JPH06190887A - Molding machine with function of analyzing cause of nonconformity of molded product - Google Patents

Abstract

PURPOSE:To provide a molding machine which can automatically identify the cause of nonconformity when it occurs by conducting branching selection treatment by judgment treatment when the nonconformity of a molded product is input to specify and by identifying the most probable cause of the nonconformity. CONSTITUTION:A nonconformity cause judgment part 35, when the nonconformity of a molded product is input to specify, conducts judgment treatment on the basis of measured values of a monitoring item having the highest priority for the judgment of the cause of the nonconformity to conduct branching selection treatment corresponding to the result of the judgment. Judgment treatment based on the measured values of other items in the selected branching is conducted as required, and the branching selection treatment corresponding to the judgment result is repeated as many times as required, so that the most probable cause of the nonconformity is identified by the selection treatment. Information on the identified cause of the nonconformity is transmitted to a display control part 36, through which the cause of the nonconformity and measures against it are displayed on a display 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding machine having a molded product defect cause analysis function, and in particular, a defective phenomenon occurs by utilizing monitor data which is an actual measurement value of operation data taken in during molding operation. In this case, the present invention relates to a molding machine such as an injection molding machine, a foam molding machine, a die casting machine or the like, which is capable of automatically identifying a failure cause item that is a factor causing the failure phenomenon.

[0002]

2. Description of the Related Art Recent molding machines, such as injection molding machines, are designed to carry out continuous molding operation based on preset molding operation condition values under the control of a microcomputer (hereinafter referred to as "microcomputer"). In addition, various measurement data screens, various operating condition setting screens, various statistical processing data screens, various alarm message screens, etc. can be displayed on a display device such as a color CRT display attached to the machine (injection molding machine) to enable operation. It is designed to support monitoring and condition setting.

Further, actually measured values of a large number of predetermined monitor items during continuous molding operation are appropriately measured and arithmetically processed and stored in a predetermined storage area, and each measured monitor data (actually measured operation data) is previously stored. Compare with the set upper and lower limits (allowable range), and if it is outside the allowable range, instruct the product take-out robot to handle the molded product of the shot as a defective product, or monitor outside the allowable range. There are injection molding machines on the market that are designed to stop the machines (injection molding machines) in an emergency according to the degree of importance in terms of item safety and the level outside the allowable range.

By the way, in the conventional microcomputer-controlled injection molding machine, when a defective product (“burr”, “sink”, “silver”, “bubble”, etc.) occurs, this defective product (defective) There is no known one that has a function of automatically identifying the cause (cause) of occurrence of a phenomenon. When such a defective molded product occurs, the injection molding machine configured to display a countermeasure method for dealing with the defective on the display device as a defective countermeasure screen in the form of a list as shown in FIG. As is well known, on this defect countermeasure screen, a plurality of defect causes for one defect phenomenon and a countermeasure method for each defect cause are simply listed and displayed in no particular order.

[0005]

[Problems to be solved by the invention] "burrs" on molded products,
When defects such as “sinks”, “silver”, and “bubbles” occur, these defect phenomena are visually recognized relatively easily by the operator (machine operator), and the defect phenomena are easily identified. . However, in injection molding, there is almost no one-to-one correspondence between the defective phenomenon and the cause (cause), and it is general that a plurality of causes (cause) are considered for one defective phenomenon. . Conventionally, when such a defective molded product occurs, an experienced worker relies on his experience and intuition to identify the cause (cause) of the defective molded product and take countermeasures. It is considerably difficult for even a seasoned worker to identify, and there is a problem that it takes time and effort to retry the defect countermeasure.

As described above, the conventional defect countermeasure screen for displaying a plurality of defect causes for one defect phenomenon and a countermeasure method for each defect cause in the form of a list is as follows:
Since the causes of defects and the countermeasures against each cause of defects are simply listed and arranged in no particular order, they can only be used in a textual manner. The reality is that it relied on the experience and intuition of the workers.

Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art,
It is an object of the present invention to provide a molding machine having a function of automatically identifying the cause of a defective phenomenon when the defective phenomenon occurs.

[0008]

In order to achieve the above-mentioned object, the present invention executes a molding operation based on a preset molding operation condition value, and actually measures a number of predetermined monitor items during the molding operation. When a defective phenomenon of a molded product is input and designated by the operator in a molding machine that has the function of storing values, the monitor item with the highest priority (importance) that should be judged for the defective cause of the defective phenomenon is displayed. A determination process based on the actual measurement value is performed, and a selection process is performed by branching (division) according to the determination result. After that, if necessary, another branch branch (selection branch) is selected in the above process. The determination process based on the measured values of the monitor items is performed, and the selection process by branching (division) according to the determination result is further repeated as many times as necessary. Identify the cause of failure would highly potential, the identified cause of failure to display on a display device with a countermeasure method is.

