12 as one of the timing signals STM.

Alternatively, as shown in C in fig. 5, a threshold thDH for determining the rise of the waveform and a threshold thDL for determining the fall are set, and the waveform PR of the pressure sensor is monitored. As described above, the timing of the rise of the detection signal of the pressure sensor is the timing immediately after the cavity is filled with the resin material. Therefore, it is possible to monitor the detection value Ddet of the pressure sensor and determine the timing at which the detection value Ddet becomes equal to or greater than the threshold value thDH as the start timing of the pressure control (Ts 2). The timing of ending the pressure control is the timing before the mold 10 is opened, but the timing of ending the pressure control may be determined based on, for example, the value or the change in the value of the detection value Ddet, and the timing at which the detection value Ddet becomes equal to or less than the threshold value thDL may be set as the timing of ending (Te 2). Thus, the time points Ts2 to Te2 can be set as the monitoring period.

The amplitude of the rise per unit time of the detection value Ddet is large at the timing immediately after the cavity is filled with the resin material. Therefore, by setting the threshold thDH, various timings can be detected based on the time point.

For example, by detecting a time point that is earlier than a time point at which the threshold value thDH or more is reached by a predetermined time, the timing at which the resin material is filled can be detected with some degree of accuracy. That is, the resin injection start time can be determined by counting the time taken to fill the resin material from the time when the threshold value thDH or more is reached.

Therefore, the start time of the monitoring period can be set to the resin injection start time in the molding cycle, based on the time at which the threshold value thDH or more is reached. Thus, the resin injection start time can be determined based on only the received detection signal data without receiving information of the resin injection start time from the molding control unit 12.

The reference time may be set as long as the fluctuation width per unit time of the detection value Ddet is large, and for example, the reference time may be set to a time at which the detection value Ddet becomes equal to or less than the threshold value thDL before the mold 10 is opened.

Further, various time points in other measurement items can be specified using these time points as references.

Further, the gate sealing period may be set as the monitoring period. In this case, the specific time during the gate sealing period can be grasped by the mold 10 attached to the injection molding apparatus 2, the resin material used, and the like. Therefore, only the threshold value thDH at which the rise of the determination waveform is determined may be set in advance, and the timing at which the pressure control is started may be set as the time point at which the detection value Ddet of the pressure sensor becomes equal to or greater than the threshold value thDH, and the timing at which the gate sealing period has elapsed may be set as the timing at which the monitoring period ends.

In fig. 5D, time points Ts3 to Te3 are set as periods during which the injection molding apparatus 2 controls the speed of resin injection. That is, the injection speed is monitored and the injection operation by the cylinder is controlled.

For example, the molding control unit 12 performs control of the speed of resin injection before the cavity of the mold 10 is filled with resin, and performs control of switching to pressure control after filling. In this case, for the speed control of resin injection, it is sometimes desirable to obtain an evaluation value only during the speed control.

In this case, for example, a threshold thDH for determining the rise of the waveform is set, and the waveform PR of the pressure sensor is monitored. When the detection signal of the pressure sensor is taken into consideration, the timing of the rise of the detection signal is immediately after the cavity is filled with the resin material. This is because the resin is further injected after filling, and the resin is compressed and the pressure becomes high.

The detection value Ddet of the pressure sensor rises sharply immediately after the filling. Therefore, the time point at which the detected value Ddet of the pressure sensor becomes equal to or greater than the threshold thDH is determined as the full timing (time point Te3), and the period from time point Ts3 to Te3 can be set as the monitoring period.

The monitoring apparatus 1 can acquire the value of the detection value Ddet during the period from the time point Ts3 to the time point Te3 by acquiring the velocity control period signal of the waveform D in fig. 5 from the forming control unit 12 as one of the timing signals STM.

While three examples have been described above as the measurement of the partial period, various target periods such as a period of one of the above-described steps, a period in a state in which the resin is flowing, a period from the removal of the molded product to the start of the next cycle, and the like can be considered.

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 when a good product is determined can be set for each measurement item.

When the process of setting the monitoring period is completed in step S102, the CPU41 advances the process to step S103 to acquire setting information of the number of divisions. The numerical value of the division number is designated by the user through an input operation of the input unit 46. The number of divisions may be designated by various methods, and the number of divisions input in the past may be designated, or may be set in advance.

After the monitoring period is set, in step S104, the CPU41 performs a process of setting a monitoring timing based on the designated number of divisions.

The monitoring timing is a timing to detect the detection value Ddet used when the good product determination is performed in the mass production monitoring process described later. The monitoring timing is set for each monitoring period of the measurement items.