[0009]

When the operator inputs and designates, for example, "short shot" as a defective phenomenon of the molded product in an interactive manner with a predetermined mode screen (for example, a defect countermeasure screen) on the display device, the defective cause determination unit of the microcomputer. Is based on a failure cause analysis program created in advance, and is closely related to the failure phenomenon of "short circuit" from the measured value storage unit that stores a large number of operating condition measured values (monitor data) during molding operation. As the monitor item data with the highest priority (importance) to be judged, monitor data related to the cushion amount is extracted, and this cushion amount (stroke corresponding to the amount of resin remaining on the screw tip side at the time of injection completion) is an appropriate amount. It is determined whether or not

If the cushion amount is less than an appropriate amount value (for example, 3 to 5 mm), the defect cause determining unit determines
It was identified that the cause (cause) of the “short” was insufficient measurement of the amount of molten resin during the kneading / plasticizing / measuring process (during the charging process) (insufficient amount of molten resin stored at the screw tip side). When the cushion amount is larger than the appropriate amount value, the cause (cause) of the "short circuit" is that the holding pressure switching position (the screw stroke position for switching from primary injection to holding pressure) during the injection stroke is defective. If the cushion amount is appropriate, the determination process for identifying the cause (cause) of the occurrence of the “short” from another viewpoint is performed.

That is, if the cushion amount is appropriate in the above-described first-stage determination processing, the defect cause determination unit extracts monitor data relating to the pressure holding switching position from the measured value storage unit to determine the cushion amount and the pressure holding amount. It is determined whether or not the relationship with the switching position is proper. If there is an abnormality such that the cushion amount comes behind the holding pressure switching position (normally the holding pressure switching position comes slightly before the cushion amount), the cause of the "short circuit" ( Cause)
Was identified as a defective holding pressure switching position during the injection stroke, and if the relationship between the cushion amount and the holding pressure switching position was appropriate, the cause of the “short circuit” (cause)
However, it is specified that the filling pressure was insufficient during the injection stroke.

In this way, the cause of the defect phenomenon of "short circuit" is automatically specified by the determination process using the monitor data, and the specified cause of "short circuit" is displayed on the defect countermeasure screen of the display device. The countermeasure method corresponding to this cause is displayed.

Similarly, when another defect phenomenon is input and designated by the operator, the defect cause determining unit executes the determination process based on the monitor item data to be determined for the defect phenomenon, and the defect phenomenon is detected. The cause is automatically identified, and the cause of the identified defect phenomenon and the countermeasure method corresponding to this cause are displayed on the defect countermeasure screen of the display device.

By doing so, the injection molding machine itself automatically executes a job for identifying the cause (cause) of the time-consuming defective product, which has conventionally relied on the experience and intuition of an experienced worker. Since it is carried out in a timely manner, defect countermeasures can be taken reliably and quickly.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory diagram showing a main configuration of an injection molding machine according to this embodiment, FIG. 2 is an explanatory diagram showing an example of a defect countermeasure screen according to this embodiment, and FIGS. 3 and 4 are causes of defects according to this embodiment. It is explanatory drawing which shows the flow of a process in a determination part.

In FIG. 1, reference numeral 1 denotes a mold opening / closing mechanism system, which includes a fixed die plate 2 to which a fixed mold 3 is attached, a support plate 4 to which a mold clamping cylinder 5 is attached, and a movable mold 7.
And a movable die plate 6 which is driven by a mold clamping cylinder 5 via a toggle link mechanism 8 and the like.

Reference numeral 10 denotes an injection mechanism system, which is a heating cylinder 11 having a known screw built therein, a hopper 12 for charging and supplying a resin material into the heating cylinder 11 (a rear portion of the screw), and a heating cylinder 11 which is attached to the front end side. Nozzle 1 that comes into close contact with the resin injection hole of the fixed mold 3
3, a screw rotation drive source 14, a forward drive source (not shown), a heater 15 wound around the heating cylinder 11 and the nozzle 13, and the like.

In FIG. 1, 20 is a microcomputer (microcomputer) that controls the operation and display control of the entire machine (injection molding machine), and 21 is a sensor group composed of many sensors provided in each part of the machine. , 22 is a driver group composed of a large number of driver circuits for driving and controlling a large number of drive sources arranged in each part of the machine, 23 is a key input device arranged in the front part of the machine, and 24 is the above For example, a color C arranged adjacent to the key input device 23
The display device includes an RT display, a color LCD, and the like.

The microcomputer 20 described above is used for kneading, plasticizing,
Control of the entire molding process such as metering operation (charge operation), injection operation (primary injection and pressure holding operation), mold opening / closing operation, ejecting operation, product (molded product) removal / sorting operation by the product removal robot, and actual measurement data Calculation / storing process of
Various processing such as monitoring / determination processing using monitor data, calculation / determination processing such as determination analysis processing of a cause of defective molded product, and display control processing of an output image of the display device 24 are executed. The microcomputer 20 actually comprises various I / O interfaces, ROM, RAM, MPU, etc., and executes various processes by various programs created in advance. The following description will be made on the assumption that the setting storage unit 31, the molding process control unit 32, the measured value storage unit 33, the monitor data monitoring processing unit 34, the defect cause determination unit 35, the display control unit 36 and the like are provided.

In the molding condition setting storage unit 31, various operating condition values input by the key input device 23 or the like are stored in a rewritable form. The operating condition values include, for example, the relationship between the screw position and the screw rotation speed during the kneading / plasticizing / measuring (charging) process, the screw retreat speed, and the back pressure, suck back control conditions, switching of the holding pressure from the start of injection. Injection speed conditions and primary injection pressure conditions, holding pressure switching conditions, holding pressure conditions from the holding pressure switching time to the holding pressure end, mold closing (mold clamping) stroke and speed control conditions, and mold clamping force, mold The opening stroke and speed control conditions, the eject control conditions, the control conditions of the product take-out robot, the heater temperature of each part, the cooling temperature of each part, and the like are included.

The molding process control unit 32 is based on a molding process control program created in advance and setting condition values stored in the molding condition setting storage unit 31, and the sensor group 21 arranged in each unit of the machine. The driver group 22 (motor driver) is referred to while referring to the data from the actual measurement value storage unit 33 that fetches the measurement information from (position sensor, pressure sensor, temperature sensor, etc.) in real time and the timing information from the clock built in itself. , A hydraulic pressure control valve driver, a cooling water control valve driver, a heater driver, etc.) to appropriately drive and control a corresponding drive source to execute a series of molding steps.

In the actual measurement value storage unit 33, all actual measurement data (monitor data) of preset monitor items during continuous automatic operation are appropriately converted over a predetermined number of consecutive shots as necessary. It is applied, captured, and stored. As the monitor items to be imported,
Time monitoring item, position monitoring item, rotation speed monitoring item,
Speed monitoring items, pressure monitoring items, temperature monitoring items, electric power monitoring items, and the like are included, and the important items of the molding operation condition setting items described above are almost included.

The monitor data monitoring processing section 34 is provided with an allowable range table which stores the upper limit value and the lower limit value preset for each of the above-mentioned many monitor items. Then, the monitor data monitoring processing unit 34 determines whether or not the actual measurement data of the latest shot transferred from the actual measurement value storage unit 33 is within the allowable range by referring to the content of the allowable range table, When it is determined that the product is out of the allowable range, a signal corresponding to the level is sent to the molding process control unit 32 so that the product of the latest shot is transferred to the defective product storage by the product picking robot, or the machine is urgently needed. Stop. Furthermore, when the measured data of the latest shot is determined to be outside the allowable range, the monitor data monitoring processing unit 34 causes the display control unit 36 to display an alarm message screen as needed.

The defect cause determining section 35, in a state where a predetermined defect countermeasure screen is called on the display device 24, allows the operator to select one of the molded product defect phenomena in the defect item selection field on the defect countermeasure screen. By specifying in accordance with a failure cause analysis program created in advance, the measured values (monitor data) of predetermined items necessary for analyzing the cause of the failure are extracted from the measured value storage unit 33, and this monitor data is extracted. Execute the analysis process of the cause of the defect used. That is,
The defect cause determination unit 35 performs a determination process based on the actual measurement value of the monitor item having the highest priority (importance) to be determined for the input and designated defect phenomenon, and branches according to the determination result. First, a first selection process, which is a (classification) process, is performed. If the cause of the defect can be specified in the branch branch (selected branch) selected by the first selection process, the cause of failure is specified and the process ends, and the branch branch selected by the first selection process ( If the cause of the failure cannot be identified in the selected branch), the selected branch branch (selected branch) is subjected to the judgment processing based on the actual measurement values of other monitor items, and the branching (sorting) is performed according to the judgment result. A second selection process, which is a process, is performed. If the cause of the defect can be specified in the branch branch (selected branch) selected by the second selection process, the cause of failure is specified and the process ends, and the branch branch selected by the second selection process ( When the cause of the failure cannot be specified in the selected branch, the judgment processing based on the actual measured values of other monitor items is further performed in the selected branch (selected branch), and the branching (sorting) according to the judgment result is performed. ) Perform the third selection process as a process. The selection process is repeated a necessary number of times until the cause of the defect can be specified in the branch branch thus selected (selected branch), and the defect cause that is most likely is specified.
Then, the specified failure cause information is sent to the display control unit 36, and the display control unit 36 displays the failure cause and the countermeasure method thereof on the display device 24 as described later.