For example, when the division number is designated as 4, in a in fig. 5 and C in fig. 5, in the waveform PR of the pressure sensor in which the pressure control periods Ts2 to Te2 are set as the monitoring period, X1, X2, and X3 are set as monitoring timings so as to be divided into four regions. Here, the monitoring period start time points Ts2, X1, X2, X3, and the monitoring period end time point Te2 are set at equal intervals. The monitoring timing is similarly set not only for the resin pressure but also for other measurement items such as the flow rate of the resin, the resin temperature, and the like.

In addition, various modes can be considered for setting the monitoring timing. For example, it is conceivable to set a timing useful for the determination of good product in advance and assign the division number to the timing preferentially. In addition, the monitoring timing can be set to be important near the timing useful for the good product determination.

In step S105, the CPU41 extracts a detection signal data set for each set monitoring timing using the data of the detection signals at the time of good product manufacturing acquired in step S101 as shown in a in fig. 7.

Then, in step S106, the CPU41 calculates the average value or standard deviation for each monitoring timing of the extracted detection signal data group, thereby normalizing the detection signal data.

Then, the CPU41 calculates a correlation coefficient matrix from the normalized detection signal data group, and obtains the inverse matrix of the calculated correlation coefficient matrix. At this time, a reference value for determination as a good product is used. The reference value is calculated by [ (measured value) - (average) ]/(standard deviation).

From the inverse matrix and the quadratic form of the arbitrary detection signal data, the mahalanobis distance (D value) of the data can be obtained.

In the MT method, a good product of the manufactured molded product is determined using a value (D2 value) obtained by squaring the calculated D value. This is a measure for adjusting the mean square of the D value of the reference data group to about 1 regardless of the number of variables. The D2 value is a numerical value representing the deviation from the good product data, and a good product is represented as the numerical value approaches 1.

The unit space information in the present embodiment is set in this manner.

Thereafter, in step S107, the CPU41 transmits the setting information of the unit space including the reference value to the monitoring apparatus 1, thereby completing the unit space information setting process of fig. 6.

<6 > production volume monitoring processing

The mass production monitoring process in the present embodiment will be described with reference to fig. 7 and 8.

The mass production monitoring process determines the good product of the molded product 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.

The following processing is an example in which the evaluation value (D2 value) calculation and determination are performed in real time during one molding cycle of resin molding, for example. The processing in fig. 8 is performed in parallel (may be performed in time division as actual processing) for each measurement item for the detection signals of the plurality of input channels I1 to I8 by the arithmetic unit 20.

First, in step S201 in fig. 8, the arithmetic unit 20 acquires data of a detection signal for each measurement item in one molding cycle of a good product from the monitoring device 1. Then, in step S202, the arithmetic section 20 extracts detection signals of monitoring timings in the respective measurement items for each product as shown by B in fig. 7.

Thereafter, in step S203, the arithmetic unit 20 extracts the unit space information of the good product acquired from the computer device 4. Then, the arithmetic unit 20 calculates the mahalanobis distance (D value) in the MT method as shown in B in fig. 7, using the detected value Ddet detected at the monitoring timing in each of the extracted measurement items and the unit space information. The D2 value is then calculated by squaring the mahalanobis distance.

Then, in step S205, the arithmetic unit 20 performs a good/bad determination using the D2 value. For example, using the thresholds threh, thll derived from the unit space information, it is confirmed whether the value of D2 satisfies the condition that threh ≧ D2 value ≧ thll.

If the determination condition is satisfied, the flow proceeds from step S205 to step S206 as an OK determination, and the notification signal SI of the OK determination is transmitted to the forming control unit 12, and the OK determination is notified to the computer device 4.

At this stage, the determination result information such as the determination OK is stored as log data together with the identification information of the current molding cycle (information of the several cycles).

Thereafter, in step S207, the arithmetic unit 20 determines whether or not to continue monitoring, and if so, advances the process to step S201, and the same process is performed below. If not continued, the processing of fig. 8 is ended.

On the other hand, if the determination condition of the value of thEH ≧ D2 ≧ theL is not satisfied, the process proceeds from step S205 to step S208 as an error determination, and a notification signal SI (alarm signal) for determining an error is transmitted to the forming control unit 12, and in step S209, the determination error is notified to the computer device 4.

At this stage, determination result information such as a determination error (molding failure) may be stored in the memory unit 24 as log data together with identification information of the molding cycle of this time.

By performing the processing of the arithmetic unit 20 as described above, the D2 value is generated in the predetermined period within one molding cycle, and the quality determination based on the D2 value is performed.