The display control unit 36 includes the key input device 23.
In accordance with a display mode screen call command desired by the operator, the specified display mode image data is created based on the display image creation / control program created in advance. That is, when an operator's command to call a predetermined display mode screen arrives, the display processing unit 36
For example, first, a line is drawn to generate frame line data, etc., of straight lines and curves required for the image, and then color paint of a predetermined color is applied to the inside and outside of each of the generated frames (color coloring) In addition, the data stored in the molding condition setting storage unit 31, the measured value storage unit 33, the monitor data monitoring processing unit 34, and the data sent from the defect cause determination unit 35 are fetched as necessary, and The character image data necessary for the display of the display mode screen is created by referring to the character data and the like that is created and stored in advance in the display fixed data storage unit (not shown), and this character image data is specified. Fit into the area,
Thereby, image data for display is generated. And
The image data generated by the display processing unit 36 is sent to the display device 24, and the image desired by the operator is displayed on the display screen of the display device 24.

FIG. 2 shows a defect countermeasure screen which the operator calls on the display screen 24a of the display device 24 by appropriately operating the keys. In the figure, reference numeral 41 denotes a defective item selection field. In the defective item selection field 41, the operator designates a defective item (defect phenomenon) with a cursor and pushes, for example, an enter key or the like. The analysis process of the cause of the defect due to is started. The figure shows a case where "short" is designated in the defective item selection column 41, and "short" is displayed in the defective item display column 42. Below the defect item display field 42, a defect cause display field 43 and a countermeasure method display field 44 are provided. In the defect cause display field 43, the defect cause identified by the processing by the defect cause determination section 35 is provided. Is displayed, and a countermeasure method for eliminating the cause of the defect is displayed in the countermeasure method display field 44 with, for example, a priority order.

FIG. 2 shows a case where "insufficiency of measurement" is specified as a cause (occurrence factor) of the "short circuit". For example, in this embodiment, another "short circuit" surrounded by a broken line in the drawing is shown. The cause and the countermeasure method thereof are not displayed, but only the "measurement insufficient" is displayed in the defect cause display column 43, and only the countermeasure method against the "measurement insufficient" is displayed in the countermeasure method display column 44. In addition, the parts surrounded by broken lines in the figure are collectively displayed, and the display corresponding to "insufficient weighing" is displayed on the top row, or the display corresponding to "insufficient weighing" is displayed in a color that distinguishes it from others. Alternatively, the identified cause and its countermeasure may be displayed by blinking or displaying it.

FIG. 3 is an explanatory diagram showing a flow of processing for identifying the cause of the "short circuit" in the defect cause judging section 35. When "short circuit" is input and designated as the defect phenomenon of the molded product, the defect cause determination unit 35 causes the measured value storage unit 33 to change the value based on the defect cause analysis program created in advance.
Monitor data related to the cushion amount is extracted as the monitor item data with the highest priority (importance) that should be judged at the beginning, which is closely related to the defect phenomenon of "short circuit". First, it is determined whether or not the stroke corresponding to the amount of resin remaining on the tip side is an appropriate amount.

When the cushion amount is less than an appropriate amount value (for example, 3 to 5 mm), the defect cause judging section 35 causes the "short circuit" to be caused during the kneading / plasticizing / measuring process (at the charging process). It was specified that the amount of molten resin was insufficient (the amount of molten resin that can be stored on the screw tip side) was insufficient, and if the cushion amount was more than the appropriate amount, the cause of the “short” was the cause during the injection stroke. It is specified that the holding pressure switching position (stroke position of the screw that switches from primary injection to holding pressure) is defective, and if the cushion amount is appropriate, the cause of the "short circuit" is identified from another point of view. Then, the second determination process for

That is, when the cushion amount is appropriate in the above-described first-stage determination process, the defect cause determination unit 3
Reference numeral 5 extracts monitor data relating to the holding pressure switching position from the measured value storage unit 33 and determines whether or not the relationship between the cushion amount and the holding pressure switching position is appropriate. If there is an abnormality such that the cushion amount comes behind the holding pressure switching position (normally, the holding pressure switching position comes slightly before the cushion amount), the cause of the "short" is the injection. If it is specified that the holding pressure switching position during the stroke is defective, and if the relationship between the cushion amount and the holding pressure switching position is correct, the cause of the "short circuit" is the insufficient filling pressure during the injection stroke. Specify that there was.

FIG. 4 shows "burrs" in the defect cause judging section 35.
It is explanatory drawing which shows the flow of the process for identifying the cause of. When "burr" is input and designated as the defect phenomenon of the molded product, the defect cause determination unit 35 similarly causes the measured value storage unit 33 to change the value based on the defect cause analysis program created in advance.
The injection pressure data near the holding pressure switching position is extracted as the monitor item data with the highest priority (importance) that should be judged at the beginning, which is closely related to the failure phenomenon called "burr", and the holding pressure is based on this. Check the slope of the pressure change near the switching position,
First, it is determined whether or not the gradient of this pressure change is appropriate.

If the inclination of the pressure change near the holding pressure switching position is small (the change is small), the defect cause determining unit 35 causes the "burr" to be the defective holding pressure switching position during the injection stroke. If there is no abnormality in the slope of the pressure change near the holding pressure switching position, the process proceeds to the second determination process for identifying the cause of “burr” from another viewpoint.

That is, when there is no abnormality in the slope of the pressure change in the vicinity of the pressure holding switching position in the above-described first-stage determination processing, the defect cause determination unit 35 determines that the screw in the pressure holding process (pressure holding stroke). Data regarding the moving amount is taken out from the measured value storage unit 33, and it is determined whether the screw moving amount in the pressure holding process is larger or smaller than the reference data.
Then, if the moving amount of the screw is small, it is specified that the cause of the “burr” is poor flow of the molten resin, and if the moving amount of the screw is large, the cause of the “burr” is excessive pressure. Specify that there was.

In addition, defective phenomena other than "short" and "burr" (for example, "flow mark", "crack", "jetting", "sink", "silver", "bubble", "burn, black spot") In the same manner, the selection process based on the monitor item data to be determined for the defect phenomenon is performed by the defect cause determination unit 35.
Is executed and the cause of the failure phenomenon is automatically identified.

Then, the cause of the identified defect phenomenon and the countermeasure method corresponding to this cause are displayed on the defect countermeasure screen of the display device 24 as described above.

[0036]

As described above, according to the present invention, a job for identifying a cause (a cause) of a time-consuming defective molded article, which has conventionally depended on the experience and intuition of an experienced worker,
Since the molding machine itself does it automatically, you can take corrective measures quickly and reliably. Therefore, it is possible to provide a convenient molding machine with a function of analyzing the cause of defective molded products, and its value is enormous.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a main configuration of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a defect countermeasure screen according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the flow of processing for identifying the cause of a “short” in the defect cause determination unit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a flow of processing for identifying the cause of “burr” in the defect cause determination unit according to the embodiment of the present invention.

FIG. 5 is an explanatory view showing an example of a display form displayed on a defect countermeasure screen of a conventional injection molding machine.

[Explanation of symbols]

 1 Mold opening / closing mechanism system 10 Injection mechanism system 20 Microcomputer (microcomputer) 21 Sensor group 22 Driver group 23 Key input device 24 Display device 31 Molding condition setting storage section 32 Molding process control section 33 Measured value storage section 34 Monitor data monitoring processing section 35 Failure Cause Determining Section 36 Display Control Section

Claims (2)

[Claims] 1. A molding machine having a function of executing a molding operation on the basis of a preset molding operation condition value and storing measured values of a number of predetermined monitor items during the molding operation, by the operator When the defect phenomenon of is specified, the determination process is performed based on the actual measurement value of the monitor item with the highest priority to be determined for the cause of the defect phenomenon, and the branching according to the determination result ( Selection processing by classification), and thereafter, if necessary, the branching branch (selected branch) selected in the above processing is subjected to determination processing based on the actual measurement values of the other monitor items, and the determination result is determined. The selection process by branching is repeated as many times as necessary, and the above-mentioned selection process identifies the most probable cause of failure. A molding machine that has a function to analyze the cause of defective molded products. 2. The molding machine having a molded product defect cause analysis function according to claim 1, wherein the identified cause of the defect is displayed on a display device together with a countermeasure method therefor.