<7. summary and modification >

The computer device 4 of the above embodiment generates unit space information for good product determination performed in the monitoring device 1, and the monitoring device 1 inputs detection signals of one or more measurement items from the sensors (the in-mold sensor 31 and the injection-section sensor 32) provided in the injection molding device 2. Further, the computer device 4 includes: a monitoring period setting unit 41a that specifies a monitoring start time point (Ts) and sets a predetermined period from the monitoring start time point as monitoring periods (Ts to Te); a monitoring timing setting unit 41b that sets a plurality of monitoring timings (X1, X2, … …, Xn) within the monitoring period based on the designated number of divisions; and a unit space information setting unit 41c that sets unit space information for monitoring processing of the molded product at the monitoring timing (X1, X2, … …, Xn) set by the monitoring timing setting unit 41b, based on the acquired measurement item data at the time of manufacturing the good product.

That is, the monitoring timing is automatically set by setting at least the monitoring start time and the number of divisions of the monitoring period. Further, based on the acquired measurement item data at the time of manufacturing good products, reference values used for monitoring processing of the molded products are calculated for each monitoring timing.

This makes it possible to more accurately and easily prepare (set) the operation of the molding cycle of the injection molding apparatus 2 and the quality determination of the molded product.

The monitoring period setting unit 41a of the computer device 4 performs a process of setting the gate sealing period to the monitoring period.

In the case where 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 to be in the gate sealing period. This is because the gate sealing period is a period before the resin filled in the mold is cured, and therefore is a useful part for evaluating the quality of the molded product, and the period after curing may not be significant.

By setting the gate sealing period suitable for the determination of good product quality of the molded product according to the properties of the measurement items as the monitoring period, the timing point having high correlation with the molding process of the molded product can be set as the monitoring timing. This enables high-precision good product determination.

The monitoring period setting unit 41a of the computer device 4 performs a process of determining a monitoring start time point (Ts) using a time point at which the detection signal reaches the set predetermined threshold value (thDH).

When the detection signal of the pressure sensor is taken into consideration, the timing of rising of the detection information is the timing immediately after the mold is filled with the molding material. Therefore, the timing of this rise is determined as the monitoring start time point.

Thus, even if the user does not set a specific monitoring start time, the monitoring start time can be determined only by setting the threshold value in advance. Therefore, the convenience of the user can be improved.

The monitoring period setting unit 41a of the computer device 4 performs a process of determining a time point that is a predetermined time earlier than a time point at which the detection signal reaches the set predetermined threshold value (thDH) as a monitoring start time point (Ts). That is, the monitoring of the molded product is started a predetermined period of time earlier than the rising timing of the detection signal of the pressure sensor.

At the time immediately after the cavity is filled with the resin material, the rise per unit time of the detection value Ddet is large. Therefore, the timing of filling with the resin material can be detected to some extent accurately.

Thus, the resin injection start time can be determined based on only the received detection signal data without receiving information of the resin injection start time from the molding control unit 12.

The unit space information setting unit 41c of the computer device 4 performs a process of calculating a reference value using the value for each monitoring timing of each of the plurality of measurement items (step S106 in fig. 6).

This allows the unit space information to be set in consideration of various measurement items and monitoring timing. Therefore, the accuracy of the quality determination of the molded product can be improved.

It is also conceivable that the unit space information is used to calculate a value obtained by squaring the mahalanobis distance. That is, unit space information is set for replacing the value of each measurement item in a plurality of dimensions having different units with a unit of a common one-dimension.

Thus, in the determination of the quality of the molded product, it is possible to find a product that may have defective products as a whole molded product even if all the measurement items satisfy the criteria. Therefore, the accuracy of the quality determination of the molded product can be further improved.

The present invention is not limited to the specific examples described above, and various modifications are possible.

The configuration of the injection molding apparatus 2 can be variously considered. The monitoring apparatus 1 and the computer apparatus 4 have the same configuration.

The processing of fig. 6 may be performed by the arithmetic unit 20 of the monitoring apparatus 1. In this case, the monitoring device 1 is an arithmetic processing device as claimed.

The processing example of the CPU41 of the computer device 4 shown in fig. 6 is merely an example, and specific processing examples can be variously considered. The same applies to the processing example of the arithmetic unit 20 of the monitoring device 1 shown in fig. 8.

Various sensors (in-mold sensor 31 and injection section sensor 32) mounted on the injection molding apparatus 2 can be considered. That is, the monitoring device 1 can be applied to the measurement of the pressure of the resin material in the injection part 11 and the mold 10 by the pressure sensor, the measurement of the molding material and the mold surface temperature based on the detection signal of the temperature sensor, and the measurement of various detection signals. For example, the present invention can be suitably applied to detection signals of various sensors for performing other measurements related to injection molding, such as measurement of a flow rate of a molding material based on a detection signal of an optical sensor or the like, measurement of a flow front based on a detection signal of an infrared sensor or the like (for example, measurement of a time until a molded resin reaches a predetermined position in a mold cavity), measurement of a positional displacement amount between molds at the time of mold closing based on a detection signal of a position sensor or the like (measurement of an open modulus), and the like.

<8. program and storage Medium >

The program according to the embodiment of the present invention is a program for causing the CPU41 (an arithmetic processing device such as a microcomputer) in the computer device 4 to execute the functions of the monitoring period setting unit 41a, the monitoring timing setting unit 41b, and the unit space information setting unit 41 c.

The program of the embodiment is a program for causing an arithmetic processing device for generating unit space information for good product determination, which is performed in a monitoring device for inputting a detection signal of one or more measurement items by a sensor provided in an injection molding device, to execute: a process of determining a monitoring start time point and setting a predetermined period from the monitoring start time point as a monitoring period; a process of setting a plurality of monitoring timings within the monitoring period based on the designated number of divisions; and a process of calculating unit space information for monitoring processing of the molded product at the set monitoring timing based on the acquired measurement item data at the time of manufacturing the good product. That is, it is a program for causing the arithmetic processing device to execute the processing of fig. 6.

By such a program, the computer device 4 of the present embodiment can be easily manufactured.

Such a program can be stored in advance in a storage medium built in a device such as the computer device 4, a ROM in a microcomputer having a CPU, or the like. Alternatively, the information may be temporarily or permanently stored (stored) in a removable storage medium such as a semiconductor memory, a memory card, an optical disc, a magneto-optical disc, or a magnetic disk. In addition, such a removable storage medium may be provided as so-called package software.

Such a program can be installed from a portable storage medium to a personal computer or the like, and can be downloaded from a download site via a network such as a LAN or the internet.

Further, by installing a program to be executed by the monitoring apparatus 1 according to the embodiment in the computer apparatus 4, the computer apparatus 4 can also have the function of the monitoring apparatus 1.

The dedicated amplifier 3 and the computer device 4 are directly connected by a connector, for example. The detection signals of one or more input channels are supplied to the computer device 4 via a dedicated amplifier 3. Then, software including the program is started in the computer device 4, whereby the processing of fig. 6 is executed in the computer device 4. That is, the detection signals of the sensors (31, 32) are acquired, the evaluation value is calculated using the detection signal value (detection value Ddet) in a predetermined period set based on a partial period within a period of one molding cycle of the injection molding apparatus 2, and the processing for obtaining the determination result of the injection molding state using the evaluation value is performed. This enables the monitoring apparatus 1 to be implemented using the computer apparatus 4 such as a personal computer.

Description of the reference numerals

1: a monitoring device; 2: an injection molding device; 4: a computer device; 41 a: a monitoring period setting unit; 41 b: a monitoring timing setting unit; 41 c: a unit space information setting unit.

Claims

1. An arithmetic processing device for generating unit space information for good product determination performed by a monitoring device to which a detection signal of one or more measurement items is input from a sensor provided in an injection molding device, the arithmetic processing device comprising:

a monitoring period setting unit that specifies a monitoring start time point and sets a predetermined period from the monitoring start time point as a monitoring period;

a monitoring timing setting unit that sets a plurality of monitoring timings within the monitoring period based on the designated number of divisions; and

and a unit space information setting unit that sets unit space information for monitoring processing of the molded product at the monitoring timing set by the monitoring timing setting unit, based on the acquired measurement item data at the time of manufacturing the good product.

2. The arithmetic processing device according to claim 1, wherein the monitoring period setting unit sets a gate sealing period as the monitoring period.

3. The arithmetic processing device according to claim 1 or 2, wherein the monitoring period setting unit determines the monitoring start time point using a time point at which the detection signal reaches a set predetermined threshold value.

4. The arithmetic processing device according to claim 3, wherein the monitoring period setting unit determines, as the monitoring start time point, a time point that is earlier by a predetermined time than a time point at which the detection signal reaches a predetermined threshold value that is set.

5. 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 a value of each of the plurality of measurement items at the monitoring timing.

6. The arithmetic processing device according to claim 5, wherein the unit space information is information used for calculating a value obtained by squaring a mahalanobis distance.

7. An arithmetic method for generating unit space information for good product determination in a monitoring device in which a sensor provided in an injection molding device inputs a detection signal of one or more measurement items, the arithmetic processing device being configured to execute:

a process of determining a monitoring start time point and setting a predetermined period from the monitoring start time point as a monitoring period;

a process of setting a plurality of monitoring timings within the monitoring period based on the set number of divisions; and

and a process of calculating unit space information to be used for the monitoring process of the molded product at the set monitoring timing based on the acquired measurement item data at the time of manufacturing the good product.

8. A program for causing an arithmetic processing device for generating unit space information for good product determination, which is performed in a monitoring device for inputting detection signals of one or more measurement items by a sensor provided in an injection molding device, to execute: